CBSE Class 10 Biology Life Processes Worksheet Set D

Question. Name the green pigment present in the leaves of a plant.
Answer: Chlorophyll

Question. Which enzyme present in saliva breaks down starch?
Answer: The saliva contains an enzyme called salivary amylase that breaks down starch.

Question. Give one point which is common for both aerobic and anaerobic respiration.
Answer: In both aerobic and anaerobic respiration, the chemical used is glucose.

Question. Why does our mouth ‘water’ when we see or eat a food which we really like?
Answer: Due to the production of saliva by the salivary glands in the mouth.

Question. Name the structure which regulates the exit of waste material.
Answer: Anal sphincter.

Question. What is common for cuscuta, ticks and leeches?
Answer: Cuscuta, ticks and leeches, all has parasitic mode of nutrition, they harm their host while taking nutrition.

Question. What is the function of digestive enzymes?
Answer: Enzymes break-down the various complex components of food into simple and soluble components so that they can be absorbed easily.

Question. Due to availability of less water, how does the plant cope up with lack of water in desert conditions?
Answer: They open their stomata at night and stomata remain closed during day time, to conserve moisture.

Question. Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
Answer: As in multicellular organisms, all the cells are not in direct contact with environment, simple diffusion does not meet the requirement of all the body cells.

Question. Why the walls of trachea are supported by cartilaginous rings?
Answer: The trachea is supported by cartilaginous rings which prevent the collapsing even when there is not much air in it.

Question. What will be the outcome if a farmer floods his field everyday?
Answer: Respiration of plants will be affected because the oxygen present in the interspaces of the soil will be replaced by water.

Question. If a person is working on a treadmill in a gymnasium, will it effect his rate of breathing? How?
Answer: Yes, it will affect his rate of breathing. The rate of breathing will become fast to supply more oxygen to meet the increased demand of energy.

Question. After a vigorous exercise, you may experience cramps in your leg muscles. Why does this happen?
Answer: The sudden build up of lactic acid in our muscles during vigorous, exercise, causes muscular cramps in our leg muscles.

Question. What will happen if carbon monoxide combines with hemoglobin?
Answer: If the hemoglobin binds with carbon monoxide strongly, the oxygen will not be carried with blood leading to death of the organism.

Question. Chloroplast are called energy convertors. Explain.
Answer: Chloroplasts are called energy convertors because they trap the solar energy and convert it into chemical energy.

Question. How are the lungs designed in human beings to maximize the area for exchange of gases?
Answer: In lungs, the bronchioles terminate in balloon-like structures called alveoli. The alveoli contain network of blood capillaries that increase the surface area for exchange of gases.

Question. What is the role of saliva in the digestion of food?
Answer: The saliva contains an enzyme called salivary amylase that breaks down starch which is complex molecule into glucose 

Question. While eating you are advised not to talk Why are you advised so?
Answer: We are advised so because while eating some food particles might enter the wind pipe which can lead to choking.

Short  Answer type Question

Question. Name the substrates for the following enzymes
a) trypsin
b) amylase
c) pepsin
d) lipase
Answer: a) Protein
b) Starch
c) Protein
d) Lipids

Question. What criteria do we use to decide whether something is alive?
Answer: All the living organism must have movement at molecular levels along with respiration and other life process like nutrition, respiration, transportation and excretion to be called alive.

Question. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Answer: Adaptation of terrestrial organism over aquatic organism for efficient uptake of oxygen from air –
(i) Increased respiratory surface area.
(ii) Very fine and delicate surface for easy exchange of oxygen and carbon – dioxide.
(iii) Placement of respiratory surface within the body for protection
(iv) Mechanism for moving the air in and out of respiratory surface where the oxygen is absorbed.

Question. We say that movement is a characteristic of living organisms but we always don’t see visible movements in plants. Comment.
Answer: We always don’t see visible movements in plants. It does not mean that they are not alive.
Molecular movements take place in their body.

Question. What are the two stages in photosynthesis?
Answer: Two stages in photosynthesis –
a) Light reaction – Light energy breaks up water molecular into hydrogen and oxygen, called photolysis of water
b) Dark reaction – Fixation and conversion of carbon – dioxide (CO2) into a simple carbohydrates glucose.

Question. Mucus is not used for churning the food or digesting it. Then why is it secreted in the stomach?
Answer: Mucus is secreted in the stomach to protect its inner lining form being damaged by HCI.
Excessive secretion of HCI can damage the lining and lead to peptic ulcer.

Question. What is the advantage of four chambered of heart?
Answer: The right and left parts are separated by a septum to prevent oxygenated and deoxygenated blood from mixing. This fulfills the constant use of energy to maintain their body temperature. Their energy needs are high, which are fulfilled efficiently because of non – mixing of oxygenated & deoxygenated blood.

Question. In the process of Photosynthesis food A is prepared which gets converted into food
B. What are A and B? Why is A converted to B?
Answer: Food A is glucose and food B is Starch.
A is converted to B as B is insoluble form of carbohydrate. It is more compact and hence, suitable for storage.

Question. What type of respiration takes place in human muscles during vigorous exercise and why?
Answer: During vigorous exercise, anaerobic respiration takes place in human muscles. During exercise our energy requirement increase, so our striated muscles start respiring anaerobically in the lack of oxygen and producers ATP molecules.

Question. Meat is easier to digest as compared to grass. Why?
Answer: It is easier to digest meat because our digestive juices contain enzymes which can easily digest meat but our body does not digest cellulose which is a main component of grass.

Question. What is villi? What are its functions?
Answer: Finger like projection present in the inner lining of small intestine are called villi. They increase the surface area for the absorption of digested food in the small intestine.

Question. What is the role of glomerulus in kidney?
Answer: Glomerulus is a group of capillaries present in the cup like Bowman’s Capsule. It receives blood from renal artery which brings excretory wastes from body to the kidney. It filters water, salts, glucose, urea, the nitrogen containing end products of proteins and yellow bile compounds from the liver.

Question. When we are asleep we are not performing any activity still our life processes are going on. Why?
Answer: “The maintenance functions of living organisms must go on even when they are not doing anything particular.” That is why the life processes are going on even while we are asleep or not performing any activity.

Question. Why is it essential to match the blood groups of donors and receiver person before arranging transfusion of blood?
Answer: RBC’s of blood carries antigen as well as antibody. If blood is not matched before transfusion then blood of receiver start producing antibodies against donor blood and destroys blood cells, this causes deficiency of blood and causes death.

Question. Name the respiratory organs of (i) fish (ii) mosquito (iii) earthworm.
Answer: Fish - gills
Mosquito - Trachea (air tubes)
Earthworm - moist skin

Question. What are the raw materials for photosynthesis?
Answer: Raw materials for photosynthesis are –
a) Carbon – dioxide
b) Water
c) Chlorophyll and Sunlight

Question. How is opening and closing of stomata regulated?
Answer: The closing and openings of the stomata is regulated by guard cells. When the guard cells swell or turgid due to entry of water, the stomata are opened. The guard cells shrink due to loss of water the stomata get closed.

Question. State two vital functions of kidney.
Answer: Function of kidney are –
1) It maintains water balance in the body tissues.
2) It controls calcium levels in the blood to maintain healthy bones.

Question. What is the role of diaphragm during inhalation and exhalation?
Answer: Diaphragm changes its shape during inhalation and exhalation and increases and decreases volume of thoracic cavity respectively. This causes entry and expel of air from lungs.

Question. If you compare your rate of breathing by feeling your chest movement with the number of times a fish opens and closes its mouth. Which will be higher and way?
Answer: The number of times a fish opens and closes its mouth will be higher as the amount of dissolved oxygen in water is fairly low compared to the amount of oxygen in the air.
Therefore, rate of breathing in aquatic organisms is much faster than in terrestrial organisms.

Question. Why is it necessary to separate oxygenated & deoxygenated blood in mammals & birds?
Answer: Separation of oxygenated and deoxygenated blood allows good supply of oxygen to the body. This system is useful in animals that have high energy requirement Mammals and birds constantly need oxygen to get energy to maintain constant body temperature

Question. Why is the rate if breathing much faster in aquatic organisms than those of terrestrial organisms?
Answer: The aquatic organisms obtain oxygen dissolved in water. As compared to air, the availability of oxygen in water is fairly low. Hence, the aquatic organisms have to breathe faster as compared to the terrestrial organisms.