CBSE Class 10 Biology Life Processes Worksheet Set F

Question: Which is the universal source of energy in all cells?
Answer: ATP, Adenosine Tri Phosphate.

Question: What would be the consequences of deficiency of haemoglobin in our bodies?
Answer: Anaemia.

Question: If no apparent work is being done by an organism, why does it takes food? 
Answer: To carry out life processes, growth, reproduction and for repair of worn out tissues.

Question: Name the type of blood vessels, which carry blood from organs to the heart.
Answer: Veins.

Question: What is peristalsis? 
Answer: Contraction and expansion of alimentary canal to push the food forward is called peristalsis.

Question: How does nutrition in a fungus different from that in a tapeworm? 
Answer: Fungus derives its nutrition either by parasitic or saprophytic manner while tapeworm is only parasitic.

Question: What is the stored form of carbohydrates in plants and animals respectively?
Answer: Starch and glycogen.

Question: What is the role of cartilaginous rings on trachea?
Answer: They prevent the collapsing of trachea when there is no air present in it.

Question: Name mode of nutrition in the following organisms:
(a) Fungi (b) Amoeba
Answer: a. Fungi – saprophytic
b. Amoeba — animal like nutrition

Question: How is the passage of food regulated from stomach onwards?
Answer: Food is passed down to small intestine through sphincter muscles present in last part of stomach.

Question: Which pathway is common to both aerobic and anaerobic respiration?
Answer: Glycolysis.

TWO MARKS QUESTIONS

Question: List two factors which decide direction of diffusion of oxygen and carbon dioxide.
Answer: Environmental conditions and requirement of the plants decide direction of diffusion of oxygen and carbon dioxide.

Question: What are the strategies of plants to get rid of their wastes?
Answer: a. They throw away oxygen and water vapour through stomata.
b. Some wastes like gums, oil and resins may be stored in old xylem or wood in stem.
c. Some wastes may be stored in leaves and bark and shed off from time to time.
d. Roots can also throw some wastes.

Question: Why do we feel pain or cramps in muscles after a vigorous exercise?
Answer: Actively metabolizing cells of an extremely active skeletal muscle, during heavy exercise, carry oxidation in the anaerobic condition inside the muscle cell, we feel pain after a vigorous exercise because of production of ATP by anaerobic respiration in leg muscles.

Question: How do plants exchange gases?
Answer: Plants exchange gases through stomata. Large intercellular spaces ensure that each cell is in contact with air. Carbon dioxide and oxygen are exchanged here.

Question: List two ways in which plants can get rid of the wastes.
Answer: They can throw gases and excess water through stomata through diffusion. They can store wastes like gums and resins in old xylem tissue (wood).

Question: How are fats digested in our bodies? Where does this process take place?
Answer: Fats are first emulsified with the help of bile salts followed by their breakdown in fatty acids and glycerol due to the action of lipase. All these events take place in first part of small intestine-duodenum.Saprophytic

Question: What is the role of acid and mucus in stomach?
Answer: It kills germs in food and provides acidic medium for the action of pepsin enzyme to digest the proteins in stomach.
Mucus protects the wall of stomach from the action of acid and pepsin.

Question: Which digestive secretion does not contain any enzyme but is important? Discuss.
Answer: Bile juice from liver. It contains bile salts which are necessary for emulsification of fats. It means breaking down large fat drops to very fine droplets so that lipase can act upon them easily.

Question: Discuss how the roles of vena cava and pulmonary veins different from each other?
Answer: Pulmonary vein carries oxygenated blood from lungs to left auricle of heart in humans.
Vena Cava collects deoxygenated blood from all parts of the body and transport it to right auricle of the heart in human.

Question: Differentiate between Artery and Veins.
Answer: Arteries carry blood away from the heart (arteriole: small arterial branch). They have thick and flexible walls to endure higher pressure of blood.
Veins transport blood toward the heart (venue:small vessel that carries blood from capillaries to veins). They have thinner wall but there are valves in them at regular distance to prevent back flow of blood especially when blood is returning back to heart from lower organs.

Question: How does nutrition take place in Amoeba? How is it different in Paramoecium? 
Answer: Nutrition in amoeba: It occurs through phagocytosis. It capture food by pseudopodia (ingestion) ingested food, enclosed in cell membrane is called food vacuole. The food is broken with enzymes present in cytoplasm and undigested food ‘is thrown out through cell membrane.
Nutrition in Paramoecium: The cell has a definite shape and food is taken in at a specific spot. Food is moved to this spot by the movement of cilia present on the entire surface of the cell.

Question: How is the small intestine designed to absorb digested food?
Answer: Walls of small intestine has finger like projection called villi to increase surface area. The food is absorbed by villi and brought into blood. Fat is brought into lymph vessel.

Question: What is the role of valves in veins?
Answer: They prevent the back flow of blood especially when it moves against gravity and under low blood pressure.

Question: Write a balanced equation for photosynthesis.
Answer: 6CO₂+ 12H₂O ^Light →  C6 H₁₂ O₆+ 6H₂0+ 6O₂
                             ^Chlorophyll 

Question: Why are arteries thick walled and elastic?
Answer: Arteries receive the blood pumped by heart with lots of pressure hence to tolerate and sustain this pressure they are thick walled and elastic.

THREE MARKS QUESTIONS

Question: a. What is the role of mucus in stomach?
b. What are the two vital functions of human kidney?
Answer: a. To protect the stomach lining from the action of acid and pepsin.
b. The two vital functions of human kidney are:
(i) Excretion – Removal of toxic wastes like urea, uric acid.
(ii) Osmoregulation – The process of maintaining the right amount of water and proper ionic balance in body. It is done by controlling the amount of water and salts reabsorbed by  nephron – tubules.

Question: a. How is oxygen and carbon dioxide exchanged between blood and tissue? How are the gases transported in human being?
b. What is haemoglobin? 
Answer: a. Exchange of gases in tissues occurs through diffusion. Oxygen is carried as oxyhaemoglobin from lungs to tissues. It dissociates and carbon dioxide diffuses out into blood from tissues. It is transported in dissolved form and reaches lungs where again it diffuses to alveoli.
b. Respiratory pigment: Haemoglobin is a red coloured protein present in red blood cells. Haemoglobin has affinity for O₂.

Question: What are the important features of all respiratory structures in animals?
                                          or
How are alveoli designed to maximize the exchange of gases?
Answer: All respiratory system have some important features.
a. Large surface area.
b. Thin and delicate surface for diffusion and exchange of gases. It is generally located in protected inner part of body.
c. Rich blood supply to respiratory organ. Since all of them are present in alveoli hence it is perfectly designed for exchange of gases.

Question: What is sequence of steps in photosynthesis? How is it different in desert plants and those in temperate regions?
Answer: Chloroplast (chlorophyll), on exposure to light energy, becomes activated by absorbing light energy, and splits water (photolysis of water) to oxygen and hydrogen.
Hydrogen reduces CO₂, and synthesizes glucose. In plants of temperate regions, stomata open during day to take in CO₂ and release O₂.
Desert plants open stomata at night to check excessive loss of water hence sequence of steps of photos ynthesis are slightly different.
These plants take up carbon dioxide at night and prepare an intermediate which is acted upon by the energy absorbed by the chlorophyll during the day.

Question: What is excretion? Name some parts in our body involved in this life process?
Answer: Excretion means throwing out metabolic waste from living body. Many organs perform this process such as a. Kidneys remove nitrogenous wastes like urea and
uric acid in urine.
b. Sweat and oil by glands in skin.
c. Carbon dioxide and water vapor by lungs.
d. Faces or undigested food by large intestine.
e. Bile pigments by liverIt also converts toxic ammonia to urea.It also converts toxic ammonia to urea.

Question: What is the need to have a transport system in complex organisms?
Answer: The transport system of an animal moves substances to where they are needed in the body. Even the smallest animal must have the means of transporting substances around its body. Oxygen and food molecules must move to all the cells, and the waste products must be removed from the cells and expelled into the environment. It occurs through diffusion mainly.
In a multicellular organism, all cells are not in contact with the surrounding hence diffusion will be insufficient for it. A variety of fluid systems, called vascular systems, help such transport in most members of the animal kingdom.

Question: What is the composition of urine? Are glucose and proteins normally present in urine? Why? How is volume of urine regulated?
Answer: The urine contains mainly water, various salts, urea and uric acid. No, they are not present in urine as glucose is reabsorbed by nephron while protein are not filtered from blood in glomerulus in a healthy kidney.
Volume of urine is regulated by
a. The amount of excess water.
b. The amount of dissolved waste in blood.

FIVE MARKS QUESTIONS

Question: In order to prepare a temporary mount of a leaf peel to observe stomata, which chemicals used for staining and mounting?
Answer: The chemicals used for staining and mounting respectively are safranin and glycerine.

Question: Usman collected her saliva and mixed it with liquid A in the test tube. In another test tube she took only liquid A after about 10 minutes, she added a few drops of iodine solution to the mixture in the first test tube. It did not show any colour but when she treated the other test tube with iodine, a blue black colour appeared. Now answer the following questions:
a. What is the aim of this activity?
b. What is liquid A?
c. Why did the first test tube not show any colour change with iodine while the second one did?
d. Which enzyme is responsible for such a result?
e. Why does a piece of bread chewed for a long time tastes sweet?
Answer: a. To show the action of salivary amylase on starch.
b. Liquid A is starch.
c. The first test tube did not show any colour change with iodine because starch was not present anymore in it. It was already digested by salivary amylase present in saliva. The colour of liquid in the second one changed to blue black as the starch was still unchanged due to absence of the enzyme.
d. Salivary amylase enzyme is responsible for such a result.
e. A piece of bread chewed for a long time tastes sweet because the starch is broken down by salivary amylase to maltose sugar.

Question: What are the different components of blood? Give the function of each of them. 
Answer: Blood is a liquid connective tissue. It is chiefly formed of two components:
a. Fluid matrix or plasma: It is of pale colour and transports much substance like dissolved carbon dioxide, glucose, amino acids, urea etc.
has mainly water, some proteins like albumin, fibrinogen (blood clotting protein) and many other substances to be transported.
b. Cellular elements which are of three types:
(1) Red blood corpuscles (R.B.C) or erythrocyt.es, which transport O₂ and CO₂. They are enucleated, disc shaped, full of a red colored protein pigment, hemoglobin.
(2) White blood corpuscles (W.B.C) or leucocytes,which fight disease-causing agent. They are larger, nucleated and are of different types.
(3) Blood platelets or thrombocytes, which help in blood clotting. They are fragments of some larger cell hence do not have nucleus.

Question: (i) Explain the importance of the following:
(a) salivary amylase
(b) villi
(c) pepsin
(ii) Explain how oxygenated blood from this chamber is sent to all parts of the body.
Answer: (i) (a) Salivary amylase: It’s an enzyme present in the saliva, secreted by salivary glands. It digests starch into maltose there by starting the digestion of carbohydrate in the buccal cavity.
(b) Villi: They increase the surface area for absorption of digested food into the blood.
(c) Pepsin: It is a digestive enzyme secreted by gastric glands. It is responsible for the digestion of proteins in stomach.
(ii) When the left atrium contracts, the oxygenated blood is poured into the left ventricle. When the left ventricle contracts the blood is pumped into the aorta, the largest artery which distributes it to all the parts of the body through arteries.

Question: How are oxygen and CO₂ transported in human beings? How are lungs designed to maximise the area Download more materials in free at : for exchange of gases?
Answer: Exchange of gases in tissues occurs through diffusion.
Oxygen is carried as oxyhaemoglobin from lungs to tissues. It dissociates and carbon dioxide diffuses out into blood from tissues. It is transported in dissolved form and reaches lungs where again it diffuses to alveoli. Lungs have a tree like branching pattern of bronchi and bronchioles. The terminal part of bronchiole ends into sac like structures called alveoli which are present in groups. Alveoli have curved wall to increase surface area for exchange of gases. The wall of alveoli is extremely thin and is lined by blood capillaries.