Maharashtra Board Class 9 Science Chapter 15 Life Processes in Living Organisms Solutions

Std 9 Science Chapter 15 Life Processes In Living Organisms Question Answer Maharashtra Board

Class 9 Science Chapter 15 Life Processes In Living Organisms Question Answer Maharashtra Board

Question 1. Match the pairs and explain.

🎯 Exam Tip: Understanding different types of tropic movements and their stimuli is crucial. Pay attention to examples for each movement to score well.

Question 2. Complete the paragraph.

The milk was on the stove. Rasika was engrossed in watching television. She smelled something burning. She ran towards the kitchen. The milk was boiling over. She held the vessel with her bare hands but, screaming, she let it go at once. This activity was controlled by .............. cells. Special ends of .............. in these cells collected the information, from where it was transferred to the .............. and then towards the terminal end of the .............. The chemicals produced at the terminal end passed through the minute space i.e. .............. In this way, .............. were conducted in the body and the process of .............. was completed by conducting the impulses from .............. to ..............
(Nerve, muscle cell, impulse, dendrite, synapse, axon, reflex action, cell body)
Answer:
nerve, dendrite, cell body, axon, synapse, impulses, reflex action, nerve, muscle cell.
In simple words: This paragraph describes a reflex action sequence. When Rasika touched the hot vessel, nerve cells received the stimulus through dendrites, sent it to the cell body, then along the axon to the synapse, where impulses triggered a reflex action, causing her to withdraw her hand instantly.

🎯 Exam Tip: Accurately identifying the components of a reflex arc (receptor, sensory neuron, relay neuron, motor neuron, effector) and their sequence is key for answering such questions.

3. Write Notes On Root Pressure, Transpiration, Nerve Cell, Human Brain, Reflex Action

Question 4. Name the hormones of the following endocrine glands and the function of each. Pituitary, Thyroid, Adrenal, Thymus, Testis, Ovary.

Question 1. Life Processes In Living Organisms Class 9. Pituitary:
Answer:

🎯 Exam Tip: Memorize the key hormones produced by the pituitary gland and their primary functions, as this gland plays a central role in the endocrine system.

Question 2. Class 9 Science Chapter 15 Life Processes In Living Organisms. Thyroid
Answer:

🎯 Exam Tip: Focus on Thyroxine's role in metabolism and growth, and Calcitonin's role in calcium regulation, as these are fundamental functions of the thyroid gland.

Question 3. Life Processes In Living Organisms Class 9 Exercise. Adrenal
Answer:

🎯 Exam Tip: Remember Adrenalin's role in stress responses (emergency hormone) and Corticosteroids' involvement in mineral balance and metabolism.

Question 4. 9th Class Science Chapter 15 Life Processes In Living Organisms Exercise. Thymus
Answer:

🎯 Exam Tip: Connect the thymus gland directly to the immune system, specifically its role in T-cell development, which is the primary function of Thymosin.

Question 5. Testis
Answer:

🎯 Exam Tip: Focus on testosterone's role in male secondary sexual characteristics and its general importance in male reproductive system development.

Question 6. Std 9 Science Chapter 15 Life Processes In Living Organisms. Ovary
Answer:

🎯 Exam Tip: Differentiate the primary roles of oestrogen (secondary sexual characteristics, endometrium proliferation) and progesterone (maintaining pregnancy, preparing endometrium) for accurate answers.

Question 5. Draw and label the diagrams. Human endocrine glands, Human brain, Nephron, Nerve cell, Human excretory system.

Question 1. Human endocrine glands
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव शरीर में विभिन्न अंतःस्रावी ग्रंथियों जैसे हाइपोथैलेमस, पीनियल ग्रंथि, पिट्यूटरी ग्रंथि, थायराइड ग्रंथि, पैराथायराइड ग्रंथि, थाइमस, अधिवृक्क ग्रंथियां, अंडाशय और वृषण को उनके सही स्थानों पर स्पष्ट रूप से नामांकित करता है। यह मानव अंतःस्रावी तंत्र की शारीरिक स्थिति को दर्शाता है।
In simple words: This question requires drawing and labeling the various endocrine glands in the human body, such as the pituitary, thyroid, adrenal, and gonads, to illustrate their anatomical positions within the endocrine system.

🎯 Exam Tip: For diagrams, ensure clear and accurate labeling of all specified glands. Practice drawing them to remember their relative positions and shapes.

Question 2. Human brain
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव मस्तिष्क की संरचना को दर्शाता है, जिसमें प्रमस्तिष्क के वलन, पोंस, अनुमस्तिष्क, रीढ़ की हड्डी और मेडुला ऑब्लोंगटा जैसे प्रमुख भागों को स्पष्ट रूप से दर्शाया गया है। यह मस्तिष्क की जटिल शारीरिक रचना को समझने में मदद करता है।
In simple words: The human brain diagram should accurately show and label major parts like the cerebrum, cerebellum, pons, medulla oblongata, and spinal cord, illustrating its complex structure and protective coverings.

🎯 Exam Tip: Focus on the three main parts of the brain (cerebrum, cerebellum, brainstem) and their associated structures. Clear labels are crucial for scoring.

Question 3. Nephron
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र वृक्क की कार्यात्मक इकाई, नेफ्रॉन की विस्तृत संरचना को दर्शाता है, जिसमें बोमैन कैप्सूल, समीपस्थ संवलित नलिका, ग्लोमेरुलस, कॉर्टेक्स, मेडुला, हेनले का लूप, संग्रह नलिका और मूत्रवाहिनी से इसका संबंध शामिल है। यह वृक्क के निस्पंदन तंत्र को समझने के लिए महत्वपूर्ण है।
In simple words: This question requires drawing a nephron, the kidney's filtering unit, and labeling its components like Bowman's capsule, glomerulus, renal tubules, loop of Henle, and collecting duct, which are involved in urine formation.

🎯 Exam Tip: Pay attention to the correct sequence of structures in the nephron (Bowman's capsule to collecting duct) and accurately label each part to reflect its role in filtration and reabsorption.

Question 4. Nerve cell
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक न्यूरॉन (तंत्रिका कोशिका) की संरचना को दर्शाता है, जिसमें नाभिक, डेंड्राइट्स, कोशिका काय, अक्षतंतु, मायलिन शीथ, श्वान कोशिका, रैनवियर नोड और अक्षतंतु टर्मिनल शामिल हैं। यह तंत्रिका आवेगों के संचरण की प्रक्रिया को समझने में मदद करता है।
In simple words: A nerve cell (neuron) diagram should depict its main parts: dendrites for receiving signals, a cell body containing the nucleus, an axon for transmitting signals, and an axon terminal, often with a myelin sheath for insulation.

🎯 Exam Tip: Ensure your nerve cell diagram clearly shows the cell body, dendrites, axon, and axon terminals. Labeling the direction of impulse transmission is also beneficial.

Question 5. Human excretory system
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव उत्सर्जन तंत्र को दर्शाता है, जिसमें गुर्दे, मूत्रवाहिनी, मूत्राशय और मूत्रमार्ग के साथ-साथ संबंधित रक्त वाहिकाएं जैसे इन्फीरियर वेना कावा, अधिवृक्क ग्रंथि, रीनल धमनी, रीनल पेल्विस, रीनल शिरा, मेडुला, कॉर्टेक्स और एब्डोमिनल एओर्टा शामिल हैं। यह शरीर से अपशिष्ट पदार्थों को हटाने की प्रक्रिया को स्पष्ट करता है।
In simple words: This question asks for a diagram of the human excretory system, showing the kidneys, ureters, urinary bladder, and urethra, along with major blood vessels like the renal artery and vein, to illustrate the path of urine formation and elimination.

🎯 Exam Tip: Accurately draw and label the kidneys, ureters, bladder, and urethra. Showing the associated blood supply (renal artery/vein) adds completeness to the diagram.

Question 6. Answer the following.

(a) Explain chemical co-ordination in humans and give the names and functions of some hormones.
Answer:

• In humans chemical co-ordination is brought about with the help of certain chemical substances called hormones.
• Hormones are secreted by endocrine glands. These glands are also called ductless glands.
• These glands do not have any arrangement of their own to either store or carry their secretions. So, the hormones are directly released into the blood circulation.
• Though the endocrine glands are present at specific locations in our body, their secretions reach all parts of the body via the blood.
• Endocrine glands along with the nervous systems are responsible for control and co-ordination in our body. These two systems help each other to control and integrate the various activities of the body.
• A marked difference between these two systems is that nerve impulses are fast but short-lived whereas the actions of hormones are very slow but long-lasting.
• It is very important that hormones are secreted only in the required quantity and there is a special mechanism which controls the quantity and timing of hormone secretion.
• For example, whenever there is an increase in blood glucose level, certain cells in the pancreas get stimulated and as a response, they release a greater quantity of insulin, thus bringing down the sugar level to normal.

🎯 Exam Tip: When explaining chemical coordination, highlight the role of hormones, endocrine glands (ductless), and their slow but long-lasting effects. Providing examples like insulin's function adds significant value.

(b) Explain the difference between the excretory system of humans and plants.
Answer:

🎯 Exam Tip: Focus on the presence of a specialized system in humans versus its absence in plants, and list specific waste products for both to clearly differentiate them.

(c) Explain co-ordination in plants with the help of suitable examples.
Answer:

• Plants do not have systems like the nervous system or muscular system.
• In plants, movements are mainly in the form of responses given to the stimuli.
• Plants show two types of movements - growth relevant movements and growth irrelevant movements.
• Movement or growth of any part of the plant in response to an external stimulus is called tropism or tropic movement.
• Examples of growth-relevant movements are :
• The shoot system of any plant responds to the light stimulus i.e., it grows towards the source of light. This is called phototropic movement.
• The root system of plants responds to stimuli like gravitation and water. These responses are called gravitropic movement and hydrotropic movement respectively.
• Movement shown by plants in response to specific chemicals is called chemotropic movement.
• For example, the growth of the pollen tube towards the ovule.
• Some specific movements of the plants do not lead to the plant growth.
• Such movements are called growth-irrelevant movements.
• As a response to changes in the surroundings, plant hormones bring about various movements in plants.
• Examples of growth irrelevant movements are closing of leaflets of Touch-me-not (Mimosa) plant on touch.
• In the plant called Venus fly trap, when an insect visits the flower like trap, the trap closes up and the trapped insect is digested by the plant.
• The lotus flower opens during day-time while that of the tuberose opens at night.
• In plants like Touch-me-not (Mimosa), movement also occurs at places other than where it has been touched.
• Hence, we can infer that the information about the touch must have been released within the plant from one place to another.
• Plants use electrochemical impulses for transfer of information from one place to another.
• Plant cells change their shape by increasing or decreasing the water content and thereby, bring about the movements of plants.

🎯 Exam Tip: Clearly distinguish between growth-relevant (tropisms) and growth-irrelevant movements with specific examples for each. Mentioning the role of plant hormones and electrochemical signals is key.

Question 7. Explain in your own words with suitable examples. (a) What is meant by co-ordination?
Answer:

• Several different organ systems function in multicellular organisms.
• Their life goes on smoothly if there is co-ordination between different organ systems or organs and the stimuli in the surrounding.
• Depending upon this, we can say that systematic regulation of different processes can be called control and bringing about the different processes in the proper sequence is called co-ordination.
• If any activity in the body is to be completed successfully, proper co-ordination between different systems, and organs participating at different steps of that activity is necessary.
• If due to lack of co-ordination, there is confusion at any step, the activity may not get completed. There should be no randomness at any step.
• There should be proper co-ordination between internal activities of the body resulting from various factors like body temperature, water- level, enzyme-level, etc. or stimuli arising in the surrounding environment.
• Proper co-ordination between various systems of an organism helps to maintain a state of equilibrium called homeostasis which is necessary for the optimal efficiency of the body.

🎯 Exam Tip: Define co-ordination as the harmonious functioning of various systems and processes. Emphasize its role in achieving a specific outcome and maintaining homeostasis for optimal body efficiency.

(b) How does excretion occur in human beings?
Answer:

• Removal of wastes from the body is very important and it is the excretory system that carries out this function.
• The human excretory system consists of a pair of kidneys, a pair of ureters, the urinary bladder and the urethra. Urine is formed by the kidneys by separating the waste and unwanted excess substances from the blood.
• The functional unit of the kidney that performs the basic function of filtration is called a nephron. The urea produced in the liver comes into the blood.
• When the urea-containing blood comes into the glomerulus, it is filtered through capillaries and urea and other similar substances are separated from it.
• Water molecules and small molecules of some other substances can cross the semipermeable membrane of Bowman's capsule.
• The solution accumulated in the cavity of Bowman's capsule passes into the tubular part of the nephron. Here, molecules of water and some other useful substances are reabsorbed into the blood.
• Urine is formed from the remaining solution which is full of waste materials. The urine is carried by the ureters and stored in the urinary bladder. Afterwards, urine is given out through the urethra.

🎯 Exam Tip: Describe the pathway of urine formation, starting from blood filtration in the glomerulus/Bowman's capsule, through reabsorption in the tubules, and finally storage and expulsion. Naming the key organs (kidneys, ureters, bladder, urethra) is essential.

(c) How is excretion in plants useful to human beings?
Answer:

• Plants give out oxygen during photosynthesis by diffusion which is useful to human beings for respiration.
• Some waste materials of plants for example, gum, resin, latex of rubber, etc. are useful to humans.

🎯 Exam Tip: Highlight oxygen release as a primary benefit and list specific plant waste products (gum, resin, latex) that have economic or practical uses for humans.

(d) Describe the transportation system in plants.
Answer:

• Plants have two types of conducting tissues i.e., xylem which conducts water and phloem which conducts food.
• During transpiration, water is released into the atmosphere.
• As a result, water level is the epidermal layer of the leaf decreases.
• Water is brought up to the leaves through the xylem so as to compensate for the lost water.
• Transpiration helps in absorption of water and minerals and distribution to all parts of the plant whereas root pressure preforms the important role of pushing the water up at night time.
• The food produced by leaves is transported to each cell of the plant through phloem.
• When the food material like sucrose is transported towards a part of the plant through phloem, using ATP, the water concentration in that part decreases.
• As a result, water enters the cell by diffusion. The pressure on the cell wall increases due to increase in the cellular contents.
• Due to the increased pressure, food is pushed into the neighboring cells where the pressure is low.
• This process helps the phloem to transport the materials as per the need of the plant.

🎯 Exam Tip: Clearly explain the roles of xylem (water/minerals via transpiration/root pressure) and phloem (food/sugars via translocation) as the two primary conducting tissues in plants. Mentioning the energy requirement for translocation is important.

Class 9 Science Chapter 15 Life Processes In Living Organisms Intext Questions And Answers

Question 1. Class 9 Science Chapter 15 Life Processes In Living Organisms Exercise. How do the digestive system and respiratory system work?
Answer:
(a) Digestive system:

• The digestive system is responsible for digestion of food. i.e. breaking down complex insoluble food into simpler soluble form.
• The digestive system is made up of alimentary canal and digestive glands.
• The alimentary canal is a long and muscular tube of varying diameter which extends from the mouth to the anus.
• The digestive glands associated with alimentary canal are salivary glands, gastric glands, liver and pancreas.
• The process of digestion includes various stages wherein the food passes through the different organs of the alimentary canal and there it is digested part by part with the help of various enzymes secreted from the digestive glands.
• After the food is digested, the important nutrients are absorbed into the blood and the undigested food and residue of digested food is removed out of the body through the anus.

🎯 Exam Tip: When describing the digestive system, list the main organs of the alimentary canal and the associated digestive glands. Emphasize the breakdown of food and absorption of nutrients.

(b) Respiratory system:

• Respiration is the process of release of energy from the assimilated food.
• The respiratory system consists of nose, pharynx, larynx, trachea, bronchi and lungs (alveoli).
• Oxygen enters our body through breathing.
• This oxygen is taken to the cells and with the help of oxygen, food is oxidized into the cells to release energy in the form of ATR
• During this process, carbon dioxide and water vapour are given out as by-products which are given out during breathing.

🎯 Exam Tip: For the respiratory system, focus on the pathway of air, the role of oxygen in energy release, and the exhalation of carbon dioxide. Mentioning the coordinated function with the digestive system is a good point.

Question 2. Life Processes In Living Organisms Exercise. Previously you have performed the activity of observing a branch covered in a plastic bag. What did you observe in that activity?
Answer:

• When a branch is covered in a plastic bag, we observe that small droplets of water accumulate on the inner side of the plastic bag.
• This shows that leaves release water in the form of vapour through the stomata during transpiration. These vapours get condensed to form water droplets and accumulate inside the bag.

🎯 Exam Tip: Clearly state the observation (water droplets) and link it directly to the process of transpiration by leaves through stomata, explaining the condensation of water vapor.

Question 3. Life Process In Living Organism Exercise. Which are the sensory organs of an organism? What is their function?
Answer:

• Sensory organs of an organism are eyes, ears, tongue, skin and nose.
• The eyes help the organism to perceive the sensation of light to see the objects around it.
• The ears help the organism to perceive the sensation of sound and also perceive the sensation of pressure.
• The tongue helps to perceive different tastes and also in chewing the food.
• The skin helps to perceive the sensation of touch, pain, pressure etc.
• Some insects also possess antennae for sensing the changes in the environment.

🎯 Exam Tip: List the five main human sensory organs and clearly state one primary function for each. Mentioning antennae in insects shows broader biological understanding.

Question 4. 15 Life Processes In Living Organisms Class 9. Where are the gustatory and olfactory nerves to be found?
Answer:

• Gustatory nerves are concerned with sense of taste whereas olfactory nerves are concerned with the sense of smell.
• Gustatory nerves are found in the tongue from where they carry impulses to the gustatory cortex in the brain.
• Whereas the olfactory nerves are found in the nasal passage from where they carry impulses to the olfactory lobes in the brain.

🎯 Exam Tip: Remember that gustatory nerves are for taste (tongue) and olfactory nerves are for smell (nasal passage). Clearly state their locations and the senses they mediate.

Answer The Following Questions:

Question 1. Why do we eat fruits and vegetables? Do the plants also need minerals like we do?
Answer:

• We eat fruits and vegetables to get nutrients like carbohydrates, vitamins, minerals and fibers. These nutrients are important for the proper functioning of the body.
• Plants too need minerals for their growth and development.

🎯 Exam Tip: When answering, specify the types of nutrients we get from fruits/vegetables and explicitly state that plants also have a mineral requirement for their life processes.

Question 2. Life Processes In Living Organisms Class 9 Notes. From where do plants get inorganic substances other than carbon dioxide and oxygen?
Answer:
Plants get inorganic substances like nitrogen, phosphorus, magnesium, manganese, sodium etc. from the soil. Soil is the nearest and richest source of these elements.
In simple words: Plants primarily obtain inorganic substances such as nitrogen, phosphorus, magnesium, and manganese from the soil, which serves as their richest and most accessible source for these essential elements.

🎯 Exam Tip: State that plants obtain these minerals from the soil. Naming a few specific examples of these inorganic substances (e.g., nitrogen, phosphorus) strengthens the answer.

Question 3. 9th Std Science Chapter 15 Life Processes In Living Organisms. At least a small quantity of garbage or waste is produced every day in each house. What will happen if you keep this garbage for many days in your house?
Answer:

• If we keep garbage for many days in our house, it will start decaying due to the growth of decomposers like fungi and bacteria.
• This will result in foul odour and will also lead to spread of diseases.

🎯 Exam Tip: Focus on two main consequences: decomposition leading to foul odor and the proliferation of disease-causing microorganisms or pests.

Question 4. Life Processes In Living Organisms Exercise Class 9. Sometimes, while eating we bite our own finger or tongue by mistake.
Answer:

• Sometimes, while eating we over-fill our mouth causing the bite to misalign, thus we bite our own finger or tongue by mistake.
• If we are dehydrated, the muscles of the mouth and tongue do not function properly causing us to bite our own tongue.
• If we are distracted with other activities while eating, it can cause us to bite our tongue or finger.
• Thus, due to lack of co-ordination sometimes while eating, we bite our own finger or tongue by mistake.

🎯 Exam Tip: Emphasize "lack of co-ordination" as the central reason. Provide examples like overfilling the mouth or distraction as contributing factors.

Question 5. 9th Class Science 15 Chapter Life Processes In Living Organisms. Sometimes, we choke while eating in a hurry.
Answer:

• There is an elastic flap at the starting of the wind-pipe called epiglottis which opens whenever we breathe in air and closes to prevent the entry of food into the respiratory system.
• While eating in hurry, due to lack of co-ordination, the epiglottis opens to take in air but food too enters in causing us to choke.

🎯 Exam Tip: Explain the role of the epiglottis and how a momentary lapse in coordination (e.g., due to hurry) causes food to enter the windpipe, leading to choking.

Question 6. Life Processes In Living Organisms Class 9 Extra Questions. An injury to the medulla oblongata can lead to death. Why?
Answer:

• The medulla oblongata controls involuntary activities like the beating of the heart, blood circulation, breathing etc.
• An injury to the medulla oblongata will stop these activities, leading to death.

🎯 Exam Tip: Clearly state that the medulla oblongata controls vital involuntary functions. Listing examples like heart beat and breathing will help explain why its injury is lethal.

9th Std Science Chapter 15 Life Processes In Living Organisms Question 3. At least a small quantity of garbage or waste is produced every day in each house. What will happen if you keep this garbage for many days in your house?
Answer:- If we keep garbage for many days in our house, it will start decaying due to the growth of decomposers like fungi and bacteria. - This will result in foul odour and will also lead to spread of diseases.In simple words: Keeping garbage for long attracts decomposers, causing foul smells and spreading diseases, highlighting the need for proper waste disposal.

🎯 Exam Tip: Focus on the ecological impact and public health consequences of waste accumulation for scoring points.

Life Processes In Living Organisms Exercise Class 9 Question 4. Sometimes, while eating we bite our own finger or tongue by mistake.
Answer:- Sometimes, while eating we over-fill our mouth causing the bite to misalign, thus we bite our own finger or tongue by mistake. - If we are dehydrated, the muscles of the mouth and tongue do not function properly causing us to bite our own tongue. - If we are distracted with other activities while eating, it can cause us to bite our tongue or finger. - Thus, due to lack of co-ordination sometimes while eating, we bite our own finger or tongue by mistake.In simple words: Biting your finger or tongue while eating is often due to overfilling the mouth, dehydration affecting muscle function, or distraction leading to a temporary lapse in body co-ordination.

🎯 Exam Tip: Relate the answer to the concept of body co-ordination and muscle control for a complete explanation.

9th Class Science 15 Chapter Life Processes In Living Organisms Question 5. Sometimes, we choke while eating in a hurry.
Answer:- There is an elastic flap at the starting of the wind-pipe called epiglottis which opens whenever we breathe in air and closes to prevent the entry of food into the respiratory system. - While eating in hurry, due to lack of co-ordination, the epiglottis opens to take in air but food too enters in causing us to choke.In simple words: Choking while eating happens because the epiglottis, a flap that normally covers the windpipe during swallowing, fails to close completely due to rushed eating, allowing food to enter the respiratory tract.

🎯 Exam Tip: Emphasize the role of the epiglottis and the importance of proper co-ordination between breathing and swallowing.

Life Processes In Living Organisms Class 9 Extra Questions Question 6. An injury to the medulla oblongata can lead to death. Why?
Answer:- The medulla oblongata controls involuntary activities like the beating of the heart, blood circulation, breathing etc. - An injury to the medulla oblongata will stop these activities, leading to death.In simple words: Damage to the medulla oblongata is fatal because it controls essential involuntary life functions such as heartbeat, blood circulation, and breathing.

🎯 Exam Tip: Highlight the medulla oblongata's critical role in regulating vital involuntary bodily functions.

Life Processes In Living Organisms Class 9 Maharashtra Board Question 7. You may have seen how a drunken person struggles to maintain his body balance. An excess of alcohol in the body causes one to lose control over it. Why does this happen? Find out the reason with help of the internet.
Answer:- The cerebellum co-ordinates voluntary movements and maintains balance of the body. - An excess of alcohol causes dysfunctioning of the cerebellum. - It results in primary loss of co-ordinated movements and loss of balance.In simple words: Alcohol impairs the cerebellum, the brain region responsible for co-ordinating voluntary movements and maintaining balance, leading to a loss of physical control.

🎯 Exam Tip: Focus on the specific brain part (cerebellum) and its function in co-ordination and balance, linking it directly to the effects of alcohol.

9th Life Processes In Living Organisms 5 Question 8. Why does this happen?
(a) Leaves of plants fall off in a particular season.
Answer:- Plants lose water through their leaves by transpiration. So some plants shed their leaves in dry season to reduce transpiration and conserve water. - In plants, the waste substances are stored in the vacuoles of leaf-cells which are then shed along with the leaves in a specific season.In simple words: Plants shed leaves in specific seasons to reduce water loss via transpiration, especially in dry periods, and to excrete accumulated waste materials stored in leaf cells.

🎯 Exam Tip: Mention both water conservation and waste excretion as key reasons for leaf shedding.

(b) Fruits, flowers fall off after a certain period of time.
Answer:- In plants, waste substances are stored in the vacuoles of fruits and flowers. So, they fall off after some time to excrete these wastes. - Also, when fruits and flowers mature, the supply of nutrients to mature fruits and flowers is blocked. This causes abscission in that part of the plant leading to their detachment from the plant body and falling off.In simple words: Fruits and flowers fall off because they act as storage for plant waste products, and mature structures undergo abscission (detachment) due to blocked nutrient supply, facilitating waste removal and seed dispersal.

🎯 Exam Tip: Include both waste excretion and the physiological process of abscission due to nutrient blockage for a comprehensive answer.

(c) Substances like resin, gum, etc. are given out of the plant body.
Answer:- Resin, gum etc. are the waste products of plants. They are given out after some time as a process of excretion in plants. - Many plants, particularly, woody plants produce resin and gum in response to injury. These resin and gum act as bandage protecting the plants from invading insects and pathogens.In simple words: Plants release substances like resin and gum as waste products through excretion, which also serve a protective role by sealing injuries and deterring pests and diseases.

🎯 Exam Tip: Note both the excretory and protective functions of substances like resin and gum for plants.

15 Life Processes In Living Organisms Exercise Question 9. Which waste products are produced in our body through metabolic activities?
Answer:The waste products formed in our body through metabolic activities are urea, uric acid, ammonia, carbon dioxide etc.In simple words: Our bodies produce waste products like urea, uric acid, ammonia, and carbon dioxide through metabolic processes.

🎯 Exam Tip: List common metabolic waste products accurately to demonstrate understanding.

Life Processes In Living Organisms 9th Class Exercise Question 10. As compared to the monsoons and winter a very small quantity of urine is produced in the summer season. Why is it so?
Answer:In summer, we sweat more due to excess heat. So, the body tries to conserve water by reducing urine formation. This is to prevent dehydration.In simple words: Less urine is produced in summer because the body sweats more to cool down, leading to water conservation by the kidneys to prevent dehydration.

🎯 Exam Tip: Link increased sweating in summer directly to reduced urine output and water conservation by the body.

Question 11. In adults, the process of urination is under their control but not in infants. Why is it so?
Answer:- In adults, the muscles of the bladder are under the voluntary control. So the process of urination is under control. - In infants, the bladder muscles are not mature until about two years of age. So, the process of urination is not under control.In simple words: Adults can control urination because their bladder muscles are under voluntary control, while infants lack this control as their bladder muscles are not yet mature.

🎯 Exam Tip: Emphasize the development of voluntary muscle control over the bladder as the key difference between infants and adults.

Answer the following questions:

Question 1. Observe the following figures carefully.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र पौधों में होने वाली वृद्धि-संबंधी गतियों को दर्शाता है। इसमें तीन उप-चित्र हैं: पहला पराग नली का बीजांड की ओर बढ़ना (रसायन अनुवर्तन), दूसरा एक छोटे पौधे का सूर्य की ओर मुड़ना (प्रकाश अनुवर्तन), और तीसरा किसी सहारे के चारों ओर प्रतान (टेंड्रिल) का कुंडली बनाना (स्पर्श अनुवर्तन)। ये सभी गतियां पौधों की वृद्धि से संबंधित हैं।
Answer:Observations: - Figure 'A' shows chemotropic movement. Pollen tube grows towards the ovule in response to specific chemicals released by the ovule. - Figure 'B' shows phototropic movement. Shoot grows towards the Sun in response to stimulus of light. - Figure 'C' shows thigmotropic movement. Tendrils of climbers are sensitive to touch. When they come in contact with an object, they entwine around the object and cling to it. - All the above movements are related to growth. Hence, they are called growth relevant movements.In simple words: The figures illustrate growth-relevant plant movements: chemotropism (pollen tube to ovule), phototropism (plant towards light), and thigmotropism (tendril coiling), all being responses linked to growth.

🎯 Exam Tip: Clearly identify each type of tropic movement and its corresponding stimulus shown in the diagrams.

Question 2. Observe the pictures carefully and think about them.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र विभिन्न पौधों की तस्वीरें दिखाता है जिनमें वृद्धि-इर्राप्रसंगिक (growth-irrelevant) गतियां होती हैं। इसमें छुई-मुई का पौधा (स्पर्श के प्रति पत्तियां बंद होना), वीनस फ्लाई ट्रैप (कीट को फंसाना), कमल (दिन में खिलना), और बालसम (फलों का फटना) शामिल हैं। ये गतियां वृद्धि का परिणाम नहीं हैं बल्कि पर्यावरणीय उत्तेजनाओं के प्रति प्रतिक्रियाएं हैं।
Answer:- Figure 'A' shows touch-me-not (Mimosa) plant. In this plant, the leaflets close in response to stimulus of touch. - Figure 'B' shows Venus fly trap. In this plant, there is a trap that appears and smells like a flower and deceives the insect. When an insect visits that flower-like trap, the trap closes up and the trapped insect is digested by the plant. - Figure 'C' shows lotus plant. The lotus flower opens during day-time. - Figure 'D' shows Balsam plant. In this plant, the ripened fruit dehisces (bursts open) at the right time to disperse the seeds.In simple words: These pictures depict growth-irrelevant plant movements, such as the touch-me-not plant closing its leaves, the Venus fly trap capturing insects, the lotus flower opening during the day, and balsam fruits bursting to disperse seeds.

🎯 Exam Tip: Focus on describing the specific growth-irrelevant movement for each plant and its ecological significance.

Question 3. As you watch the match being played on your school ground, you will see the control and co-ordination among the movements of the players. Make a list of all such different actions.
Answer:In an inter-house basketball match, control and co-ordination is seen in dodging the ball, jumping, running, passing it to the team mates and dribbling the ball.In simple words: In a basketball match, players demonstrate control and co-ordination through actions like dodging, jumping, running, passing, and dribbling the ball.

🎯 Exam Tip: Provide a diverse list of actions that clearly showcase both control (precision in movement) and co-ordination (harmonious execution of multiple movements).

Question 4. Observe the figure carefully and as per the numbers in that figure, answer the following questions.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक प्रतिवर्त क्रिया (reflex action) के मार्ग को दर्शाता है। इसमें दिखाया गया है कि कैसे हाथ में लगे एक गर्म वस्तु के स्पर्श से संवेदी न्यूरॉन (sensory neuron) के माध्यम से आवेग मेरुरज्जु (spinal cord) तक पहुँचते हैं, जहाँ से एक अंतर-न्यूरॉन (association neuron) के माध्यम से प्रेरक न्यूरॉन (motor neuron) को प्रतिक्रिया का आवेग भेजा जाता है, जिससे हाथ की मांसपेशियां तुरंत सिकुड़ जाती हैं और हाथ हट जाता है।
(a) What is happening at 1 and 2?
Answer:At 1 stimulus of heat is received by thermo-receptors in the skin. At 2, the hand is withdrawn instantly.In simple words: At point 1, skin thermo-receptors detect a heat stimulus, leading to an instant withdrawal of the hand at point 2.

🎯 Exam Tip: Identify the specific receptor and the immediate, involuntary response clearly for this part.

(b) Which nerve carried the impulse to the point marked 3? In which direction is it conducting the impulse?
Answer:Sensory nerve carried the impulse to the point marked 3. The impulse is conducted from the skin towards the spinal cord.In simple words: The sensory nerve carries the impulse from the skin towards the spinal cord, reaching point 3.

🎯 Exam Tip: Clearly state both the type of nerve and the direction of impulse transmission.

(c) Which is the nerve shown by 4?
Answer:The nerve shown by 4 is association neuron. It is present in the gray matter of the spinal cord. It receives the sensory impulse, interprets it and generates impulse.In simple words: Point 4 represents an association neuron in the spinal cord's gray matter, which processes sensory impulses and generates a response.

🎯 Exam Tip: Identify the neuron type (association) and briefly explain its role in processing impulses within the spinal cord.

(d) Which is the organ marked as 5?
Answer:Spinal cord.In simple words: The organ labeled as 5 in the diagram is the spinal cord.

🎯 Exam Tip: Accurately name the labeled organ.

(e) At 6, which nerve is conducting the response impulse?
Answer:Motor nerve.In simple words: The motor nerve conducts the response impulse at point 6.

🎯 Exam Tip: Identify the motor nerve as responsible for transmitting response impulses from the spinal cord to effectors.

(f) At 7, where has the impulse reached? What is its effect?
Answer:At 7, the impulse has reached the muscles of the hand. As a result, the muscles contract and the hand is withdrawn instantly in response to the stimulus of heat.In simple words: At point 7, the impulse reaches the hand muscles, causing them to contract immediately and withdraw the hand from the heat stimulus.

🎯 Exam Tip: Describe both the target location of the impulse and the resulting physical action clearly.

Question 5. Sketch and label:
Answer:- Stimulus - Hand is withdrawn - Sensory neuron - Association neuron - Spinal cord - Motor neuron - MusclesIn simple words: To sketch and label a reflex action, include the stimulus, receptors, sensory neuron, spinal cord (with association neuron), motor neuron, and muscles, showing the pathway of impulse and response.

🎯 Exam Tip: Ensure all components of the reflex arc are accurately drawn and labeled with clear arrows indicating the direction of impulse flow.

(6) Observe the figure and list down functions for 'A' and 'B'
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव मस्तिष्क के ऊपरी दृश्य को दर्शाता है, जिसे दो मुख्य भागों- बायां गोलार्द्ध (Left brain) और दायां गोलार्द्ध (Right brain)- में विभाजित किया गया है। यह मस्तिष्क के कार्यात्मक पार्श्वीकरण (functional lateralization) को प्रस्तुत करता है, जहाँ प्रत्येक गोलार्द्ध विशिष्ट कार्यों से जुड़ा होता है।
Answer:

🎯 Exam Tip: Clearly distinguish the specialized functions attributed to each hemisphere of the brain.

Answer the following questions:

Question 1. Take a small plant like balsam or tuberose with its roots intact. Wash and clean its roots. As shown in the fig, keep it in the water containing a stain like safranin or eosin. Observe the stem and the veins of the leaves after 2-3 hours.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक प्रयोग को दर्शाता है जिसमें एक छोटे पौधे को रंगीन घोल (जैसे ईओसिन या सैफ्रानिन) वाले बीकर में रखा गया है। पौधे की जड़ें घोल में डूबी हुई हैं। तने और पत्तियों की शिराओं में रंग का ऊपर की ओर संचलन, मूल दाब (root pressure) के कारण जल और खनिजों के अवशोषण तथा जाइलम के माध्यम से उनके परिवहन को दर्शाता है।
Answer:- The stem and veins of the leaves appear pinkish in colour. - Due to the root pressure generated, eosin solution is continuously pushed upward. - As a result water reaches xylem and the water column is pushed forward.In simple words: When a plant is placed in a colored solution, the stem and leaf veins turn pink because root pressure causes the eosin solution to move upwards through the xylem, demonstrating water transport.

🎯 Exam Tip: Link the observation (pink color in stem/veins) directly to root pressure and xylem's role in water conduction.

Question 2. Take a transverse section of the stem of a plant and observe the stained xylem under a compound microscope.
Answer:The xylem elements appear pinkish as the eosin solution is conducted upwards through the xylem. From this we infer that the xylem is responsible for the conduction of water and minerals in the plant.In simple words: Observing a pinkish coloration in the xylem elements of a stained stem cross-section under a microscope confirms that xylem is responsible for transporting water and minerals.

🎯 Exam Tip: Emphasize the direct link between the observation of stained xylem and its inferred function in water and mineral transport.

Question 3. Observe your mother while she cuts the elephant's foot (Amorphophallus) or arum leaves. Your hands may also begin to itch if you try to cut these leaves. Why does this happen? Try to find out. Ask your mother what she does to prevent the itching.
Answer:- In some plants like elephant foot (Amorphophallus) or arum, waste materials are in the form of crystals of calcium oxalate. They are called raphides. - As they are needle-shaped, they prickle and cause irritation of the skin leading to itching. - This can be prevented by applying tartaric acid (tamarind) or citric acid (lemon) on the hands while cutting these vegetables as the acids dissolve the crystals of calcium oxalate.In simple words: Elephant foot or arum leaves cause itching due to needle-shaped calcium oxalate crystals called raphides. Applying acidic substances like tamarind or lemon juice dissolves these crystals, preventing irritation.

🎯 Exam Tip: Identify the specific chemical substance (calcium oxalate/raphides) and its physical property (needle-shaped) that causes irritation, along with the acidic remedy.

Class 9 Science Chapter 15 Life Processes in Living Organisms Additional Important Questions and Answers

Choose and write the correct options.

Question 1. The transport of food produced in leaves to each cell in the plant body is called
(a) Transpiration
(b) Root pressure
(c) Translocation
(d) Ascent of sap
Answer: (c) translocation
In simple words: The process of moving food from leaves to all parts of a plant is known as translocation.

🎯 Exam Tip: Remember translocation specifically refers to the transport of manufactured food (sugars) in plants.

Question 2. Kidneys filter blood about .................................... times every day.
(a) 100
(b) 200
(c) 300
(d) 400
Answer: (d) 400
In simple words: Kidneys filter blood approximately 400 times daily to remove waste and maintain bodily fluid balance.

🎯 Exam Tip: Memorize this specific biological statistic related to kidney function.

Question 3. About .................................... of blood is sent through the dialysis machine at one time.
(a) 500 ml
(b) 5 l
(c) 200 ml
(d) 400 ml
Answer: (a) 500 ml
In simple words: A dialysis machine processes about 500 ml of blood at one time to filter out waste products.

🎯 Exam Tip: Understand the typical volume of blood processed during a single cycle of dialysis.

Question 4. The movement of plant towards the source of light is called .................................... movement.
(a) chemotropic
(b) hydrotropic
(c) phototropic
(d) gravitropic
Answer: (c) phototropic
In simple words: A plant's movement towards a light source is termed phototropic movement.

🎯 Exam Tip: Associate "photo-" with light when identifying tropic movements.

Question 5. The movement of root system towards stimulus of gravity is called .................................... movement.
(a) phototropic
(b) gravitropic
(c) hydrotropic
(d) chemotropic
Answer: (b) gravitropic
In simple words: The root system's growth response towards gravity is known as gravitropic movement.

🎯 Exam Tip: Link "gravi-" with gravity when discussing plant tropic movements.

Question 6. The movement of root system towards stimulus of water is called .................................... movement.
(a) Phototropic
(b) Gravitropic
(c) Hydrotropic
(d) Chemiotropic
Answer: (c) hydrotropic
In simple words: The movement of a plant's root system in response to water is called hydrotropic movement.

🎯 Exam Tip: Remember "hydro-" refers to water in biological terms, especially for tropic movements.

Question 7. Hormone .................................... helps in stem elongation.
(a) Auxin
(b) Gibberellin
(c) Cytokinin
(d) Abscisic acid
Answer: (b) Gibberellin
In simple words: Gibberellin is the plant hormone primarily responsible for promoting stem elongation.

🎯 Exam Tip: Connect Gibberellin directly with stem growth and elongation in plants.

Question 8. Hormone .................................... helps in cell division.
(a) Auxin
(b) Gibberellin
(c) Cytokinin
(d) Abscisic acid
Answer: (c) Cytokinin
In simple words: Cytokinin is a plant hormone that stimulates and regulates cell division.

🎯 Exam Tip: Remember cytokinins are key for cell division and cytokinesis in plants.

Question 9. The hormone .................................... is effective in prevention and retardation of growth, leaf wilting, etc.
(a) Auxin
(b) Cytokinin
(c) Gibberellin
(d) Abscisic acid
Answer: (d) Abscisic acid
In simple words: Abscisic acid is a plant hormone that inhibits growth and promotes responses like leaf wilting, especially under stress conditions.

🎯 Exam Tip: Associate abscisic acid with dormancy and stress responses like growth inhibition and wilting.

Question 10. .................................... neurons conduct impulses from the sensory organs to the brain and the spinal cord,
(a) Sensory
(b) Motor
(c) Association
(d) All of these
Answer: (a) Sensory
In simple words: Sensory neurons are responsible for transmitting impulses from sensory organs to the brain and spinal cord.

🎯 Exam Tip: Understand that sensory neurons carry information *to* the central nervous system.

Question 11. The brain of an adult human weighs about ....................................
(a) 500 - 600 grams
(b) 2 – 3 kilograms
(c) 1300-1400 grams
(d) 1500-1600 grams
Answer: (c) 1300 – 1400 grams
In simple words: An adult human brain typically weighs between 1300 and 1400 grams.

🎯 Exam Tip: Memorize the approximate weight range of the adult human brain.

Question 12. .................................... is the largest part of the brain.
(a) Cerebrum
(b) Cerebellum
(c) Medulla oblongata
(d) Spinal cord
Answer: (a) Cerebrum
In simple words: The cerebrum is the largest and most prominent part of the human brain.

🎯 Exam Tip: Identify the cerebrum as the largest part responsible for higher-level functions.

Question 13. There are two triangular swollen structure called .................................... on the upper side of the medulla oblongata.
(a) Ventricles
(b) Meninges
(c) Pyramids
(d) Pons
Answer: (c) Pyramids
In simple words: Two triangular swollen structures, known as pyramids, are located on the upper side of the medulla oblongata.

🎯 Exam Tip: Recall the specific anatomical features associated with the medulla oblongata.

Question 14. Control of voluntary movements is done by ....................................
(a) Cerebrum
(b) Cerebellum
(c) Medulla oblongata
(d) Spinal cord
Answer: (a) Cerebrum
In simple words: Voluntary movements, such as walking or speaking, are controlled by the cerebrum.

🎯 Exam Tip: Distinguish between the functions of the cerebrum (voluntary actions) and cerebellum (co-ordination/balance).

Question 15. Co-ordination of voluntary movements is done by ....................................
(a) cerebrum
(b) cerebellum
(c) medulla oblongata
(d) spinal cord
Answer: (b) cerebellum
In simple words: The cerebellum is responsible for co-ordinating voluntary movements, ensuring they are smooth and balanced.

🎯 Exam Tip: Remember that while the cerebrum initiates voluntary movements, the cerebellum refines and co-ordinates them.

Question 16. Control of involuntary activities like the beating of the heart, blood circulation, breathing etc. are controlled by ....................................
(a) Spinal cord
(b) Cerebrum
(c) Cerebellum
(d) Medulla oblongata
Answer: (d) Medulla oblongata
In simple words: The medulla oblongata controls essential involuntary body functions such as heart rate, blood circulation, and breathing.

🎯 Exam Tip: Identify the medulla oblongata as the control center for vital, involuntary life processes.

Question 17. The function of cerebrum is to ....................................
(a) control of voluntary movements
(b) co-ordination of voluntary movements
(c) control of involuntary activities
(d) maintaining the body balance
Answer: (a) control of voluntary movements
In simple words: The primary function of the cerebrum is the initiation and control of voluntary movements.

🎯 Exam Tip: Focus on the cerebrum's role in conscious and intentional actions.

Question 18. The function of cerebellum is ....................................
(a) to control of voluntary movements
(b) to maintain the body balance
(c) to control of involuntary activities
(d) to co-ordinate of voluntary movements
Answer: (b) to maintain the body balance
In simple words: The cerebellum's main function is to maintain body balance and posture.

🎯 Exam Tip: Highlight the cerebellum's crucial role in balance and the refinement of motor skills.

Question 19. Hormone .................................... stimulates the liver to convert excess blood glucose into glycogen.
(a) Glucagon
(b) insulin
(c) Somatostatin
(d) Pancreatic polypeptide
Answer: (a) Glucagon
In simple words: Glucagon is a hormone that stimulates the liver to convert stored glycogen back into glucose, raising blood sugar levels.

🎯 Exam Tip: Distinguish glucagon's role (raising blood glucose) from insulin's (lowering blood glucose).

Question 20. Hormone .................................... controls behaviour during crisis and emotional situation.
(a) Thyroxine
(b) Parathormone
(c) Adrenalin and Nor adrenalin
(d) Somatostatin
Answer: (c) Adrenalin and Nor adrenalin
In simple words: Adrenalin and Nor adrenalin, also known as epinephrine and norepinephrine, are hormones that regulate the body's 'fight or flight' response during stressful or emotional situations.

🎯 Exam Tip: Associate adrenalin and nor-adrenalin with the body's emergency response system.

Question 21. .................................... controls menstrual cycle and ovulation.
(a) Prolactin
(b) Oxytocin
(c) Luteinizing hormone
(d) Progesterone
Answer: (c) Luteinizing hormone
In simple words: Luteinizing hormone (LH) plays a crucial role in regulating the menstrual cycle and triggering ovulation in females.

🎯 Exam Tip: Focus on LH's direct involvement in ovulation within the menstrual cycle.

Question 22. .................................... stimulates growth of secondary sexual characteristics in men.
(a) Thymosin
(b) Testosterone
(c) Oestrogen
(d) Thyroxine
Answer: (b) Testosterone
In simple words: Testosterone is the primary male sex hormone responsible for stimulating the development of secondary sexual characteristics in men.

🎯 Exam Tip: Correctly identify testosterone as the key hormone for male secondary sexual characteristics.

Question 23. .................................... occurs through stomata.
(a) Translocation
(b) Perspiration
(c) Transpiration
(d) Conduction
Answer: (c) Transpiration
In simple words: Transpiration, the process of water vapor release from plants, primarily occurs through small pores called stomata on leaves.

🎯 Exam Tip: Remember that stomata are the primary sites for gaseous exchange and water loss (transpiration) in plants.

Question 24. performs the important role of pushing the water up during the night time.
(a) Translocation
(b) Root pressure
(c) Transpiration pull
(d) None of these
Answer: (b) Root pressure
In simple words: Root pressure is the force generated in the roots that pushes water upwards in plants, especially noticeable at night when transpiration is low.

🎯 Exam Tip: Understanding root pressure is crucial for questions on water transport mechanisms in plants.

Question 25. In plants, gaseous substances are given out by .
(a) Root pressure
(b) Osmosis
(c) Diffusion
(d) Translocation
Answer: (c) diffusion
In simple words: Plants release gaseous waste products like oxygen (during photosynthesis) and carbon dioxide (during respiration) into the atmosphere through the process of diffusion.

🎯 Exam Tip: Diffusion is a fundamental process for gas exchange in plants, essential for both photosynthesis and respiration.

Question 26. Each kidney has approximately nephrons.
(a) 1 lakh
(b) 10,000
(c) 10 lakh
(d) 50 lakh
Answer: (c) 10 lakh
In simple words: Each human kidney contains about 10 lakh (1 million) tiny filtering units called nephrons, which are responsible for blood purification and urine formation.

🎯 Exam Tip: Knowing the approximate number of nephrons per kidney highlights the kidney's extensive filtering capacity.

Question 27. Insulin is secreted by the of the pancreas.
(a) Alpha cells
(b) Beta cells
(c) Delta cells
(d) F cells
Answer: (b) Beta cells
In simple words: Beta cells within the islets of Langerhans in the pancreas produce and secrete insulin, a hormone vital for regulating blood sugar levels.

🎯 Exam Tip: Recall the specific cells in the pancreas responsible for insulin production, as this is a common point in endocrine system questions.

Select The Odd Man Out:

Question 1. Skin, Brain, Kidneys, Lungs.
Answer: Brain - It is a controlling organ whereas the others are excretory organs.
In simple words: The brain is a control center, while skin, kidneys, and lungs are primarily involved in removing waste from the body.

🎯 Exam Tip: Focus on the primary function of each organ when identifying the odd one out in such classification questions.

Question 2. Gum, Resin, Urea, Latex
Answer: Urea - It is an excretory product of animals whereas the others are excretory products of plants.
In simple words: Urea is a waste product from animals, while gum, resin, and latex are waste products excreted by plants.

🎯 Exam Tip: Distinguish between animal and plant waste products when classifying biological substances.

Question 3. Gibberellin, Auxin, Thyroxine, Cytokinin.
Answer: Thyroxine - It is a hormone in animals whereas the others are hormones in plants.
In simple words: Thyroxine is an animal hormone; Gibberellin, Auxin, and Cytokinin are plant hormones.

🎯 Exam Tip: Remember to differentiate between hormones specific to plants and animals for accurate classification.

Question 4. Dendrite, Cell body, Axon, Synapse.
Answer: Synapse - It is a minute space between two adjacent neurons whereas the others are parts of the neuron.
In simple words: A synapse is the gap between neurons, whereas dendrite, cell body, and axon are structural components of a single neuron.

🎯 Exam Tip: Distinguish between the structural parts of a neuron and the junction where impulses are transmitted between neurons.

Question 5. Thyroxine, Calcitonin, Insulin, Auxin.
Answer: Auxin - It is a plant hormone whereas the others are hormones in human beings.
In simple words: Auxin is a plant hormone, while Thyroxine, Calcitonin, and Insulin are hormones found in humans.

🎯 Exam Tip: Pay attention to the organism (plant or animal) associated with specific hormones.

Complete The Analogy:

Question 1. Water: Xylem :: Food :
Answer: Phloem
In simple words: Just as xylem transports water in plants, phloem transports food.

🎯 Exam Tip: Xylem and phloem are the two primary vascular tissues in plants, with distinct transport functions.

Question 2. Movement of root system : Gravitropic :: Movement of shoot system :
Answer: Phototropic
In simple words: Roots grow in response to gravity (gravitropic), while shoots grow towards light (phototropic).

🎯 Exam Tip: Recall the specific tropic movements and the stimuli they respond to for different plant parts.

Question 3. Brain: Cranial Cavity :: Spinal Cord :
Answer: Vertebral column
In simple words: The brain is protected within the cranial cavity, just as the spinal cord is protected within the vertebral column.

🎯 Exam Tip: Understand the protective structures for major parts of the central nervous system.

Question 4. Cavities of the brain : Ventricles :: Cavities of the spinal cord :
Answer: Central canal
In simple words: The brain contains ventricles, which are cavities, similar to how the spinal cord contains a central canal.

🎯 Exam Tip: Familiarize yourself with the internal structural features, including cavities, of the brain and spinal cord.

Question 5. Involuntary activities : Medulla oblongata : : Balance of the body :
Answer: Cerebellum
In simple words: The medulla oblongata controls involuntary actions, while the cerebellum is responsible for maintaining body balance and coordination.

🎯 Exam Tip: Clearly differentiate the functions of various parts of the brain, especially for involuntary actions and coordination.

Question 6. Stem elongation: Gibberellin :: Cell division :
Answer: Cytokinin
In simple words: Gibberellin promotes stem elongation, and Cytokinin promotes cell division in plants.

🎯 Exam Tip: Associate specific plant hormones with their primary roles in plant growth and development.

Question 7. Control of voluntary movements : Cerebrum :: Co-ordination of voluntary movements :
Answer: Cerebellum
In simple words: Voluntary movements are initiated and controlled by the cerebrum, while the cerebellum coordinates these movements to ensure smoothness and balance.

🎯 Exam Tip: Understand the distinct but complementary roles of the cerebrum and cerebellum in motor control.

Question 8. Converts glucose to glycogen : Insulin :: Converts glycogen to glucose :
Answer: Glucagon
In simple words: Insulin helps convert glucose to glycogen, reducing blood sugar, whereas glucagon converts glycogen back to glucose, raising blood sugar.

🎯 Exam Tip: Remember the antagonistic roles of insulin and glucagon in maintaining blood glucose homeostasis.

Question 9. Secondary sexual characters in males : Testosterone :: Secondary sexual characters in females :
Answer: Oestrogen
In simple words: Testosterone is responsible for male secondary sexual characteristics, while oestrogen is responsible for female secondary sexual characteristics.

🎯 Exam Tip: Know the primary sex hormones in males and females and their roles in developing secondary sexual characteristics.

Match the columns:

Question 1.
Column 'A'
(1) Gibberellins
(2) Cytokinins
(3) Abscisic acid
(4) Auxin
Column 'B'
(a) Enlargement of cells
(b) Helps in stem elongation
(c) Cell division
(d) Wilting of leaf
Answer:
(1 - b),
(2 - c),
(3 - d),
(4 - a).
In simple words: This matching exercise connects plant hormones to their specific functions, such as gibberellins for stem elongation, cytokinins for cell division, abscisic acid for leaf wilting, and auxin for cell enlargement.

🎯 Exam Tip: A clear understanding of each plant hormone's primary function is essential for matching type questions.

State whether the following statements are true or false. Correct the false statements.

Question 1. Plants need less energy as compared to animals.
Answer: True
In simple words: Plants, being autotrophic and generally stationary, have lower metabolic rates and thus require less energy than mobile, heterotrophic animals.

🎯 Exam Tip: Relate the energy requirements of organisms to their metabolic activity and lifestyle (e.g., autotrophic vs. heterotrophic, sessile vs. motile).

Question 2. Xylem conducts food whereas phloem conducts water.
Answer: False. Xylem conducts water whereas phloem conducts food.
In simple words: Xylem is the plant tissue responsible for transporting water, while phloem transports food throughout the plant.

🎯 Exam Tip: Clearly differentiate the roles of xylem and phloem; a common misconception is to swap their functions.

Question 3. The loss of water from the plants is known as translocation.
Answer: False. The loss of water from the plants is known as transpiration.
In simple words: Transpiration is the process of water vapor release from plant leaves, whereas translocation refers to the movement of food.

🎯 Exam Tip: Use precise terminology for plant processes; transpiration involves water loss, while translocation involves nutrient transport.

Question 4. Calcium oxalate crystals present in some plants are called resins.
Answer: False. Calcium oxalate crystals present in some plants are called raphides.
In simple words: Calcium oxalate crystals in plants are specifically known as raphides, not resins. Resins are different plant excretions.

🎯 Exam Tip: Be specific with the names of plant excretory products and their chemical composition.

Question 5. Root pressure helps to push the water up in plants during night time.
Answer: True
In simple words: Root pressure is most effective in pushing water up the xylem at night when transpiration rates are low, helping to maintain a continuous water column.

🎯 Exam Tip: Remember that root pressure is a significant force for water transport especially when transpiration pull is minimal.

Question 6. Translocation is carried out by phloem in downward direction.
Answer: False. Translocation is carried out by phloem in both upward and downward direction.
In simple words: Phloem transports food (translocation) not just downwards, but also upwards and sideways to meet the metabolic needs of all plant parts.

🎯 Exam Tip: Translocation is a bidirectional process, moving sugars from source to sink, which can be in any direction relative to gravity.

Question 7. In unicellular organisms, waste materials are directly eliminated across the cell surface.
Answer: True
In simple words: Unicellular organisms, due to their simple structure and high surface area-to-volume ratio, can excrete waste directly through their cell membrane via diffusion.

🎯 Exam Tip: Understand that simple organisms rely on basic processes like diffusion for excretion due to their lack of complex organ systems.

Question 8. Urea is produced in the liver.
Answer: True
In simple words: In humans, the liver converts toxic ammonia into less harmful urea, which is then transported to the kidneys for excretion.

🎯 Exam Tip: The liver's role in the urea cycle is a key concept in human metabolism and waste management.

Question 9. Systematic regulation of different processes is called co-ordination.
Answer: False. Systematic regulation of different processes is called control.
In simple words: Control refers to the systematic regulation of processes, while coordination involves bringing these processes into proper sequence.

🎯 Exam Tip: Differentiate between "control" (regulating individual processes) and "co-ordination" (sequencing multiple processes for a collective outcome).

Question 10. A hormone auxin produced in the apical part of the shoot helps in enlargement of cells.
Answer: True
In simple words: Auxin, produced at the shoot tip, promotes cell elongation, contributing to plant growth.

🎯 Exam Tip: Remember that auxin is a primary plant growth hormone, specifically promoting cell enlargement.

Question 11. Gibberellin helps in prevention and retardation of growth, leaf wilting etc.
Answer: False. Abscisic acid helps in prevention and retardation of growth, leaf wilting etc.
In simple words: Abscisic acid, not gibberellin, is the plant hormone responsible for inhibiting growth and causing phenomena like leaf wilting.

🎯 Exam Tip: Distinguish between growth-promoting hormones (like gibberellin) and growth-inhibiting hormones (like abscisic acid).

Question 12. The movement shown by venus fly trap while trapping an insect is a growth relevant movement.
Answer: False. The movement shown by venus fly trap while trapping an insect is a growth irrelevant movement.
In simple words: The rapid closure of a Venus flytrap is a quick, turgor-driven movement for trapping prey, not a slow, irreversible growth-related movement.

🎯 Exam Tip: Classify plant movements into growth-relevant (tropisms) and growth-irrelevant (nastic movements, turgor changes) categories.

Question 13. The lotus flower opens during night time while that of tuberose (polyanthus) opens during day time.
Answer: False. The lotus flower opens during day time while that of tuberose (polyanthus) opens during night time.
In simple words: Lotus flowers exhibit nyctinasty by opening during the day, whereas tuberose flowers open at night.

🎯 Exam Tip: Be aware of examples of nyctinastic movements (sleep movements) in plants and their timing.

Question 14. Sensory neurons conduct impulses from the brain and the spinal cord to effector organs like muscles or glands.
Answer: False. Sensory neurons conduct impulses from the sensory organs to the brain and the spinal cord.
In simple words: Sensory neurons carry signals *to* the central nervous system from sensory organs, while motor neurons carry signals *from* the CNS to effector organs.

🎯 Exam Tip: Correctly identify the direction of impulse transmission for sensory and motor neurons in the nervous system.

Question 15. There are 31 pairs of cranial nerves.
Answer: False. There are 12 pairs of cranial nerves.
In simple words: Humans have 12 pairs of cranial nerves, not 31. The 31 pairs refer to spinal nerves.

🎯 Exam Tip: Memorize the number of pairs of cranial and spinal nerves in humans.

Question 16. Activities like heart beat, blood circulation, breathing, sneezing, etc. are controlled by cerebellum.
Answer: False. Activities like heart beat, blood circulation, breathing, sneezing, etc. are controlled by medulla oblongata.
In simple words: Involuntary vital functions such as heartbeat, breathing, and blood circulation are regulated by the medulla oblongata, not the cerebellum.

🎯 Exam Tip: Understand the specific roles of different brain regions, particularly the medulla oblongata for vital involuntary functions.

Question 17. Spinal nerves are associated with head, thorax and abdomen.
Answer: False. Spinal nerves are associated with arms, legs, skin and some other parts of the body.
In simple words: Spinal nerves connect to the limbs and torso, while cranial nerves are associated with the head, neck, and some internal organs in the thorax and abdomen.

🎯 Exam Tip: Distinguish the distribution and innervation patterns of spinal nerves versus cranial nerves.

Question 18. Nerve impulses are slow and long lasting whereas action of hormones is fast and short lived.
Answer: False. Nerve impulses are fast and short lived whereas action of hormones is slow and long lasting.
In simple words: Nerve impulses provide rapid, short-term responses, while hormonal actions are typically slower to initiate but have long-lasting effects.

🎯 Exam Tip: Compare and contrast the characteristics of nervous and hormonal control, focusing on speed and duration of action.

Question 19. Reflex actions are controlled by cerebellum.
Answer: False. Reflex actions are controlled by spinal cord.
In simple words: Reflex actions are involuntary responses primarily coordinated at the level of the spinal cord, bypassing the brain for immediate reaction.

🎯 Exam Tip: Identify the spinal cord as the primary center for coordinating reflex actions, demonstrating its role in rapid responses.

Question 20. Thyroid stimulating hormone is secreted by the pituitary gland.
Answer: True
In simple words: The pituitary gland secretes Thyroid Stimulating Hormone (TSH), which then prompts the thyroid gland to produce thyroid hormones.

🎯 Exam Tip: Understand the role of the pituitary gland as the "master gland" and its control over other endocrine glands.

Question 21. The hormone thymosin is secreted by the thyroid gland.
Answer: False. The hormone thymosin is secreted by the thymus gland.
In simple words: Thymosin is produced by the thymus gland, not the thyroid gland, and is crucial for immune system development.

🎯 Exam Tip: Accurately link hormones to their respective endocrine glands to avoid common confusions.

Question 22. Parathormone controls metabolism of calcium and phosphorns.
Answer: True
In simple words: Parathormone, secreted by the parathyroid glands, plays a vital role in regulating calcium and phosphorus levels in the blood and bones.

🎯 Exam Tip: Recognize parathormone's specific function in calcium and phosphorus homeostasis.

Question 23. The right kidney is slightly lower than the left kidney.
Answer: True
In simple words: Due to the presence of the liver above it, the right kidney is positioned slightly lower in the abdominal cavity compared to the left kidney.

🎯 Exam Tip: Understand the anatomical positioning of organs and the reasons behind slight variations (e.g., liver's location affecting kidney position).

Name The Following:

Question 1. The structural and functional unit of the nervous system.
Answer: Neuron.
In simple words: Neurons are the fundamental building blocks of the nervous system, responsible for transmitting electrical and chemical signals.

🎯 Exam Tip: Define neurons as the basic unit of the nervous system, similar to how cells are the basic unit of life.

Question 2. The network of capillaries in the Bowman's capsule.
Answer: Glomerulus.
In simple words: The glomerulus is a tiny ball of capillaries within the Bowman's capsule where the filtration of blood begins in the kidney.

🎯 Exam Tip: Identify the glomerulus as the key site for initial blood filtration in the nephron.

Question 3. The minute space between two adjacent nervous.
Answer: Synapse.
In simple words: A synapse is the small gap between two neurons or between a neuron and an effector cell, across which nerve impulses are transmitted.

🎯 Exam Tip: The synapse is critical for communication between nerve cells and for complex nervous system functions.

Question 4. The special cells which bring about control and co-ordination.
Answer: Neurons.
In simple words: Neurons are specialized cells that transmit information, enabling control and coordination throughout the body's nervous system.

🎯 Exam Tip: Reiterate the role of neurons as the primary cells for communication and regulation in the nervous system.

Question 5. The cavities present in various parts of the brain.
Answer: Ventricles.
In simple words: The brain contains fluid-filled spaces called ventricles that produce and circulate cerebrospinal fluid, protecting the brain.

🎯 Exam Tip: Know the term "ventricles" for the brain's internal cavities and their protective function.

Question 6. The long tubular cavity of the spinal cord.
Answer: Central Canal.
In simple words: The central canal is a narrow, fluid-filled channel that runs through the center of the spinal cord, containing cerebrospinal fluid.

🎯 Exam Tip: The central canal is an important anatomical feature of the spinal cord, continuous with the brain's ventricular system.

Question 7. The thread like fibrous structure at the end of the spinal cord.
Answer: Filum terminale.
In simple words: The filum terminale is a thin, fibrous extension that anchors the spinal cord to the coccyx.

🎯 Exam Tip: Identify the filum terminale as the stabilizing structure at the caudal end of the spinal cord.

Give Scientific Reasons:

Question 1. It is necessary to remove harmful and waste substances from the body.
Answer:
• Many harmful and waste substances like urea, uric acid, ammonia, etc. are produced in living organisms.
• If these substances accumulate in the body or are retained in the body for long, it can lead to serious harm or even death.
• Hence, it is necessary to remove such harmful and waste substances from the body.
In simple words: Waste products are toxic if they build up, so the body must remove them to prevent illness and maintain proper function.

🎯 Exam Tip: Emphasize the toxicity of metabolic wastes and the critical role of excretion in maintaining homeostasis and survival.

Question 2. In plants like Touch-me-not (Mimosa), movement also occurs at the places other than where it has been touched.
Answer:
• In plants like Touch-me-not (Mimosa), the information about the touch is relayed within the plant from one place to another.
• Plants use electro-chemical impulses for transfer of information from one place to another.
• Plant cells change their shape by increasing or decreasing their water content and thereby, bring about the movements of plants.
• Hence, in plants like Touch-me-not (Mimosa) movement also occurs at the places other than where it has been touched.
In simple words: The touch-me-not plant transmits electrochemical signals throughout its leaves, causing cells to lose water and fold up even in untouched areas, demonstrating internal communication.

🎯 Exam Tip: Understand that plant movements, even rapid ones, involve internal communication and turgor pressure changes, not just direct contact response.

Question 3. Endocrine glands are also called ductless glands.
Answer:
• Hormones are secreted by endocrine glands.
• These glands do not have any arrangement of their own to store or carry their secretions.
• Hence, as soon as hormones are produced, they are directly released into the blood circulation.
• Thus, though these endocrine glands are present at specific locations in our body, their secretions reach all parts of the body via blood.
• Therefore, endocrine glands are also called ductless glands.
In simple words: Endocrine glands release hormones directly into the bloodstream because they lack ducts, allowing the hormones to travel throughout the body to target cells.

🎯 Exam Tip: The absence of ducts and direct release into blood define endocrine glands, contrasting them with exocrine glands which have ducts.

Define The Following:

Question 1. Transportation
Answer: The process by which a substance either synthesized or absorbed in one part of the body reaches another is called as transportation.
In simple words: Transportation is the movement of materials from one part of an organism to another.

🎯 Exam Tip: Transportation is a vital life process ensuring nutrients, water, and gases are distributed throughout an organism.

Question 2. Control
Answer: Systematic regulation of different processes is called as control.
In simple words: Control is the organized regulation of various biological processes to maintain proper function.

🎯 Exam Tip: Control ensures that individual biological activities occur effectively and according to specific parameters.

Question 3. Coordination
Answer: Bringing about the different processes in the proper sequence is called as co-ordination.
In simple words: Coordination is the harmonious and sequential organization of different processes to achieve a specific function or outcome.

🎯 Exam Tip: Coordination ensures that multiple processes work together smoothly and in the correct order for an organism's overall well-being.

Question 4. Tropism or Tropic movement
Answer: Movement or growth of any part of the plant in response to an external stimulus is called as tropism or tropic movement.
In simple words: Tropism is a plant's growth response, either towards or away from an external stimulus like light or gravity.

🎯 Exam Tip: Tropisms are crucial for plant survival, helping them orient towards favorable conditions for growth and resource acquisition.

Question 5. Excretion
Answer: Removal of waste or harmful substances from the body is called excretion.
In simple words: Excretion is the process by which living organisms eliminate metabolic waste products from their bodies.

🎯 Exam Tip: Excretion is essential for maintaining internal balance by removing toxic by-products of metabolism.

Question 6. Dialysis
Answer: The process of separating the nitrogenous waste from the blood with the help of a man-made machine is called dialysis.
In simple words: Dialysis is an artificial medical procedure that filters waste products from the blood when the kidneys fail.

🎯 Exam Tip: Dialysis mimics the kidney's function of removing waste, vital for patients with kidney failure.

Question 7. Reflex action
Answer: An immediate and involuntary response given to a stimulus from the environment is called a reflex action.
In simple words: A reflex action is a quick, automatic bodily response to a stimulus that doesn't involve conscious thought.

🎯 Exam Tip: Reflex actions are protective mechanisms that allow for rapid responses to potentially harmful stimuli.

Question 8. Homeostasis
Answer: Proper co-ordination between various systems of an organism helps to maintain a state of equilibrium called homeostasis.
In simple words: Homeostasis is the ability of an organism to maintain stable internal conditions despite external changes.

🎯 Exam Tip: Homeostasis is a fundamental concept in biology, highlighting the body's dynamic self-regulation to ensure optimal functioning.

Question 9. Tropism
Answer: Movement or growth of any part of the plant in response to an external stimulus is called tropism.
In simple words: Tropism is a directed growth movement of a plant in response to an external cue, such as light or gravity.

🎯 Exam Tip: Tropisms are essential for plants to optimize their access to resources like sunlight and water.

Distinguish Between:

Question 1. Nervous control and Chemical control
Answer:

🎯 Exam Tip: Focus on the speed, duration, type of messenger, and systems involved to clearly differentiate nervous and chemical control.

Question 2. Growth relevant movements and growth irrelevant movements
Answer:

🎯 Exam Tip: The key distinction lies in whether the movement involves irreversible growth (tropic) or temporary, reversible changes (nastic).

Question 3. Cerebrum and Cerebellum
Answer:

🎯 Exam Tip: Focus on the size, location, surface features, and primary functions to distinguish the cerebrum from the cerebellum effectively.

Write Short Notes:

Question 1. Root Pressure
Answer:
• Root cells are in contact with water and minerals in the soil.
• Water and minerals enter the cells of the root surface due to difference in concentration. As a result, these cells become turgid.
• This is called root pressure.
• Under the effect of this pressure, water and minerals reach the xylem of the roots and to reduce this difference in concentration, they are continuously pushed forward.
• As a result of this continuous movement, a water column is formed, which is continuously pushed ahead.
• This pressure, is sufficient to lift the water up in shrubs, small plants and small trees.
In simple words: Root pressure is the upward push of water in plant xylem, generated by the active absorption of water and minerals by root cells, especially important for water transport in smaller plants at night.

🎯 Exam Tip: Highlight that root pressure is generated by active absorption in roots and is significant for water transport in smaller plants or at night.

Question 2. Transpiration
Answer:
• Plants give out water in the form of water vapour through the stomata on their leaves. This is known as transpiration.
• Two cells called guard cells are present around the stomata. They control the opening and closing of stomata.
• Water is released into the atmosphere by leaves through the process of evaporation.
• As a result, water in the epidermal layer of the leaf decreases.
• Water is brought up to the leaves through the xylem to compensate for the lost water.
• Transpiration helps in absorption of water and minerals and distribution to all parts of the plant.
In simple words: Transpiration is the process where plants release water vapor from their leaves into the atmosphere, which creates a pull that helps draw water and minerals from the roots up to the leaves.

🎯 Exam Tip: Emphasize that transpiration is driven by water loss from stomata and is a major force for water and mineral transport in plants.

Question 3. Nerve cell
Answer:
• Nerve cells also called as neurons are special types of cells which conduct impulses from one place to another in the body.
• Neurons are the structural and functional units of the nervous system.
• Nerve cells, the largest cell in the human body, may measure upto a few metres in length.
• Nerve cells have the ability to generate and conduct electrochemical impulse.
• The cells that support the nerve cells and help in their functioning are called neuroglia. Nerve cells and neuroglial cells together form nerves.
In simple words: Nerve cells, or neurons, are specialized cells that transmit electrochemical impulses throughout the body, forming the fundamental units of the nervous system.

🎯 Exam Tip: Define neurons as the basic units of the nervous system capable of generating and conducting electrochemical signals.

Question 4. Reflex action
Answer:
• An immediate and involuntary response given to a stimulus from the environment is called a reflex action.
• Sometimes we react to an incident without any thinking on our part or control over the reaction.
• This is a response given to a certain stimulus from the surroundings.
• In such situations, proper control and co-ordination is achieved even without the intervention of the brain.
• For example, when our hand touches a hot object, the receptor in the skin detects the stimulus.
• The sensory neuron sends the impulse to the relay neuron in the spinal cord.
• The impulses are then sent to motor neurons which cause the muscles of the hand to contract and move away from the hot object.
• The spinal cord is the center of co-ordination for reflex actions.
In simple words: A reflex action is a rapid, automatic, and involuntary response to a stimulus, often coordinated by the spinal cord without direct brain involvement, serving as a protective mechanism.

🎯 Exam Tip: Clearly explain the involuntary nature, rapid response, and spinal cord's role in reflex actions, providing an example.

Question 5. Spinal cord
Answer:
• The spinal cord is the part of the central nervous system and it is held within the vertebral column.
• It is slightly thick but gradually tapers towards the end.
• There is a thread like fibrous structure at its end. It is called the filum terminale.
• The long tubular cavity of the spinal cord is called the central canal. It is filled with cerebrospinal fluid.
• The spinal cord conducts impulses from the skin towards the brain and from the brain to the muscles and glands.
• It functions as a centre of co-ordination of reflex actions.
In simple words: The spinal cord is a vital part of the central nervous system, protected by the vertebral column, that conducts nerve impulses between the brain and the body, and acts as the center for reflex actions.

🎯 Exam Tip: Describe the spinal cord's location, protective covering, internal structure (central canal), and dual function as a relay pathway and reflex center.

Question 6. Dialysis
Answer:
• The efficiency of kidneys can be adversely affected by injury, infection or decreased blood supply.
• If this happens, excess of toxic substances accumulates in the body and it can lead to death.
• If kidneys fail, nitrogenous wastes are separated from the blood with the help of a man-made machine.
• The process of separating the nitrogenous waste from the blood with the help of this machine is called dialysis.
• About 500 ml of blood is sent at one time through this machine. Purified blood is reinfused into the body of the patient.
In simple words: Dialysis is an artificial medical procedure that filters toxic waste products from the blood using a machine, essential when the kidneys are unable to perform this vital function.

🎯 Exam Tip: Explain dialysis as an artificial kidney function, detailing its purpose of removing nitrogenous wastes and the process of blood filtration and reinfusion.

Draw Neat And Labelled Diagrams:

Question 1. Vertical Section of Kidney
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव किडनी के लंबवत अनुप्रस्थ काट को दर्शाता है, जिसमें गुर्दे की कैप्सूल, कॉर्टेक्स, रीनल पिरामिड, रीनल धमनी, रीनल शिरा, यूरेटर और रीनल कैलिक्स जैसे प्रमुख आंतरिक संरचनाएं स्पष्ट रूप से नामांकित हैं। यह किडनी की आंतरिक संरचना और उसके विभिन्न भागों के संगठन को समझने में मदद करता है।
In simple words: This diagram shows the internal structure of a human kidney, labeling key parts like the capsule, cortex, medulla (pyramids), blood vessels, and ureter. It helps visualize how the kidney is organized to filter blood.

🎯 Exam Tip: Accurately labeling all parts of the kidney's vertical section is crucial for full marks. Ensure clear, legible labels and correct anatomical placement.

Question 2. Reflex action
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र एक प्रतिवर्ती क्रिया (रिफ्लेक्स एक्शन) का वर्णन करता है, जिसमें त्वचा पर एक उत्तेजना (जैसे गर्मी) से लेकर संवेदी न्यूरॉन, एसोसिएशन न्यूरॉन और मोटर न्यूरॉन के माध्यम से मांसपेशियों की प्रतिक्रिया तक के मार्ग को दिखाया गया है। इसमें रिसेप्टर, रीढ़ की हड्डी और कार्य करने वाली मांसपेशियां शामिल हैं।
In simple words: This diagram illustrates a reflex action, showing how a stimulus is detected by a receptor, transmitted through sensory, association, and motor neurons, leading to an immediate muscle response without conscious brain involvement. It demonstrates the neural pathway for quick, involuntary actions.

🎯 Exam Tip: When drawing a reflex action, clearly differentiate between sensory and motor neurons and show the path through the spinal cord. Highlighting the receptor and effector organ is key.

Name The Hormones Of The Following Endocrine Glands And The Function Of Each:

Question 1. Parathyroid
Answer:

🎯 Exam Tip: Remember that parathormone specifically targets calcium and phosphorus balance, which is vital for bone integrity and various cellular processes.

Question 2. Pancreas
Answer:

🎯 Exam Tip: For the pancreas, focus on the antagonistic roles of insulin (lowers blood glucose) and glucagon (raises blood glucose) and their importance in metabolic regulation.

Complete The Following Table Of Plant Hormones With Their Functions:

Answer:

🎯 Exam Tip: Understand that plant hormones (phytohormones) have specific roles; knowing which hormone performs which function (e.g., Auxin for cell enlargement, Gibberellins for stem elongation) is key.

State The Functions Of Different Parts Of The Brain.

Answer:

🎯 Exam Tip: When listing brain functions, categorize them clearly by part (Cerebrum, Cerebellum, Medulla oblongata, Spinal cord) and distinguish between voluntary and involuntary actions, as well as coordination and sensory/motor roles.

Answer The Following:

Question 1. How do plants bring about movements in them?
Answer:
• Plants use electro-chemical impulses for transfer of information from one place to another.
• Plant cells change their shape by increasing or decreasing their water content and thereby bring about the movement of plants.
In simple words: Plants move by using electrochemical signals to communicate information internally and by changing the water content within their cells, which alters cell shape and leads to visible movements.

🎯 Exam Tip: Focus on the two main mechanisms: electrochemical impulses for signal transmission and changes in turgor pressure (water content) for physical movement.

Question 1. What are growth-irrelevant movements? Give examples.
Answer:
• Some specific movements of the plants do not lead to the plant growth. Such movements are called growth-irrelevant movements.
• In the plant called venus fly trap, there is a trap that appears and smells like flowers and deceives insects. When an insect visits the flower-like trap, the trap closes up and the trapped insect is digested by the plant.
• Fibrils present on the leaves of the insectivorous plant Drosera, bend inward as soon as an insect lands on the leaves and surround the insects from all sides.
• In Balsam, the ripened fruit dehisces (bursts-open) at the right time to disperse the seeds.
In simple words: Growth-irrelevant movements in plants are quick, temporary changes in shape or position that are not related to overall growth, such as the rapid closing of a Venus fly trap to catch prey or the bursting of a balsam fruit to scatter seeds.

🎯 Exam Tip: Emphasize that these movements are typically rapid responses to stimuli and are not a result of cell division or enlargement, providing clear examples like Venus fly trap or Mimosa.

Question 2. Which are the different types of nerve cells or neurons? OR How are nerve cells classified according to their functions?
Answer:According to their functions, nerve cells are classified into three types:
• Sensory neurons: They conduct impulses from the sensory organs to the brain and the spinal cord.
• Motor neurons : They conduct impulses from the brain or spinal cord to effector organs like muscles or glands.
• Association neurons : Association neurons perform the function of integration in the nervous system.
In simple words: Nerve cells, or neurons, are specialized for transmitting information and are categorized by their role: sensory neurons carry signals to the brain, motor neurons carry signals from the brain to muscles, and association neurons link and process information between other neurons.

🎯 Exam Tip: For neurons, distinguish clearly between the three types based on the direction of impulse transmission and their primary function (sensing, acting, or processing).

Question 3. What are the different parts of the human nervous system?
Answer:The human nervous system can be divided into the following three parts.
1. Central nervous system (CNS) : It consists of the brain and the spinal cord. It controls and regulates all activities of the body.
2. Peripheral nervous system (PNS) : The peripheral nervous system consists of the nerves originating from the central nervous system which connect the central nervous system with all parts of the body. They are of two types cranial nerves and spinal nerves.
3. Autonomic nervous system (ANS) : The autonomous nervous system consists of the nerves of involuntary organs like the heart, lungs, stomach etc. It is not under the control of our will.
In simple words: The human nervous system is divided into three main parts: the Central Nervous System (brain and spinal cord) which is the control center, the Peripheral Nervous System (nerves extending throughout the body) which connects the CNS to limbs and organs, and the Autonomic Nervous System which controls involuntary bodily functions.

🎯 Exam Tip: Clearly define each of the three main divisions (CNS, PNS, ANS) and list their key components and primary functions to demonstrate a comprehensive understanding.

Question 4. Describe the structure of the central nervous system.
Answer:
• The central nervous system consists of the brain and spinal card.
• The organization of the brain is extremely delicate and highly evolved.
• The brain is the main controlling part of the nervous system and is safely located in the cranial cavity. The spinal cord is protected by the vertebral column.
• In the space between the delicate central nervous system and its bony covering are the protective layers called the meninges.
• Cavities present in various parts of the brain are called ventricles whereas the long tubular cavity of the spinal cord is called the central canal.
• The ventricles, central canal and spaces between the meninges are filled with cerebro-spinal fluid.
• This fluid supplies nutrients to the central nervous system and protects it from shock.
In simple words: The Central Nervous System (CNS) includes the brain and spinal cord, both housed within bony protections (cranium and vertebral column) and further cushioned by meninges and cerebrospinal fluid. These structures contain cavities filled with cerebrospinal fluid, which provides nutrients and shock absorption.

🎯 Exam Tip: When describing the CNS structure, remember to mention both its components (brain, spinal cord) and its protective elements (bones, meninges, cerebrospinal fluid) for a complete answer.

Question 5. Which are the two types of peripheral nerves?
Answer:Peripheral nerves are of two types:
(a) Cranial nerves:
• Nerves originating from the brain are called cranial nerves.
• They are associated with various parts in the head.
• There are 12 pairs of cranial nerves.
(b) Spinal nerves:
• Nerves originating from the spinal cord are called spinal nerves.
• They are associated with arms, legs, skin and some other parts of the body.
• There are 31 pairs of spinal nerves.
In simple words: The two types of peripheral nerves are cranial nerves, which originate from the brain and primarily serve the head region, and spinal nerves, which emerge from the spinal cord and connect to the rest of the body.

🎯 Exam Tip: Differentiate cranial and spinal nerves by their origin (brain vs. spinal cord) and approximate number of pairs (12 vs. 31), as well as their general distribution in the body.

Question 6. How do plants get rid of their excretory products?
Answer:
• Excretion is a simpler process in plants. There is no special organ or system for excretion in plants.
• Gases are given out by diffusion.
• Most of the waste substances of plants are stored in vacuoles of leaf-cells and in flowers, fruits and the bark of the stem. After some time these parts fall off.
• Some other waste materials are stored in old and worn out xylem in the form of resin and gum.
• Some waste materials are also given out through roots in the surrounding soil.
In simple words: Plants excrete waste simply: gases are diffused out, solid wastes are stored in vacuoles of leaves, flowers, fruits, or bark which are eventually shed, or in old xylem as resins and gums, and some wastes are released into the soil through roots.

🎯 Exam Tip: Focus on the various passive methods plants use for excretion, highlighting the absence of specialized excretory organs and the role of shedding parts, storage, and diffusion.

Answer In Detail:

Question 1. Explain how food and other substances are transported in plants? OR Explain translocation in plants.
Answer:
• The food produced in leaves is transported to each cell in the plant body.
• Excess food, except amino acids, is stored in roots, fruits and seeds. This process is called translocation of materials.
• It is carried out in both the upward and downward directions by the phloem.
• Translocation is not a simple process, it requires energy. This energy is obtained from ATP.
• Whenever food material like sucrose is transported towards a part of a plant via the phloem with the help of ATP, the water concentration decreases in the part. As a result, water enters the cell by the process of diffusion.
• The pressure on the cell wall increases due to increase in cellular contents.
• Due to the increase pressure, food is pushed into the neighbouring cells where the pressure is low.
• This process helps the phloem to transport the materials as per the need of the plant. During flowering season, the sugar stored in roots or stem is transported towards the floral buds to make them open and blossom.
In simple words: Translocation is how plants move food, mainly sucrose, from leaves to other parts using the phloem tissue. This active process requires ATP, creating pressure gradients that push food to areas of lower pressure, supporting growth and development throughout the plant.

🎯 Exam Tip: Explain translocation as an energy-dependent process occurring in phloem, highlighting the role of ATP, pressure gradients, and the bidirectional movement of food materials from source to sink.

Question 2. What is tropic movement? Describe the different types of tropic movements. OR What are growth relevant movements? Describe the different types of growth relevant movements.
Answer:Movement or growth of any part of the plant in response to an external stimulus is called tropic movement or tropism. The different types of tropic movements are:
• Phototropic movement : The shoot system of any plant responds to the light stimulus, i.e., it grows towards the source of light. The movement shown by plants towards the source of light is called phototropic movement.
• Gravitropic movement : The root system of plants responds to stimulus of gravity. This is called gravitropic movement.
• Hydrotropic movement : The root system of plants responds to the stimulus of water. This is called hydrotropic movement.
• Chemotropic movement : Movement shown by plants in response to specific chemicals is called chemotropic movement. For example, the growth of the pollen tube towards the ovule. All the above-mentioned movements of plants are related with growth, hence are called growth relevant movement.
In simple words: Tropic movements, or tropisms, are growth-related plant movements in response to external stimuli. Examples include phototropism (growing towards light), gravitropism (roots growing downwards due to gravity), hydrotropism (roots growing towards water), and chemotropism (pollen tubes growing towards specific chemicals).

🎯 Exam Tip: Define tropism clearly and provide specific examples for each type (photo, gravi, hydro, chemo), explaining the stimulus and the plant part's response. Emphasize that these are growth-related.

Question 3. Write short note on : Human Brain
Answer:
• The brain is the main controlling part of the nervous system and is safely located in the cranial cavity.
• The brain is covered by protective layers called the Meninges.
• Cavities present in various parts of the brain are called ventricles.
• The ventricles are filled with cerebrospinal fluid. This fluid supplies nutrients to the brain and also protects it from shock.
• The brain of an adult human weighs about 1300 -1400 grams and consists of approximately 100 million neurons.
• The left side of our brain controls the right side of our body and right side of our brain controls left side of the body.
• In addition, the left side of the brain controls our speech and conversation, writing, logical thinking etc., whereas the right side controls artistic abilities. Human brain is made up of following parts:
(a) Cerebrum:
• This is the largest part of the brain and consists of two cerebral hemispheres. These hemispheres are joined with each other with the help of tough fibres and nerve tracts.
• The cerebrum occupies two-thirds of the brain. Hence, it is also called as large brain.
• Its surface has deep, irregular ridges and grooves which are called convolutions, convolution increases the surface area of the cerebrum and therefore a large number of nerve cells can be accommodated.
(b) Cerebellum:
• This is the smaller part of the brain situated below the cerebrum at the back of the cranial cavity.
• Its surface shows shallow grooves instead of deep convolutions.
(c) Medulla Oblongata:
• This is the hind-most part of the brain.
• There are two triangular swollen structures called pyramids on the upper side of medulla oblongata.
• The medulla oblongata continues downwards the spinal cord.
In simple words: The human brain, a complex organ weighing 1300-1400 grams and containing millions of neurons, is protected by the skull, meninges, and cerebrospinal fluid. It's divided into the cerebrum (for higher functions), cerebellum (for coordination), and medulla oblongata (for vital involuntary actions), with each hemisphere controlling the opposite side of the body.

🎯 Exam Tip: A good short note on the human brain should cover its protective coverings, fluid, weight, the three main parts (cerebrum, cerebellum, medulla oblongata), and a key function for each part.

Question 6. How are nerve impulses conducted in the body?
Answer:
• Special types of cells which conduct impulses from one place to another in the body are called neurons. Nerve cells have the ability to generate and conduct electro-chemical impulses.
• The cells that support the nerve cells and help in their functioning are called neuroglia.
• All the information about our surroundings is collected by the ends or dendrites of the neuron.
• The chemical process begins at those ends and electric impulses are generated which are conducted from the dendrites to the cell body, from the cell body to the axon and from the axon to its terminal.
• These impulses are then to be transferred from this nerve cell to the next.
• Now the impulse that reaches the terminal of an axon, stimulates the nerve cell to secrete certain chemicals.
• These chemicals pass through a minute space, called the synapse, between two adjacent neurons and generate the impulses in the dendrites of the next neuron.
• In this way, impulses are conducted in the body and these impulses are finally conveyed by nerve cells to muscles cells or glands.
In simple words: Nerve impulses are electrochemical signals transmitted by neurons. They begin at dendrites, travel through the cell body and axon, and cross a synapse to the next neuron using chemical neurotransmitters, ultimately reaching target muscles or glands to evoke a response.

🎯 Exam Tip: Describe the pathway of a nerve impulse clearly, mentioning dendrites, cell body, axon, and especially the role of synapse and neurotransmitters in transmitting the impulse between neurons.