CBSE Class 10 Science Life Processes Assignment Set B

MCQ Questions for NCERT Class 10 Science Life Processes

Question : The organism having parasitic mode of nutrition is:
(a) Penicillium
(b) Plasmodium
(c) Paramecium
(d) Parrot

Answer : B

Question. Single circulation, i.e., blood flows through the heart only once during one cycle of passage through the body, is exhibited by which of the following:
(a) hyla, rana, draco
(b) whale, dolphin, turtle
(c) labeo, chameleon, salamander
(d) hippocampus, exocoetus, anabas

Answer : D

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 contraction and expansion movement of the walls of the food pipe is called:
(a) translocation
(b) transpiration
(c) peristaltic movement
(d) digestion

Answer : C

Question. When a few drops of iodine solution are added to rice water, the solution turns blue- black in colour. This indicates that rice water contains:
(a) fats
(b) complex proteins
(c) starch
(d) simple proteins

Answer : C

Question. The exit of unabsorbed food material is regu-lated by
(a) liver
(b) anus
(c) small intestine
(d) anal sphincter

Answer : D

Question. What are the products obtained by anaerobic respiration in plants?
(a) Lactic acid + Energy
(b) Carbon dioxide + Water + Energy
(c) Ethanol + Carbon dioxide + Energy
(d) Pyruvate

Answer : C

Question. The breakdown of pyruvate to give carbon di-oxide, water and energy takes place in
(a) cytoplasm
(b) mitochondria
(c) chloroplast
(d) nucleus

Answer : B

Question. Glycolysis process occurs in which part of the cell?
(a) Cytoplasm
(b) Nucleus
(c) Mitochondria
(d) Chloroplast

Answer : A

Question. Which part of nephron allows the selective reabsorption of useful substances like glucose, amino acids, salts and water into the blood capillaries?
(a) Tubule
(b) Glomerulus
(c) Bowman’s capsule
(d) Ureter

Answer : A

Question. Which of the following events in the mouth cavity will be affected if salivary amylase is lacking in the saliva?
(a) Starch breaking down into sugars.
(b) Proteins breaking down into amino acids.
(c) Absorption of vitamins.
(d) Fats breaking down into fatty acids and glycerol.

Answer : A

Question. The respiratory pigment in human beings is:
(a) carotene
(b) chlorophyll
(c) haemoglobin
(d) mitochondria

Answer : C

Question. Where is the dirty blood in our body filtered?
(a) Heart
(b) Lungs
(c) Ureter
(d) Kidneys

Answer : D

Question. Which of the following statements is not correct?
(a) Deoxygenated blood is poured into right atrium of heart.
(b) The excretory units of flatworms are flame cells.
(c) Human kidney has about 1 million nephridia
(d) Tracheids and vessels are non-living conducting tissues.

Answer : C

Question. The movement of food in phloem is called:
(a) transpiration
(b) translocation
(c) respiration
(d) evaporation

Answer : B

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

Answer : B

Question. Name a circulatory fluid in the human body other than blood.
(a) Platelets
(b) RBC
(c) Lymph
(d) Plasma

Answer : C

Question. Which region of the alimentary canal absorbs the digested food?
(a) Stomach
(b) Small intestine
(c) Large intestine
(d) Liver

Answer : B

Question. Name the pores in a leaf through which respi-ratory exchange of gases takes place.
(a) Lenticels
(b) Vacuoles
(c) Xylem
(d) Stomata

Answer : D

Question. Which of the following are chiefly digested in the stomach?
(a) Carbohydrates
(b) Proteins
(c) Lipids
(d) Fats

Answer : B

Question. Name the tube which connects the kidneys to the urinary bladder.
(a) Urethra
(b) Nephron
(c) Tubule
(d) Ureter

Answer : D

Question : Rings of cartilage present in the throat ensure that
(a) the air passage collapses
(b) the air passage does not collapse
(c) the air is filtered entering the nostrils
(d) None of these

Answer : B 

The correct record, out of these, is that of student : 

(a) A

(b) C

(c) B

(d) D

 

Answer : A

Explanation: Stomatal pore is grounded by guard cell.

Question : Which of the following statements is incorrect about artery?
(a)It carries oxygenated blood from heart to different body parts.
(b)It is also called collecting vessel
(c)It is thick, elastic and muscular
(d)It has no valves.

Answer : B

 

Cct Questions:

I. There is a range of strategies by which the food is taken in and used by the organisms in heterotrophic nutrition. Some organism breakdown the food material outside the body and then absorb it. Others take in whole material and break it down inside their bodies. What an be taken in and broken down depends on the body design and functioning. Some others derive nutrition from plants and animals without killing them.

Question : Organisms which derive nutrition from plants and animals without killing them.
A. Parasites
B. Saprophytes
C. Heterotrophs
D. Autotrophs
Answer : A

Question : In which part of amoeba complex food particles are broken down into simpler ones.
A. Cytoplasm
B. Pseudopodia
C. Nucleus
D. Food vacuole
Answer : D

Question : Which of the following is an example of saprotroph.
A. Cuscuta
B. Sugarcane
C. Bread mould
D. Amoeba
Answer : C

Question : Taking in whole material and breaking it down inside the body is
A. Parasitic nutrition
B. Holozoic nutrition
C. Saprophytic nutrition
D. Symbiosis
Answer : B

Question : Heterotrophic nutrition involves
A. Production of simple sugar from inorganic compounds
B. Utilisation of chemical energy to prepare food
C. Utilisation of energy obtained by plants
D. All of these
Answer : C

 

Important Questions for NCERT Class 10 Science Life Processes

Very Short Answer type Questions

Question. Name four nutrients needed by the plants which are taken up from the soil.
Answer: Nitrogen, phosphorus, iron, and magnesium.

Question. Name the activity of living beings which considered as indication of life?
Answer: Movement.

Question. Classify the followings as saprotrophs or parasites: leech, yeast, mushroom
Answer: Saprotrophs : yeast, mushroom
Parasites : leech

Question. What is alimentary canal?
Answer: It is a long tube extending from mouth to anus in which digestion and absorption of food takes place.

Question. Name the cell organelle in which photosynthesis occur.
Answer: Chloroplast

Question. Mention how organisms like bread moulds and mushrooms obtain their food.
Answer: Organisms like bread moulds and mushrooms break down the food materials outside the body and then absorb it.

Question. Name the process by which plants prepare food.
Answer: Photosynthesis

Question. Name the basic requirement of living organisms needed to obtain energy.
Answer: Food

Question. In which part of alimentary canal digestion does not occur?
Answer: Large intestine

Question. Mention the raw materials required for photosynthesis. 
Answer: The raw materials required for photosynthesis are carbon dioxide and water in presence of sunlight and chlorophyll.

Question : How is small intestine designed to obsorts digested food?
Answer : The inner living of the small intestine has numerous finger-like projections called villi which increase the surface area for absorption. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body, where it is utilised for obtaining energy, building up new tissues and repair of old tissues. 

Question : How is the wall of small intestine adapted for performing the function of absorption of food?
Answer : The inner lining of the small intestine has numerous finger-like projections called villi which increase the surface area for absorption.

Question : Name thin walled air sacs of the lungs. 

Answer : Each small tube ends in clusters of thin-walled air sacs, called alveoli. It is the alveoli that receive the oxygen and pass it on to the blood

Question : Why is there a difference in the rate of breathing between aquatic organisms and terrestrial organisms? Explain. 
Answer :  Rate of breathing is different between aquatic and terrestrial organisms. Terrestrial organisms can breathe the oxygen which is present in the atmosphere, but animals that live in water use the oxygen dissolved in water. Since the amount of dissolved oxygen in very low as compared to amount of oxygen in the air. Hence, the rate of breathing in aquatic organisms is much faster than terrestrial organisms.

Question : What are the end products formed during fermentation in yeast? under what conditions a similar process takes place in our body that leads to muscle cramps? 
Answer : Fermentation of yeast or anaerobic respiration is defined as the kind of respiration that takes place in the absence of oxygen. The end products formed during this kind of respiration are: ATP, ethanol and carbon dioxide. When such a similar process takes place in our body, the muscles get tired easily. This happens because of the accumulation of lactic acid formed due to anaerobic respiration.

Question : Mention any three methods adopted by plants to minimise the transpiration rate. 

Answer : Three methods adopted by plants to minimize the rate of transpiration are:

i. In some cases leaves are rolled to cover stomata (e.g. some grasses)

ii. The stomata may be sunken (e.g. Nerium)

iii. In some cases, leaves may be dropped or absent as in most cacti.

Short Answer type Questions

Question : Explain the ways in which glucose is broken down in absence or shortage of oxygen.
Answer : The first step in breakdown of the -carbon molecule glucose takes place in the cytoplasm of cells of all organism and we obtain a 3- carbon molecule compound called pyruvate.
Further pathway for breakdown of this pyruvate depends on the amount of oxygen available which are given below:
(1) Anaerobic Respiration takes place in the absence of oxygen. In this process the pyruvate is converted into ethanol and carbon dioxide. For example in yeast during fermentation.
(2) Lack of Oxygen: When there is a lack of oxygen in our body, the pyruvate is converted into lactic acid, which is a 3-carbon molecule, and energy. This takes place in our muscles during vigorous exercise or activity.

Question : A student has set up an apparatus to show that ‘‘CO₂ is released during respiration. After about 1 hour he observes no change in the water level in the delivery tube. Write two possible reasons for the failure of the experiment. 
Answer : Two possible reasons for the failure of the experimental set up to show that ‘‘CO₂ is released during respiration’’:
(1) The germinating seeds could be dry.
(2) The conical flask may not be air tight.
(3) Freshly prepared solution of KOH is not used.
(4) The longer end of the bent glass tube may not be fully dipped in the coloured water in the beaker.

Question : What is transpiration? List its two functions.
Answer : The loss of water in the form of vapour from aerial parts/leaves/stems is known as transpiration.
Functions:
(i)It helps in the absorption and upward movement of water.
(ii)Movement of dissolved minerals from root to leaves.
(iii)It helps in the temperature regulation or cooling of the plant.

Question : How do carbohydrates, proteins and fats get digested in human.
Answer : (i) Carbohydrates: -The human saliva contains an enzyme called salivary amylase which digests starch. In duodenum, pancreatic juice which contains digestive enzymes like pancreatic amylase breaks down the starch. It is digested in jejunum by intestinal juice.
(ii)Protein-In stomach, proteins are digested by gastric juice. The enzyme pepsin breaks down proteins into amino acid and in jejunum by intestinal juice which contain trypsin. It also convert protein into amino aci(d)
(iii)Fats-In duodenum and jejunum fats are digested by pancreatic juice aided by bile salts.

Question : Give reasons:
(A) Ventricles have thicker muscular walls than atria.
(B) Transport system in plants is slow.
(C) Circulation of blood in aquatic vertebrates differs from that in terrestrial vertebrates.
(D) During the daytime, water and minerals travel faster through xylem as compared to the night.
(E) Veins have valves whereas arteries do not. 
Answer : (A) Ventricles have thicker muscular walls than atria because they have to pump blood into various organs.
(B) Transport system in plants is slow because:
(1) Plants have low energy needs as
(2) Plant bodies have a large proportion of dead cells in many tissue.
(3) Plants do not move
(C) Aquatic vertebrates like fish have a two chambered heart (which consists of one atrium and one ventricle). The heart pumps deoxygenated to the gills and it gets oxygenated in the gills. The oxygenated blood from the gills is supplied to the body parts. Thus, blood goes only once through the heart in the fish during one cycle of passage through the body.
But in terrestrial organisms, heart may be 3 or 4 chambered, blood gets oxygenated in the lungs and most of them have double circulation

Long Short Answer type Questions

Question : (a)Draw a sectional view of the human heart and label on it Aorta, right ventricle, pulmonary vein, pulmonary artery
(b)Explain the process of double circulation.
Answer :  (a)