Maharashtra Board Class 6 Science Chapter 8 Our Skeletal System and the Skin Solutions

Std 6 Science Chapter 8 Our Skeletal System And The Skin Question Answer Maharashtra Board

Class 6 Science Chapter 8 Our Skeletal System And The Skin Question Answer Maharashtra Board

1. Fill In The Blanks With The Proper Word.

Question a. The place where two or more bones are connected is called a ............... .
Answer: joint
In simple words: A joint is a point where two or more bones meet, allowing movement or providing stability to the skeletal system.

🎯 Exam Tip: Understanding the definition of a joint is fundamental to understanding skeletal movement.

Question b. Cells of epidermis contain a pigment called ............... .
Answer: melanin
In simple words: Melanin is the pigment found in epidermal cells that determines skin and hair color and offers protection against UV radiation.

🎯 Exam Tip: Knowing the role of melanin is important for understanding skin color and sun protection.

Question c. ............... and ............... are the two layers of the human skin.
Answer: epidermis, dermis
In simple words: The human skin consists of two primary layers: the outer epidermis and the inner dermis, each with distinct functions.

🎯 Exam Tip: Identifying the main layers of the skin is crucial for understanding its basic structure and function.

Question d. The human skeletal system is divided into ......... parts.
Answer: two
In simple words: The human skeletal system is broadly categorized into two main parts: the axial skeleton and the appendicular skeleton.

🎯 Exam Tip: Remembering the number of main divisions of the human skeletal system is a key factual detail.

2. Match The Pairs.

Question a. Match the following joints:

🎯 Exam Tip: Correctly identifying examples for each type of joint is essential for scoring well in anatomy questions.

3. Right Or Wrong? If Wrong, Write The Correct Sentence.

Question a. Bones are soft.
Answer: Wrong: Bones are hard.
In simple words: Bones are primarily hard and rigid structures, providing support and protection to the body, contrary to being soft.

🎯 Exam Tip: A clear understanding of bone properties, like hardness, is fundamental for basic biology.

Question b. The human skeleton protects the internal organs.
Answer: Right
In simple words: The human skeleton acts as a protective cage, shielding vital internal organs such as the brain, heart, and lungs from external injury.

🎯 Exam Tip: Recognizing the protective function of the skeleton is a key concept in understanding its importance.

4. Put A [√] Mark At The Proper Places.

Question a. The system which gives our body a definite shape.
(a) Excretory system []
(b) Respiratory system []
(c) Skeletal system []
(d) Circulatory system []
Answer: (c) Skeletal system
In simple words: The skeletal system provides the framework that gives the human body its characteristic shape and structure.

🎯 Exam Tip: Knowing the primary role of the skeletal system in providing shape and support is crucial for multiple-choice questions.

Question b. The ............ joint is seen in fingers and toes.
(a) Hinge joint []
(b) Ball and socket joint []
(c) Immovable joint []
(d) Gliding joint []
Answer: (a) Hinge joint
In simple words: Hinge joints, like those in fingers and toes, allow movement primarily in one plane, similar to a door hinge.

🎯 Exam Tip: Identifying common examples of hinge joints helps reinforce the understanding of joint types and their locations.

5. Answer The Following Questions In Your Words.

Question a. What are the functions of your skin?
Answer: The functions of the skin are :
1. Protects the internal parts of the body like muscles, bones, organ systems etc.
2. Help to preserve the moisture in the body.
3. Synthesizing Vitamin D.
4. Regulates body temperature by releasing sweat.
5. Gives protection from heat and cold.
6. Functions as the sensory organ of touch
In simple words: The skin serves multiple vital functions including protection of internal organs, moisture retention, Vitamin D synthesis, temperature regulation, and acting as a sensory organ.

🎯 Exam Tip: Listing and explaining the various functions of the skin is a common descriptive question; ensure all key roles are mentioned.

Question b. What should you do to keep the bones strong and healthy?
Answer: To keep the bones strong and healthy:
1. We should include calcium and phosphorous rich food in our diet.
2. We also include vitamin D rich food in our diet.
3. We get these from milk, milk products, leafy vegetables, meat and exposure to sunlight.
4. We should exercise regularly.
In simple words: To maintain strong and healthy bones, it's essential to consume calcium and phosphorus-rich foods, ensure adequate Vitamin D intake through diet and sunlight exposure, and engage in regular physical exercise.

🎯 Exam Tip: Providing practical steps for bone health, including diet and lifestyle choices, demonstrates a comprehensive understanding.

Question c. What are the functions of human skeletal system?
Answer: The functions of human skeletal system are:
1. Gives a definite shape to the body.
2. Provides support to the body.
3. Protects the delicate organs inside the body.
In simple words: The human skeletal system provides the body's framework, offers structural support, and protects vital internal organs.

🎯 Exam Tip: Focus on the three main functions – shape, support, and protection – when describing the skeletal system's role.

Question d. Which are the various reasons due to which our bones might break?
Answer: The bones in our body might break due to:
1. Lack of calcium and phosphorous.
2. Due to fracture because of an accident or a fall.
3. Lack of proper nutrition.
4. Due to deficiency of Vitamin D.
In simple words: Bones can break due to insufficient intake of essential minerals like calcium and phosphorus, Vitamin D deficiency, inadequate nutrition, or physical trauma from accidents or falls.

🎯 Exam Tip: Listing both nutritional and physical causes of bone fractures shows a complete understanding of bone health and vulnerability.

Question e. What are the different types of bones? How many types are there? Give example of each.
Answer: There are four types of bones in our body:

🎯 Exam Tip: Clearly defining each bone type with a correct example is vital for descriptive answers on bone classification.

6. What Will Happen If?

Question a. There are no joints in our body.
Answer: If there are no joints in our body, we will be standing like a tree without any movement, we can move only because of joints.
In simple words: Without joints, our skeletal system would be a rigid, immovable structure, completely preventing any form of movement.

🎯 Exam Tip: Emphasize the critical role of joints in enabling movement when answering hypothetical scenarios.

Question b. There is no melanin pigment in our body.
Answer: We will not have protection from ultraviolet rays. Our skin will become whitish.
In simple words: Lacking melanin would result in a whitish skin tone and no natural protection against harmful ultraviolet rays, making the skin highly vulnerable to sun damage.

🎯 Exam Tip: Connect the absence of melanin directly to both physical appearance (skin color) and physiological function (UV protection).

Question c. Instead of 33 vertebras in our body, we had one single and straight bone.
Answer: We cannot bend down at our will.
In simple words: If the spine were a single straight bone instead of multiple vertebrae, we would lose all flexibility and be unable to bend or twist our torso.

🎯 Exam Tip: Highlight the importance of individual vertebrae and their flexible arrangement for the body's range of motion.

7. Draw Diagrams.

Question a. Types of joints.
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव शरीर में विभिन्न प्रकार के जोड़ों को दर्शाता है, जिसमें कब्ज़ा जोड़ (Hinge joint) जो एक ही दिशा में गति की अनुमति देता है जैसे कोहनी और घुटना, बॉल और सॉकेट जोड़ (Ball and socket joint) जो सभी दिशाओं में व्यापक गति प्रदान करता है जैसे कंधा और कूल्हा, और ग्लाइडिंग जोड़ (Gliding joint) जो हड्डियों को एक दूसरे पर स्लाइड करने की अनुमति देता है जैसे कलाई और टखना शामिल हैं। ये विभिन्न प्रकार के जोड़ शरीर को विभिन्न गतियाँ करने में सक्षम बनाते हैं।
In simple words: This diagram illustrates three types of joints: hinge joints (like the elbow), ball and socket joints (like the shoulder), and gliding joints (like the wrist), each allowing specific kinds of movement in the body.

🎯 Exam Tip: While drawing is not required in written exams, understanding the visual representation of different joint types is crucial for conceptual clarity and identification.

Question b. Structure of skin
Answer:
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव त्वचा की संरचना को दर्शाता है, जिसमें तीन मुख्य परतें हैं - सबसे बाहरी एपिडर्मिस, उसके नीचे डर्मिस, और सबसे निचली परत सबक्यूटिस (हाइपोडर्मिस)। एपिडर्मिस सुरक्षा प्रदान करती है, डर्मिस में रक्त वाहिकाएं और तंत्रिकाएं होती हैं, और सबक्यूटिस वसा का भंडारण करती है तथा शरीर के तापमान को बनाए रखने में मदद करती है। यह त्वचा की जटिल बहु-परत संरचना को स्पष्ट रूप से दर्शाता है।
In simple words: This diagram depicts the three main layers of the skin: the outermost epidermis, the middle dermis, and the innermost subcutis (hypodermis), showing how they are structured to perform various skin functions.

🎯 Exam Tip: Familiarity with the layered structure of the skin and the names of its main components is important for detailed descriptive questions.

Activity:

Question 1. Collect pictures of the different parts of the human skeletal system and paste them on chart paper. Write the functions of each, too.
Answer: Collect pictures of the different parts of the human skeletal system and paste them on chart paper. Write the functions of each, too.
In simple words: This activity involves identifying and visually representing various parts of the human skeleton, along with understanding their specific roles.

🎯 Exam Tip: Hands-on activities like this help in visual learning and retaining information about the human body's structure and function.

Question 2. Collect the pictures, newspaper cuttings, etc. which show the skeletal systems of various animals and observe the differences between them.
Answer: Collect the pictures, newspaper cuttings, etc. which show the skeletal systems of various animals and observe the differences between them.
In simple words: This activity focuses on comparative anatomy, encouraging students to observe and analyze structural differences in the skeletal systems of different animal species.

🎯 Exam Tip: Comparing different animal skeletons can enhance understanding of adaptation and evolution in biological structures.

Class 6 Science Chapter 8 Our Skeletal System And The Skin Important Questions And Answers

Choose The Correct Alternative:

Question 1. The ............... protects the brain.
(a) skull
(b) rib cage
(c) spine
(d) none of above
Answer: (a) skull
In simple words: The skull is a bony structure that encases and safeguards the delicate brain from injury.

🎯 Exam Tip: Knowing the primary protective function of the skull is a fundamental fact in human anatomy.

Question 2. X-rays were discovered by ................
(a) Sir C.V.Raman
(b) Galileo
(c) Sir Isaac Newton
(d) Roentgen
Answer: (d) Roentgen
In simple words: X-rays, a form of electromagnetic radiation used for imaging bones, were discovered by Wilhelm Conrad Roentgen.

🎯 Exam Tip: Attributing discoveries to the correct scientists is important for general science knowledge and historical context.

Question 3. The bones of ................ are immovable.
(a) hand
(b) leg
(c) spine
(d) skull
Answer: (d) skull
In simple words: Most bones in the skull are fused together, forming immovable joints that provide rigid protection for the brain, except for the lower jaw.

🎯 Exam Tip: Remember that while the skull offers significant protection, it is largely composed of immovable joints, a key characteristic differentiating it from other skeletal parts.

Question 4. We can move the bones of ................ in a 360° angle.
(a) elbow
(b) knee
(c) shoulder
(d) wrist
Answer: (c) shoulder
In simple words: The shoulder joint, a ball and socket joint, allows for a wide range of motion, including rotation in a 360-degree angle.

🎯 Exam Tip: Understanding which joints allow 360-degree rotation (ball and socket joints) helps in distinguishing between different joint types.

Question 5. Our body temperature usually remains constant at ................ °C.
(a) 32
(b) 35
(c) 37
(d) 40
Answer: (c) 37
In simple words: The normal internal body temperature for humans is maintained at approximately 37 degrees Celsius.

🎯 Exam Tip: Knowing the average human body temperature is a basic physiological fact that is often tested.

Question 6. The part of the skin which maintains body temperature is ................ .
(a) Epidermis
(b) Dermis
(c) Subcutaneous layer
(d) Network of blood vessels and nerve fibers
Answer: (c) Subcutaneous layer
In simple words: The subcutaneous layer, rich in fat, acts as an insulator, playing a significant role in maintaining the body's stable temperature.

🎯 Exam Tip: Differentiating the specific roles of each skin layer, especially in thermoregulation, is important for advanced understanding.

Fill In The Blanks:

Question 1. Except for the ................ none of the bones of the skull can move.
Answer: lower jaw
In simple words: All the bones of the skull are fixed and immovable, except for the lower jaw (mandible), which allows for talking and chewing.

🎯 Exam Tip: It's crucial to remember that the lower jaw is the only movable bone in the human skull.

Question 2. The spinal cord originates from the ................
Answer: brain
In simple words: The spinal cord extends from the base of the brain, forming a crucial part of the central nervous system.

🎯 Exam Tip: Understanding the connection between the brain and spinal cord is fundamental to neuroanatomy.

Question 3. The longest and the strongest bone in the human body is ................ .
Answer: femur
In simple words: The femur, or thigh bone, holds the distinction of being both the longest and strongest bone in the entire human skeleton.

🎯 Exam Tip: Identifying the femur as the longest and strongest bone is a common and important biological fact.

Question 4. ................ is the smallest bone in our body.
Answer: stirrup
In simple words: The stirrup, also known as the stapes, located in the middle ear, is the tiniest bone in the human body.

🎯 Exam Tip: Knowing the smallest bone (stirrup) as well as the largest (femur) demonstrates a good grasp of skeletal facts.

Question 5. The vertical, flat bone in the chest is called the ................ .
Answer: sternum
In simple words: The sternum, or breastbone, is the flat, vertical bone situated in the center of the chest, connecting the ribs.

🎯 Exam Tip: Correctly identifying the sternum is key to understanding the structure of the rib cage.

Question 6. The ................ joint moves in a 180° angle.
Answer: hinge
In simple words: Hinge joints, such as those found in the elbow and knee, allow movement predominantly in one plane, covering approximately a 180-degree angle.

🎯 Exam Tip: Understanding the range of motion (e.g., 180° angle) is a characteristic feature for identifying hinge joints.

Match The Columns:

Question 1. Match the following skeletal components with their bone counts:

🎯 Exam Tip: Memorizing the bone counts for key skeletal structures like the skull, rib cage, and spine is essential for factual recall questions.

Question 2. Match the following body parts with their joint types or characteristics:

🎯 Exam Tip: Accurately linking body parts to their functional descriptions or bone types demonstrates a good understanding of localized anatomy.

Right Or Wrong? If Wrong, Write The Correct Answers:

Question 1. The spine is a part of the appendicular skeleton.
Answer: Wrong: The spine is a part of the axial skeleton.
In simple words: The spine is part of the axial skeleton, which forms the central axis of the body, rather than the appendicular skeleton, which includes the limbs.

🎯 Exam Tip: Clearly distinguishing between the axial and appendicular skeleton is a foundational concept in skeletal anatomy.

Question 2. Ankle joints are gliding joints.
Answer: Right
In simple words: The ankle contains gliding joints that allow bones to slide over each other, providing flexibility and movement.

🎯 Exam Tip: Knowing specific examples of gliding joints, like the ankle, is important for identifying joint types.

Question 3. All the skull joints are immovable.
Answer: Wrong: Except lower jaw, all the skull joints are immovable.
In simple words: While most skull joints are indeed immovable, the joint connecting the lower jaw (mandible) to the skull is movable, allowing for crucial functions like chewing and speaking.

🎯 Exam Tip: It is important to remember the exception of the lower jaw when discussing the movability of skull joints.

Question 4. The skin maintains normal body temperature.
Answer: Right
In simple words: The skin plays a crucial role in thermoregulation, helping to maintain a stable internal body temperature through mechanisms like sweating and regulating blood flow.

🎯 Exam Tip: Recognizing the skin's function in maintaining body temperature is a key aspect of its role as an organ system.

Answer In One Word:

Question 1. The part which protects the heart and lungs.
Answer: Rib cage
In simple words: The rib cage is the bony structure that surrounds and protects the vital organs of the chest, including the heart and lungs.

🎯 Exam Tip: Identifying the rib cage as the protector of the heart and lungs is a basic anatomical fact.

Question 2. Ali falls down and his elbow is broken.
Answer: Fracture
In simple words: A fracture is the medical term for a break or crack in a bone, commonly occurring due to falls or impacts.

🎯 Exam Tip: Using the correct medical terminology, such as "fracture" for a broken bone, is important.

Question 3. The image which spots the broken bone.
Answer: X-ray
In simple words: An X-ray is a diagnostic imaging technique that uses radiation to produce images of bones, effectively revealing fractures or breaks.

🎯 Exam Tip: Understanding the application of X-rays in diagnosing bone injuries is relevant to both science and health education.

Question 4. The biotic component of our body.
Answer: Bone cell
In simple words: Bone cells are the living, biological components within bone tissue, responsible for its formation, maintenance, and repair.

🎯 Exam Tip: Differentiating between biotic (living) and abiotic (non-living) components within body structures is a key biological concept.

Question 5. The part which protects the vertebral column.
Answer: Spine
In simple words: The spine, or vertebral column, provides protection to the delicate spinal cord while also supporting the body's structure.

🎯 Exam Tip: Recognizing the spine's dual role in support and protection of the spinal cord is crucial.

Question 6. The part which connects the bone in our body.
Answer: Ligament
In simple words: Ligaments are strong, fibrous tissues that connect bones to other bones, providing stability to joints.

🎯 Exam Tip: Differentiating between ligaments (bone to bone) and tendons (muscle to bone) is a common point of confusion; ensure clarity.

Question 7. The organ which helps us to sense whether something is hot or cold.
Answer: Skin
In simple words: The skin, equipped with various sensory receptors, acts as the primary organ for detecting sensations like temperature (hot or cold).

🎯 Exam Tip: Understanding the skin's role as a sensory organ is fundamental to its overall function.

Question 8. The pigment which gives colour to the skin.
Answer: Melanin
In simple words: Melanin is the natural pigment produced by specialized skin cells, responsible for giving color to skin, hair, and eyes.

🎯 Exam Tip: Linking melanin directly to skin pigmentation is a core concept in biology and human physiology.

Can You Tell?

Question 1. What is a fracture? How will you help a friend who has met with an accident and fractured his leg?
Answer: Fracture is a crack or break in a bone. Fracture may occur due to accident or fall from height or injury. If my friend's leg is fractured, then. I would -
1. Ask him to prevent any movement of the fractured part.
2. Get immediate medical help.
3. Take the x-ray image of the fractured or swollen part.
4. An x-ray image shows the exact spot where the bone is broken. This will help in providing proper treatment.
In simple words: A fracture is a broken bone, often caused by accidents; in such a situation, it is critical to immobilize the injured leg, seek immediate medical attention, and obtain an X-ray for accurate diagnosis and treatment.

🎯 Exam Tip: Providing a clear definition of fracture along with practical first aid steps demonstrates both theoretical knowledge and real-world application.

Question 2. What are the properties of bones?
Answer:The properties of bones are:
1. Bones are hard and not flexible.
2. Bone cells are composed of two main constituents:
• Bone cells are biotic components.
• Calcium carbonate, calcium phosphate, minerals and salts are abiotic components.
3. Calcium imparts strength to bones.
4. As we grow the size and length of bones increases upto a certain limit.
In simple words: Bones are rigid structures made of both living cells and non-living minerals like calcium, which provides their hardness and strength, and they grow in size during development.

🎯 Exam Tip: Focus on the composition and physical characteristics of bones, particularly their hardness and mineral content, as key properties.

Question 3. What is human skeletal system? How is it divided?
Answer:
1. All the bones together form a framework or a skeleton.
2. All the bones of the body along with cartilage together form the skeletal system.
3. The human skeletal system can be divided into two parts - the axial skeleton and the appendicular skeleton.
4. The axial skeleton consists of the skull, the spine and the rib cage. These are situated symmetrically along the central axis.
5. The appendicular skeleton consists of the bones of arms and legs on either side of the central axis.
In simple words: The human skeletal system is the framework of bones and cartilage that supports the body, and it's divided into the axial skeleton (skull, spine, rib cage) and the appendicular skeleton (limbs).

🎯 Exam Tip: Remember the two main divisions of the skeletal system - axial and appendicular - and be able to list the main bones included in each category for full marks.

Question 4. What is a joint? What are it's types?
Answer:Joints are places where two or more than two bones are connected to each other.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव शरीर में विभिन्न प्रकार के जोड़ों को दर्शाता है। इसमें चलायमान और अचल दोनों तरह के जोड़ शामिल हैं, जिनमें कोहनी और घुटने में कब्ज़े का जोड़, कंधे और कूल्हे में गेंद और सॉकेट जोड़, और कलाई और टखने में ग्लाइडिंग जोड़ के उदाहरण हैं, साथ ही खोपड़ी के अचल जोड़ भी दिखाए गए हैं।
In simple words: A joint is where bones meet, allowing movement (like hinge, ball and socket, gliding joints) or providing stability (like immovable skull joints).

🎯 Exam Tip: Clearly define what a joint is and give examples for each major type of movable joint (hinge, ball and socket, gliding) as well as immovable joints.

Question 5. Describe the structure of skin.
Answer:
1. Human skin is made up of two main layers- outermost layer, epidermis and layer below it called dermis.
2. Below dermis there is a network of blood vessels and nerve fibers.
3. Under this layer there is a subcutaneous layer, which maintains body temperature.
4. The epidermis has various layers.
5. There are sweat glands in the skin which secrete sweat.
In simple words: The skin has two main layers, the outer epidermis and the inner dermis, with a subcutaneous layer beneath that helps regulate body temperature and contains sweat glands.

🎯 Exam Tip: When describing the skin's structure, ensure you name the main layers (epidermis, dermis, subcutaneous) and mention key features like blood vessels, nerve fibers, and sweat glands.

Question 6. Write a short note on melanin.
Answer:
1. Melanin is a pigment present in the cells of epidermis.
2. Melanin is synthesized in certain glands in the skin.
3. The percentage of melanin decides the fairness or darkness of the skin.
4. Melanin protects our skin and the inner parts from ultraviolet sunrays.
In simple words: Melanin is a pigment found in the skin's epidermis, produced by glands, that determines skin color and provides protection against harmful UV rays from the sun.

🎯 Exam Tip: Remember melanin's role in skin color, its location (epidermis), and its crucial function of protecting against UV radiation for a complete answer.

Use Your Brain Power!

Question 1. Which colour of the skin will give greater protection from sun's rays?
Answer:Darker colour will give greater protection.
In simple words: Darker skin, which contains more melanin, offers better natural protection against the sun's harmful rays.

🎯 Exam Tip: Connect skin color directly to melanin content and its protective function against UV radiation for a precise answer.

Give Scientific Reasons:

Question 1. We are able to bend down at our will.
Answer:
1. 33 bones of the spine are placed straight one above the other.
2. They are arranged flexibly.
3. Their flexibility allows us to bend down at our will.
In simple words: Our spine is made of 33 flexibly arranged bones called vertebrae, which allows us the flexibility to bend and move our torso as we wish.

🎯 Exam Tip: The key to bending is the flexible arrangement of multiple small bones (vertebrae) in the spine, not a single rigid bone.

Question 2. Calcium is an important mineral.
Answer:
1. Calcium imparts strength to our bones.
2. If we are calcium deficient, possibility of bone fracture during a fall or an accident increases.
3. Hence, calcium is an important mineral.
In simple words: Calcium is vital because it makes our bones strong, and a lack of it can lead to weaker bones more prone to fractures.

🎯 Exam Tip: Highlight calcium's role in bone strength and the increased risk of fractures due to calcium deficiency.

Question 3. Sweating helps to lower the body temperature.
Answer:
1. In the hot sun, the temperature of the skin rises.
2. The sweat is released.
3. The heat required for the evaporation of sweat is drawn from the body itself.
4. Hence, sweating lowers the body temperature.
In simple words: When we sweat, the evaporation of that sweat from our skin takes heat away from our body, thus cooling us down and lowering our body temperature.

🎯 Exam Tip: Explain the process: sweat release, evaporation, and the absorption of body heat during evaporation as the mechanism for cooling.

Question 4. Some people have jet black hair, while others have brown or reddish hair.
Answer:
1. It is melanin that determines the colour of our hair.
2. Jet black hair is due to pure melanin.
3. Brown hair is due to sulphur in the melanin.
4. Reddish hair is due to iron in the melanin.
In simple words: Hair color is determined by melanin; pure melanin results in jet black hair, while the presence of sulfur or iron in melanin leads to brown or reddish hair, respectively.

🎯 Exam Tip: Attribute different hair colors to variations in melanin composition, specifically linking pure melanin to black, sulfur to brown, and iron to reddish hair.

Question 5. Observe and discuss: Your grandmother has wrinkles on her skin.
Answer:
1. As we grow older, the proportion of fat beneath the skin reduces.
2. However, previously tout skin does not shrink.
3. This causes wrinkles on the face of older people.
In simple words: As people age, the fat layer under the skin decreases, but the skin itself doesn't shrink proportionally, leading to loose skin and the formation of wrinkles.

🎯 Exam Tip: Focus on the loss of subcutaneous fat and the skin's inability to shrink with age as the primary reasons for wrinkles.

What Will Happen If:

Question 1. If skin had no sweat glands.
Answer:Skin regulates body temperature by releasing sweat. If skin had no sweat glands then we will not be able to maintain our body temperature at a constant 37°C.
In simple words: Without sweat glands, our skin wouldn't be able to release sweat to cool down, making it impossible to maintain a stable body temperature in hot conditions.

🎯 Exam Tip: Emphasize the critical role of sweat glands in thermoregulation; their absence would lead to an inability to maintain constant body temperature.

Can You Recall?

Question 1. Which organ help us to sense whether something is hot or cold, rough or smooth, etc?
Answer:The skin functions as the sensory organ of touch.
In simple words: The skin is our primary sensory organ for touch, allowing us to feel temperature, texture, and pressure.

🎯 Exam Tip: Clearly state that the skin is the sensory organ for touch and its various sensations like temperature and texture.

Question 2. What happens when we walk or play in the hot sun?
Answer:When we walk or play in the sun, we get tired, our skin secrete sweat.
In simple words: When active in the hot sun, our body heats up, leading to fatigue and the release of sweat from our skin to cool down.

🎯 Exam Tip: Mention both the feeling of tiredness and the physiological response of sweating as direct effects of physical activity in the hot sun.

Observe The Figure And Label As Directed.

Question 1. In the above figure label the parts marked a, b, c, d, e and hence show axial and appendicular skeleton.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव कंकाल प्रणाली का एक पूर्ण दृश्य दर्शाता है। इसमें खोपड़ी, पसलियों का पिंजरा, रीढ़, हाथ और पैर जैसे शरीर के विभिन्न भागों को 'a', 'b', 'c', 'd', 'e' अक्षरों से चिह्नित किया गया है, जो अक्षीय और उपांगीय कंकाल के घटकों को समझने में मदद करता है।
Answer:
(a) Skull
(b) Rib cage
(c) Spine
(d) Arm
(e) Leg
Axial skeleton: skull, the spine and rib cage
Appendicular: legs, arms
In simple words: The diagram displays the human skeleton, identifying the skull, rib cage, spine, arms, and legs, and distinguishing between the central axial skeleton and the limb-based appendicular skeleton.

🎯 Exam Tip: For diagrams of the skeletal system, correctly identify the major bones and clearly differentiate between axial skeleton components (skull, spine, rib cage) and appendicular skeleton components (limbs).

Question 2. In the given figure, name the type of bones marked a, b, c, d. State where they are seen in our body.
ℹ️ चित्र व्याख्या (Diagram Explanation): यह चित्र मानव शरीर में पाए जाने वाले विभिन्न प्रकार की हड्डियों को दर्शाता है, जिन्हें 'a', 'b', 'c', 'd' अक्षरों से चिह्नित किया गया है। इसमें पसलियों के पिंजरे और ग्लाइडिंग जोड़ में सपाट हड्डियों (a), उंगली में छोटी हड्डियों (b), कशेरुक स्तंभ में अनियमित हड्डियों (c), और पैरों व बांहों में लंबी हड्डियों (d) के उदाहरण शामिल हैं।
Answer:
(a) Flat bones - rib cage and gliding joint
(b) small bones - finger
(c) Irregular bones - vertebal column
(d) Long bones - legs, arms
In simple words: The figures illustrate different bone types: flat bones in the rib cage, small bones in the finger, irregular bones in the vertebral column, and long bones in the legs and arms.

🎯 Exam Tip: When identifying bone types from diagrams, ensure you correctly classify them (flat, small, irregular, long) and provide accurate examples of where they are found in the body.