CBSE Class 10 Science Biology Life Process Respiration Assignment

MULTIPLE CHOICE QUESTIONS

Question. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm.
(b) mitochondria.
(c) chloroplast.
(d) nucleus.
Answer : B

Question. During cellular respiration one molecule of glucose is first broken down into two molecules of
(a) Acetic acid
(b) Pyruvic acid
(c) Lactic acid
(d) None of the above
Answer : B

Question. Which of the following statements about the autotrophs is incorrect?
(a) They synthesise carbohydrates from carbon dioxide and water in the presence of sunlight and chlorophyll
(b) They store carbohydrates in the form of starch
(c) They convert carbon dioxide and water into carbohydrates in the absence of sunlight
(d) They constitute the first trophic level in food chains
Answer : C

Question. Choose the function of the pancreatic juice from the following
(a) trypsin digests proteins and lipase carbohydrates
(b) trypsin digests emulsified fats and lipase proteins
(c) trypsin and lipase digest fats
(d) trypsin digests proteins and lipase emulsified fats
Answer : D

Question. Choose the correct path of urine in our body
(a) kidney →ureter →urethra →urinary bladder
(b) kidney →urinary bladder →urethra →ureter
(c) kidney →ureters →urinary bladder →urethra
(d) urinary bladder →kidney →ureter →urethra
Answer : B

Question.The parts shown as A and B in the given diagram are

The parts shown as A and B in the given diagram are
(a) A is epidermal cell, B is stomatal pore
(b) A is guard cell, B is stomatal pore
(c) A is epidermal cell, B is guard cell
(d) A is guard cells, B is epidermal cell
Answer : B

Question. In normal expiration, the diaphragm is
(a) Arched
(b) Flattened
(c) Perforated
(d) None of these
Answer : A

Question. Villi present on the inner lining of the intestinal wall
(a) Secretes enzymes for digestion
(b) Secretes hormones
(c) Decreases the surface area for absorption
(d) Increases the surface area for absorption
Answer : D

Question. The correct pathway of blood in circulatory system is
(a) atria → ventricles → arteries → veins
(b) ventricles → atria → veins → arteries
(c) ventricles → veins → arteries → atria
(d) veins → ventricles → atria → arteries
Answer : A

Question. Respiration is a process in which
(a) Energy is stored in the form of ADP
(b) Energy is released and stored in the form of ATP
(c) Energy is used up
(d) Energy is not released at all.
Answer : B

Question. Full form of ATP?
(a) Adenosine Triphosphate
(b) Adenosine Tetraphosphate
(c) Adenine Triphosphate
(d) Adinosine Tripolymer
Answer : A

Question. The xylem in plants are responsible for
(a) transport of water.
(b) transport of food.
(c) transport of amino acids.
(d) transport of oxygen
Answer : A

Question. Why blood is red?
(a) due to presence of oxygen
(b) due to presence of haemoglobin
(c) due to presence of CO₂
(d) due to presence of WBC
Answer : B

Question. If kidney fails to reabsorb water, the tissues would
(a) remain unaffected
(b) shrink to shrivel
(c) absorb water from blood
(d) take more oxygen from blood
Answer : B

Question. The autropic mode of nutrition requires
(a) carbon dioxide and water.
(b) chlorophyll.
(c) sunlight.
(d) all of the above
Answer : D

Question. The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(a) cytoplasm.
(b) mitochondria.
(c) chloroplast.
(d) nucleus.
Answer : B

Question. Chyme is ____.
(a) Digestive enzyme secreted by stomach.
(b) Hormone secreted by islets of Pancreas
(c) food which enters into intestine from stomach.
(d) Part of bile juice which stores in gall bladder
Answer : B

Question. Haemoglobin is a type of
(a) Carbohydrate
(b) Skin Pigment
(c) Vitamin
(d) Respiratory Pigment
Answer : D

Question. Which is the correct sequence of parts in human alimentary canal?
(a) Mouth →stomach →small intestine →oesophagus →large intestine
(b) Mouth →oesophagus →stomach →large intestine →small intestine
(c) Mouth →stomach →oesophagus →small intestine →large intestine
(d) Mouth →oesophagus →stomach →small intestine →large intestine
Answer : D

Question. The inner lining of stomach is protected by one of the following from hydrochloric acid. Choose the correct one
(a) Pepsin
(b) Mucus
(c) Salivary amylase
(d) Bile
Answer : B

ASSERTION AND REASON QUESTIONS

Following questions consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

Question. Assertion (A): Diffusion does not meet high energy requirements of multi-cellular organisms
Reason (R) : Diffusion is a fast process but occurs at the surface of the body.
Answer : C

Question. Assertion (A): The purpose of making urine is to filter out undigested food from intestine
Reason (R): Kidneys filter the waste and produce urine,
Answer : D

Question. Assertion (A): The inner lining of the small intestine has numerous finger-like projections called villi.
Reason (R) : The villi increase the surface area for absorption.
Answer : A

Question. Assertion (A) : Photosynthesis takes place in green parts of the plants.
Reason (R) : Photosynthesis always takes place in leaves.
Answer : C

Question. Assertion (A) : Ureters are the tubes which carry urine from kidneys to the bladder.
Reason (R): Urine is stored in the urethra.
Answer : C

Question. Pancreatic juice contains more than one enzyme. Which among the following combination is correct? 
(a) Pepsin and Lipase
(b) Amylase and Pepsin
(c) Pepsin and Trypsin
(d) Trypsin and Lipase
Answer : D

Question. Which one of the following organisms respires through the skin? 
(a) Blue whale
(b) Salamander
(c) Platypus
(d) Peacock
Answer : B

Question. The first enzyme that the food encounters in human digestive system is : 
(a) Pepsin
(b) Trypsin
(c) Chymotrypsin
(d) Amylase
Answer : D

Question. Red blood corpuscles are formed in 
(a) Liver
(b) Kidneys
(c) Small intestine
(d) Bone marrow
Answer : D

Question. The Excretory units of Annelids are: 
(a) Uniferous tubule
(b) Flame cells
(c) Nephridia
(d) Malpighian tubule
Answer : C

Question. Open circulatory system is found in: 
(a) Prawn
(b) Snakes
(c) Fish
(d) Man
Answer : A

Question. Haemoglobin is dissolved in Plasma of blood in: 
(a) Earthworm
(b) Roundworm
(c) Tapeworm
(d) Insects
Answer : A

Question. Which one of the following organisms has a cellular respiratory pigment dissolved in plasma and is also a predaceous carnivore and shows matriphagy? 
(a) Scorpion
(b) Cockroach
(c) Earthworm
(d) Sea cucumber
Answer : A

Question. Glucose is the prime source of energy in our body. However, it is stored in the form of glycogen in the muscle and liver of animals and in the form of starch in plants. As a result, everytime a cell requires glucose, it must hydrolyze glycogen which is an energy consuming process. Why does the cell store glycogen instead of glucose in free form? 
(a) Glycogen is more compact and more hydrophilic.
(b) Storage of glucose in free form will consume more ATP.
(c) Glucose in the free form creates more osmotic pressure.
(d) Glucose is highly reactive molecule hence storing in the free form can result in unwanted reactions in the cells.
Answer : C

Question. A squirrel was eating a fruit on the ground. Suddenly, it was attacked by a dog. The squirrel rushed to the tree immediately and saved itself from the dangerous attack. What immediate changes are most likely to have taken place in the body of the squirrel? 
A. Blood flows to the stomach for rapid digestion.
B. Adrenaline was secreted in the blood by the adrenal glands.
C. Heart beat becomes faster and pumps more blood so that muscles get more oxygen.
D. Adrenocorticotropic hormone is secreted in the blood and blood flows more towards the vital organs.
Select the correct combination of options given below:
(a) A and B
(b) A and C
(c) B and C
(d) C and D
Answer : C

Question. Removal of the pancreas impairs the breakdown of 
(a) lipids and carbohydrates only
(b) lipids and proteins only
(c) lipids, proteins and carbohydrates
(d) proteins and carbohydrates only
Answer : C

Question. Microscopic examination of a blood smear reveals an abnormal increase in the number of granular cells with multiple nuclear lobes. Which one of the following cell Types has increased in number? 
(a) Lymphocytes
(b) Monocytes
(c) Neutrophils
(d) Thrombocytes
Answer : C

Question. Which one of the following metabolic conversions requires oxygen? 
(a) Glucose to pyruvate
(b) Glucose to CO₂ and ethanol
(c) Glucose to lactate
(d) Glucose to CO₂ and H₂O
Answer : D

Question. Which one of the following organs is NOT a site for the production of white blood cells? 
(a) Bone marrow
(b) Kidney
(c) Liver
(d) Spleen
Answer : B

Question. Which of the following process occur only in animals? 
(a) Respiration
(b) Nutrition
(c) Nervous control
(d) Hormonal control
Answer : C

Question. Tricuspid valve is present in 
(a) Right atria and right ventricle
(b) Left atria and left ventricle
(c) Wall of atrium
(d) Wall of vetricle
Answer : A

Question. Root pressure is effective way transporting water in xylem. This pressure is generated 
(a) In bright sunlight
(b) During night
(c) At very low temperature
(d) In high trees
Answer : B

Question : Out of the four experimental set-up shown below, which one will demonstrate the evolution of carbon dioxide during respiration of germinating seeds ? 

a. III

b. II

c. IV
d. I

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 : Why are glomeruli considered as dialysis bags?
Answer : The main fimetion performed by the glomeruli is selective filtration. They filter small molecules containing glucose, salts, urea, and liquid senim. Etc. The large molecules such as proteins remain in blood. Thus, glomenili of the kidneys function as dialysis bags.

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 : 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 :  (i) Draw a well labeled diagram of human digestive system
(ii) Describe the role of following in digestion.
a) Bile
b) Salivary amylase
c) HCl
Answer : (i)a) Bile – emulsification of fats
b) Salivary amylase – digest starch in mouthc) HCl – Activate pepsinogen by making medium acidic in stomata.

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 from being damaged by HCl. Excessive secretion of HCl can damage the lining and lead to peptic ulcer.

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 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 : 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 eficient 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 : 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 : 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.

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 : 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 : 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 why?
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 : 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 : 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 : Leaves of a healthy potted plant were coated with petroleum jelly. How will it affect the plant? State two reasons.
Answer :The plant will not remain healthy for long due to the following reasons:-

1.There will be no transpiration.
2. There will be no exchange of gases which will affect the rate of photosynthesis.

Question : What will be the outcome if a farmer foods 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 : Name the areas in a woody stem through which respiratory exchange of gases take place.
Answer : In woody stem, the bark has lenticels for gaseous exchange.

Question : Autotrophs synthesis food for the living world. Justify this statement in one sentence only interconnecting autotrophs and heterotrophs.
Answer : The food producers are autotrophs and all the heterotrophs consume the food produced by the autotrophs directly or indirectly. 

Question. Choose the correct statement(s) amongst the following.       
(a) For regulating different life processes energy is required.
(b) Living organisms grow with time.
(c) Living organisms need to repair and maintain their structures.
(d) Molecules within the cells do not exhibit movement.
Answer : B

Question. Identify the correct path of urine in the human body.
(a) Kidney → urinary bladder → urethra → ureter
(b) Urinary bladder → ureter → kidney → urethra
(c) Kidney → ureter → urethra → urinary bladder
(d) Kidney → ureter → urinary bladder → urethra
Answer : D

Question. Coagulation of blood in a cut or wound is brought about by:
(a) plasma
(b) platelets
(c) WBC
(d) RBC
Answer : B

Question. The opening and closing of the stomatal pore depends upon
(a) Oxygen
(b) Temperature
(c) water in the guard cells
(d) concentration of CO₂
Answer : C

Question. Name the substances whose build up in the muscles during vigorous physical exercise may cause cramps?
(a) Ethanol + Carbon dioxide + Energy
(b) Lactic acid + Energy
(c) Carbon dioxide + Water + Energy
(d) Pyruvate
Answer : B

Question. The food in autotrophs is reserved in the form of       
(a) protein
(b) fatty acid
(c) glycogen
(d) starch
Answer : D

Question. Which of the following respiratory structures has cartilage rings to prevent it from collapsing?       
(a) Nasal cavity
(b) Pharynx
(c) Larynx
(d) Trachea
Answer : D

Question. Which of the following is the correct sequence representing human alimentary canal?    
(a) Mouth → oesophagus → stomach → small intestine → large intestine
(b) Mouth → small intestine → stomach → oesophagus → large intestine
(c) Mouth → stomach → oesophagus → small intestine → large intestine
(d) Mouth → stomach → oesophagus → large intestine → small intestine
Answer : A

Question. Pancreatic juice is carried by the pancreatic duct into              
(a) large intestine 
(b) liver
(c) duodenum
(d) stomach
Answer : C

Question. Which part of human cell is involved in conversion of pyruvic acid into lactic acid during deficiency of oxygen?       
(a) Golgi body
(b) Mitochondria
(c) Cytoplasm
(d) Lysosome
Answer : C

Question. Which of the following gases turns lime water milky when we blow air into it from mouth?       
(a) Oxygen
(b) Carbon dioxide
(c) Nitrogen
(d) Carbon monoxide
Answer : B

Question. Which of the following processes is responsible for cramps in the muscles of sportsmen?       
(a) Nonconversion of glucose to pyruvate
(b) Conversion of pyruvate to lactic acid due to deficiency of oxygen
(c) Conversion of pyruvate to glucose in presence of oxygen
(d) Conversion of pyruvate to ethanol
Answer : B

Question. What role is played by stomata during photosynthesis?
Answer : CO₂ enters the leaves and O₂ is released into air through stomata.

Question. Where is bile stored?
Answer : Gall bladder

Question. Name the organism which converts pyruvate to ethanol.
Answer : Yeast

Question. Where does the second stage of aerobic respiration take place?
Answer : Mitochondria

Question. Which type of organ is vermiform appendix?
Answer : Vestigial

Question. From where does a plant obtain water for photosynthesis?
Answer : Water is absorbed from soil.

Question. What is similar among animals, fungi and some bacteria?
Answer : They cannot prepare their own food.

Question : Why is transpiration important for plants?
Answer : Transpiration is important because:
(1) it helps in absorption and upward movement of water and minerals from roots to leaves.
(2) it prevents the plant parts from heating up.

Question :  What is mode of nutrition in fungi? 
Answer : In fungi, there is saprotrophic mode of nutrition. In this case organisms obtain foodfrom dead and decaying organic matter.

Question :  How does water reach upto the leaves ? 
Answer : Water is taken up by the roots and reaches the leaves through the xylem vessels which are a part of the vascular bundle.

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.

Question : In the experiment set up to show that “CO₂ is given out during respiration”, name the substance taken in the small test tube kept in the conical flask. State its function and the consequence of its use. 
Answer : The substance taken in a small test tube in the conical flask is Potassium Hydroxide or KOH. The KOH solution absorbs the evolved carbon dioxide released by germinating seeds during respiration. The absorption of all the released CO2 gas by KOH solution creates a partial vacuum in the conical flask due to which level of water rises up in the tube.

Question : Define parasitic nutrition. Name an organism having parasitic mode of nutrition.
Answer : Parasitic Nutrition: The parasitic nutrition is that nutrition in which an organism derives its food from the body of another living organism without killing it. Organisms having parasitic mode of nutrition are Plasmodium and round-worms.

Question : In which form do plants store the carbohydrates which are not used immediately?
Answer : Plants store carbohydrates which are not used immediately in the form of starch.

Question : How is the opening and closing of stomatal pore regulated in plants?
Answer : The opening and closing of stomatal pores is a function of guard cells. When water flows into guard cells, they swell up causing the stomatal pore to open. When the guard cells shrink, the pore closes.

Question : If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? Justify your answer. 
Answer : If the plant shows evidence that it is releasing CO2 during the day and taking in oxygen, it does not mean that there is no photosynthesis taking place in the plant. Instead, it suggests that the plant is undergoing photosynthesis at a very low rate. In a normal scenario, the rate of respiration is higher during night while it is slower during the day. The CO₂ produced during night time is utilized by the plant during the day to perform photosynthesis. 

Short Answer

Question : What is photosynthesis? Explain its mechanism.
Answer : Photosynthesis– A process in which green plants takes carbon dioxide and water and converts them into carbohydrates in the presence of sunlight and chlorophyll.

Mechanism:
(i)Absorption of light energy by chlorophyll.
(ii)Conversion of light energy to chemical energy.
(iii)Splitting of water molecules (H₂O) into hydrogen and oxygen.
(iv)Reduction of carbon dioxide to carbohydrate.

Long Answer

Question : Answer the following:
(A) What would happen if all the green plants disappear from the earth?
(B) If a plant is releasing carbon dioxide and taking in oxygen during the day, does it mean that there is no photosynthesis occurring? justify your answer.
Answer :  (A) Green plants are the sources of energy for all organisms. If all green plants disappear from the earth, all the herbivore will die due to starvation and so will the carnivores.
Since autotrophs are the only organisms that can fix the atmospheric carbon dioxide into organic compounds, these organisms occupies first trophic level in food chain and serve as source of food and energy for all other organisms of higher trophic evels (heterotrophs/consumers). Hence, in absence of these plants, whole functioning of whole ecosystem will come to a halt due to lack of food and energy source for consumers (herbivores, carnivores and omnivores)
(B) Respiration is the process of oxidation of food substances that release carbon dioxide; it takes place throughout the day. Photosynthesis is the process of fixing the atmospheric carbon dioxide into organic compounds (carbohydrates) with release of oxygen gas as by product. Photosynthesis takes place during the day in presence of Sunlight only.
The CO₂ released during respiration is absorbed by plants for photosynthesis during day causing net release of oxygen only. If a plant is releasing carbon dioxide and taking in oxygen during the day, it means that either rate of photosynthesis is too slow to counter balance the release of CO₂ by respiration or photosynthesis is not taking place at all.