Life Processes Class 10 Science Exam Questions

Exam Questions Class 10

Please refer to Life Processes Class 10 Science Exam Questions provided below. These questions and answers for Class 10 Science have been designed based on the past trend of questions and important topics in your class 10 Science books. You should go through all Class 10 Science Important Questions provided by our teachers which will help you to get more marks in upcoming exams.

Class 10 Science Exam Questions Life Processes

Class 10 Science students should read and understand the important questions and answers provided below for Life Processes which will help them to understand all important and difficult topics.

Very short Answer:

Question: Where does digestion of fats take place in our body?
 Digestion of fats takes place in small intestine.

Question: What will happen to a plant if its xylem is removed? 
 Xylem is the main water conducting tissue of plant. If it is removed then water and minerals absorbed by plant roots will not be able to reach different plant parts and plant will wilt and ultimately die.

Question. Give the energy transformation that takes place in the process of photosynthesis ?
Answer : During the process of photosynthesis, solar energy is converted into chemical energy.

Question. How is O2 and CO2 transported in human beings ?
Answer : Oxygenated blood containing oxygen (O2) content is transported in human beings by the arteriesor by haemoglobin of red blood corpuscles. The  deoxygenated blood containing carbon-dioxide (CO2) content is carried by the veins or by plasma of the blood.

Question. Name the raw materials needed by green plants for photosynthesis ?
Answer : Carbon dioxide and water are the raw materials needed by green plants for photo-synthesis.

Question. Give the chemical equation for photosynthesis ?
Answer :

Question. The pharynx leads to trachea as well as to the oesophagus. The two openings lie very close to each other. Yet the food we swallow does not normally go to trachea. Why ?
Answer : The opening of trachea is guarded by a muscular flap like structure called epiglottis. When we swallow our food it closes the opening of trachea thus food goes into oesophagus and not to trachea.

Question. In the experimental 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 chemical kept in the test tube is KOH–Potassium Hydroxide. The function of this chemical is to absorb the vapours of CO2.
Consequence : The water level rises in the test tube dipped in beaker and partial vacuum is created.

Question. How can we destarch a plant ?
Answer : A plant can be destarched by placing it in dark for 24– 48 hours.

Question. Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds ?
Answer : Mammals and birds are warm blooded animals so they need to maintain their constant body temperature and they need more energy to maintain their body temperature. The separation of oxygenated and deoxygenated blood allows highly efficient supply of oxygen to the body thus they get more energy which helps them in maintaining their body temperature.

Question. What are the end products of aerobic respiration ?
Answer : The end products of aerobic respiration are carbon dioxide and water.

Question. Why is energy required by an organism even during sleep ?
Answer : Even though an organism is asleep, various biological activities like respiration, circulation, digestion etc., occurs in the body which needs energy.

Question. Why does our blood look red ?
Answer : Blood contains haemoglobin which is an oxygen carrying pigment that makes the blood look red.

Question: Write one function of each of the following components of the transport system in human beings.
(a) Blood vessels (b) Blood platelets (c) Lymph (d) Heart 

Answer: (a) : The blood vessels are tubes that transport blood throughout the body. There are three kinds of blood vessels in human body; arteries, veins and capillaries.
(b) Blood platelets are irregular disc shaped cytoplasmic fragments that assist in formation of blood clot at the site of injury and prevent excessive loss of blood.
(c) Lymph is a mobile connective tissue and acts as ‘middle man’. It takes part in nutritive process as it carries protein molecules from tissue into the blood stream. It also helps in removing waste products like fragments of dead cells, germs, etc.
(d) Human heart is a muscular organ that pumps blood throughout the body via the circulatory system, supplying oxygen and nutrients to the tissues and removing carbon dioxide and other wastes from the same.

Short Answer:

Question: List in tabular form three distinguishing features between autotrophic nutrition and heterotrophic nutrition.
Answer :

Life Processes Class 10 Science Exam Questions

Question: What is transpiration ? List its two functions.
Answer : The evaporation of water from the leaves of a plant is called transpiration.
Functions of transpiration :
(a) It helps in the upward movement of water and minerals from root to the leaves through the stem and in the absorption.
(b) Helps in cooling the plant surface.

Question: (a) State the role played by the following in the process of digestion.
(i) Enzyme trypsin
(ii) Enzyme lipase
(b) List two functions of finger like projections present in the small intestine.
Answer : (a) (i) Trypsin is an enzyme that helps in the digestion of proteins. In the small intestine, trypsin breaks down proteins, continuing the process of digestion that began in the stomach. It may also be referred to as a proteolytic enzyme, or proteinase. Trypsin is produced by the pancreas in an inactive form called trypsinogen. The trypsinogen enters the small intestine through the common bile duct and is converted into active trypsin. This active trypsin acts with the other two principal digestive proteinases namely pepsin and chymotrypsin, to breakdown dietary protein into peptides and amino acids. These amino acids are essential for muscle growth, hormone production and other important bodily functions. 
(ii) Lipase enzyme breaks down dietary fats into smaller molecules known as glycerol and fatty acids. A little quantity of lipase, known as gastric lipase is produced by the cells of the stomach. This enzyme mainly digests fat present in the food. The pancreas is the primary source of lipase in the digestive tract, which produces pancreatic lipase which acts in the small intestine. The bile produced in the liver and liberated in the intestine transform dietary fat to smaller fat globules. Pancreatic lipase acts on these fat globules and converts them into glycerol and fatty acids that are small, energy molecules. Glycerol and fatty acids move in blood and lymph vessels to move in every part of the body.
(b) The inner surface of the small intestine has numerous finger-like projections called villi which increase the surface area for rapid absorption of digested food. The digested food which is absorbed through the walls of the small intestine goes into our blood.

Question: Write two different ways in which glucose is oxidized to provide energy in human body. Write the products formed in each case.
Answer : Glucose is oxidised in two forms to provide energy to the body

Life Processes Class 10 Science Exam Questions

This is an example of aerobic respiration that happens in presence of oxygen.

Life Processes Class 10 Science Exam Questions

This is an example of anaerobic respiration.

Question: (a) What is translocation ? Why is it essential for plants ?
(b) Where do the substances in plants reach as a result of translocation ?
Answer : (a) The transport of food from leaves to other parts of the plant is called translocation. Translocation
is essential for plants because without it food prepared by the leaves cannot reach other parts of
the plant for their growth and development.
(b) The substances in plants reach to other tissues in plants from the leaves, fruits, seeds and other growing organs as a result of translocation.

Question: What would happen if green plants disappear from earth ?
Answer : Green plants are autotrophs i.e., they prepare their own food. All herbivores and carnivores depend directly or indirectly on green plants for their food. Herbivores directly eat plants and if green plants would not be there, they will die of starvation. Similarly, carnivores eat herbivores, if herbivores will die so naturally carnivores will also die. Green plants release oxygen to atmosphere by photosynthesis which is a life supporting gas. So, in short we can say, without green plants there may not be any chance for existence of living things.

Question: Define the term transpiration. Design an experiment of demonstrate this process.
Answer :
Loss of excess water from the leaves of plants with the help of stomata is called as transpiration.
Transpiration Experiment
Material Required :
A potted plant, A polythene, Tape

Life Processes Class 10 Science Exam Questions

(a) Take a potted plant and enclose the leaves of the plant with a big plastic or polythene bag.
(b) Now keep the plant in sunlight for two hours.
(c) After sometime you will be observe the water droplets on the polythene sheet.
(d) It depicts the loss of water from the leaves of the plant depicting transpiration.

Question: List two types of the transport system in human beings and write the functions of any one of these.
Answer : Lymphatic system and blood circulatory system are two types of the transport system in human beings.
Functions of blood circulatory system :
(a) It carries nutrients and oxygen to all cells in the body.
(b) Removes CO2 from the body cells.
(c) It carries digested food from the small intestine to other parts of the body.
(d) It carries hormones from endocrine glands to different organs fo the body.

Question: How are fats digested in our bodies ? Where does this process take place ?
Answer : The complete digestion of fats occurs in small intestine. Bile juice secreted by liver acts upon large fats to convert them into small globules by the process of emulsification. Lipase enzyme secreted by pancreas  acts upon lipids to convert them into fatty acids and glycerol.

Question: Write three types of blood vessels. Give one important feature of each. 
Answer : The three types of blood vessels are :
(a) Arteries
(b) Veins
(c) Capillaries
(a) Arteries : They carry oxygenated blood from the heart and transport it to organs.
(b) Veins : They carry deoxygenated blood from rgans and take this blood to the heart.
(c) Capillaries : Arteries and veins divide to form arterioles and venules. The nutrients, hormones and gases can diffuse into the tissue cells through the walls of capillaries and vice-versa.

Question: Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans?
Answer : Unicellular organisms have only one cell and they do not have any specific organs for diffusion of gases. The cell itself is in direct contact with the environment so they can get oxygen easily by simple diffusion process. But in multicellular organisms large number of cells, tissues and organs are present which are not in direct contact with the environment. So, the requirement of oxygen by each and every cells cannot be fulfilled by simple diffusion process quickly. It has been estimated that in human beings a period of three years is needed to carry a molecule of oxygen from head to toe, if oxygen moves from one cell to another through diffusion process.

Question: What criteria do we use to decide whether something is alive ?
Answer : The following criteria decides whether something is alive :
(a) Movement and growth : All living organisms show movement like running, walking. They also show growth. They require energy for cell repair and replacement.
(b) Nutrition : They require food to derive energy in order to carry out their metabolic activities.
(c) Respiration : They inhale oxygen to break down glucose to release energy. During this process they exhale carbon dioxide.
(d) Reproduction : They reproduce to give birth to their new ones.
(e) Excretion : They eliminate waste products in the form of urine, faeces, etc., from their body.

Question: Name the following :
(a) Mode of nutrition of the cuscuta plant.
(b) First form of food substance produced during photosynthesis.
(c) Organisms which live on or inside the body of another organism and depend on it for food.
(d) Small openings present on leaf surface.
Answer : (a) Parasitic mode of nutrition(b) Glucose
(c) Parasites (d) Stomata

Question: What are outside raw materials used by an organism ?
Answer : The important outside raw materials used by an organism are :
(a) Carbon dioxide, water and mineral nutrients are needed by autotrophic plants. 
(b) Organic nutrients are required by heterotrophic organisms.
(c) Oxygen is used for respiration by both autotrophs and heterotrophs for oxidation of glucose to release chemical energy in form of ATP.

Question: Draw the structure of human excretory system labelling the following :
(a) The structures in which urine is formed.
(b) Structures in which urine is stored
(c) The blood vessel supplying oxygenated blood to kidneys.
(d) The structure through which urine passes out from the body.
Answer :(a) Kidneys
(b) Urinary bladder
(c) Renal artery
(d) Urethra

Life Processes Class 10 Science Exam Questions

Question: What are the differences between aerobic and anaerobic respiration ? Name some organisms that use the anaerobic mode of respiration ? 
Answer :

Life Processes Class 10 Science Exam Questions

Some organisms that use the anaerobic mode of respiration are yeast, some bacteria, some parasitic worms, etc.

Question: Draw a well labelled diagram of :
(a) Chloroplast
(b) Open and closed stomata
Answer : (a)

Life Processes Class 10 Science Exam Questions

Question: What are the differences between transport of materials between xylem and phloem ?
Answer :

Life Processes Class 10 Science Exam Questions

Question: Draw a labelled diagram of the experimental set up for the study of liberation of carbon dioxide gas during respiration.
Answer :

Life Processes Class 10 Science Exam Questions

Question: How are oxygen and carbon dioxide transported in human beings? How are lungs designed to maximise the area for exchange of gases? 
Answer: In gaseous exchange, the blood takes up oxygen from the alveolar air and releases CO2 to the alveolar air. Such an exchange occurs because the concentration of O2 is more in alveolar air and O2 moves from higher concentration to lower concentration due to the process of diffusion. The blood has more concentration of CO2 as compared to alveolar air.  This, the CO2  moves from blood to alveolar air due to simple diffusion. This exchange
of gases results in the oxygenation of blood. In times, the exchange of gases occurs between the oxygenated blood and the tissue cells. The concentration of O2 is more in the blood and less in the tissue cells. So, the O2 moves from blood to the tissues and CO2  moves from tissues to the blood. The blood now becomes deoxygenated.
Heart receives this oxygen rich blood from lungs through pulmonary vein and distributes it to all body parts through arteries and collect carbon dioxide rich blood from all body parts through veins and takes it to lungs through pulmonary artery for oxygenation. Deoxygenated carbon dioxide rich air moves out from blood capillaries into the alveoli and is finally breathed out. Human lungs have a highly branched network of respiratory tubes. A primary bronchus divides into secondary bronchus, which in turn forms tertiary bronchus. Tertiary bronchus divides repeatedly into bronchioles which finally terminate into alveoli. Alveoli are small, rounded polyhedral pouches which are extremely thin-walled and possess a network of capillaries. Exchange of gases takes place in alveoli and hence an alveolus is called a miniature lung. The alveoli provide a vast surface area where exchange of gases can takes place. Oxygen diffuses from alveoli into pulmonary blood capillaries and CO2 diffuses out from capillaries into alveoli.

Question: (a) What are two difiernt ways in which glucose is oxidised to provide energy in various organisms?
(b) Write any two difierences between the two ways of oxidation of glucose in organisms.

Answer: (a) Oxidation of food (glucose) within cell may be of two types depending upon the availability of atmospheric oxygen : aerobic respiration and anaerobic respiration. (i) Aerobic respiration : The oxidative breakdown of respiratory substrates with the help of atmospheric O2 is known as aerobic respiration. During this process, the respiratory substrate (glucose) is completely broken down into carbon dioxide and water by the process of oxidation and large amount of energy (38 ATP) is produced.
Aerobic respiration includes glycolysis which is common to both aerobic and anaerobic respiration. The pyruvic acid (pyruvate) molecules formed during glycolysis are carried to the mitochondria where they completely break down to CO2 and H2O with the evolution of a large amount of energy. 

Life Processes Class 10 Science Exam Questions

(ii) Anaerobic respiration: Oxidation of respiratory substrates in absence of oxygen is termed as anaerobic respiration. It involves incomplete breakdown of respiratory substrates in which the end products, such as ethanol or lactic acid are formed and small amount of energy is released. It involves glycolysis, during which glucose is degraded into pyruvate.
Further breakdown of pyruvic acid in absence of oxygen result in the production of ethanol or lactic acid. Anaerobic oxidation of glucose in microorganisms formed ethanol and CO2 and in muscle cells of humans, glucose is naerobically metabolised into lactic acid.

Life Processes Class 10 Science Exam Questions

Long Answer:

Question: Explain the mechanism of photosynthesis.
Answer : Photosynthesis is the biological process in which autotrophs prepare their own food. The process of photosynthesis occurs in two phases–Photochemical phase and Biosynthetic phase.
The overall photosynthesis process can be represented in the form of a chemical reaction as :

(a) Photochemical phase or Light dependent phase : It occurs in thylakoid or grana of chloroplast. Chlorophyll molecules absorb sunlight energy
which leads to photolysis of water molecule. The hydrogen produced due to splitting of water is carried by NADP forming NADPH. Oxygen is produced as byproduct during this phase.
(b) Biosynthetic phase or Light independent
phase : It occurs in stroma of chloroplast. This phase does not require light. Here carbon dioxide is converted to glucose using energy molecule ATP and NADPH.

Question: (a) Mention any two components of blood.
(b) Trace the movement of oxygenated blood in the body.
(c) Write the function of valves present in between atria and ventricles.
(d) Write one structural difference between the composition of artery and veins.
Answer : (a) Red blood cells and white blood cells are the components of blood.
(b) The oxygenated blood goes into the left atrium from there it goes to the left ventricle and then to all the body organs.
(c) Valves prevents the backflow of blood from the ventricles to the atrium.
(d) Walls of arteries are thick and they carry oxygenated blood whereas walls of vein are thin and they carry deoxygenated blood.

Question: (a) Write the correct sequence of steps followed during journey of oxygen rich blood from lungs to various organs of human body.
(b) What happens when the system of blood vessels develop a leak ?
Answer : (a) (i) Oxygenated blood from lungs enters through the pulmonary vein into left atrium.
(ii) The left atrium relaxes while collecting the oxygenated blood. Then the left atrium contract and the blood goes into left ventricle.
(iii) The left ventricle relaxes while receiving the oxygenated blood then it contracts and the blood flows into different organs and parts of the body.
(iv) The deoxygenated blood from different parts of the body enters the right atrium through superior and inferior vena cava.
(v) The right atrium contract and the blood flows into right ventricle.
(vi) The right ventricle relaxes while receiving the deoxygenated blood then it contracts and the blood flows into lungs for oxygenation through pulmonary artery.
(b) Leakage would lead to a loss of pressure which would reduce the efficiency of the pumping system. To avoid this, the blood has platelet cells which circulate around the body and plug these leaks by helping to clot the blood at these points of injury.

Question: Explain the digestion process in human beings.
Answer : Carbohydrates, proteins and fats present in food are digested in different parts of the alimentary canal as follows :
(a) Mouth : Salivary glands are present in mouth which secretes saliva that contains the enzyme salivary amylase or ptyalin. Ptyalin acts upon starch to convert into maltose.
Starch + Salivary amylase → Maltose 
(b) Oesophagus : No digestion occurs in this part.
Only food in form of bolus passes through it by peristalsis to reach the stomach.
(c) Stomach : Gastric glands present in stomach secrete pepsin which is a protein digestive enzyme. Proteins + Pepsin → Peptones and Proteoses
(d) Small intestine : It receives bile juice from liver, pancreatic juice from pancreas and intestinal juice secreted by intestine.
Bile helps in emulsification of fats so that lipase enzyme can easily acts upon fats to convert into fatty acids and glycerol.
Bile → Emulsified fats + Lipase → Fatty acids + Glycerol
Trypsin found in pancreatic juice acts upon peptones and proteoses and converts to peptides.
Trypsin + Peptones → Peptides
The complete digestion of carbohydrates to
glucose, proteins to amino acids and lipids to fatty acids and glycerol is done by intestinal juice in small intestine.
(e) Large intestine : It receives the undigested and
unabsorbed food from small intestine. Most of the water is absorbed here and the remaining is converted into a semi-solid waste material called faecus. The faecal matter is stored in rectum and is removed through anus from time to time.

Question: Describe the structure and functioning of nephrons ?
Answer : Structure of nephron : Nephron is the structural and functional unit of life. It has the following parts :
(a) Bowman’s capsule : It is a thin walled cup like structure which contains a knot like mass of blood capillaries called glomerulus. Both Bowman’s capsule and glomerulus are together called malpighian capsule.
(b) Proximal convoluted tubule : It is a convoluted region found near Bowman’s capsule.
(c) Loop of Henle : It lies next to proximal convoluted tubule which is U shaped structure.
(d) Distal convoluted tubule : It is the end part of the nephron which opens to collecting duct.

Functions of nephron : The formation of urine occurs in three steps :
(a) Ultrafiltration : Blood flows under high pressure in glomerulus and the liquid portion of the blood filter out from glomerulus and passes to the cup shaped cavity of Bowman’s capsule and this process is called ultrafiltration.
(b) Selective reabsorption : It is the process of selective absorption of useful substances like glucose, water, some salts etc., from glomerular filtrate which is obtained from ultrafiltration by different parts of nephron.
(c) Tubular secretion : Some harmful substances like chemicals, drugs like penicillin, potassium ions etc., are released by renal tubule to the forming urine called tubular secretion.

Question: How are water and minerals transported in plants ?
Answer : Water and minerals are transported in plants by xylem. Water containing minerals is called sap which is carried by xylem vessels to all parts of the plant from the roots. Root hairs absorb water from the soil by the process of osmosis whereas mineral salts are absorbed from the soil by the process of active transport. Water and minerals absorbed by the root hairs passes from cell to cell through epidermis, root cortex, endodermis and root xylem. The xylem vessels of the root of the plant are connected to xylem vessels of the stem so water passes from root to stem and finally to leaves. Water is used up for photosynthesis and some of water is also lost through leaves by the process of transpiration. The pressure at the xylem vessels of leaves is reduced due to transpiration so it creates a suction force and water rises from xylem vessels of stems and roots thus forming a continuous flow of water and mineral salts.

Question: Explain the nutrition process in amoeba.
Answer : Amoeba follows holozoic nutrition. It involves the following steps :
(a) Ingestion : Amoeba engulfs the food by using its temporary finger like projections called pseudopodia. This process is called ingestion.
(b) By phagocytosis process it engulfs its food.
(c) Digestion : The food which is taken inside the amoeba forms a food vacuole. Many enzymes are secreted into the food vacuole and the complex food molecule is converted into simple and diffusible form.
(d) Absorption and assimilation : The digested food is absorbed by the cell by diffusion process.
(e) Egestion : The undigested residue which remains in vacuole is expelled out.

Question: Describe the process of urine formation in kidneys.
Answer : Urine formation occurs in three steps :
(a) Ultrafiltration : Blood containing nitrogenous wastes flows with a great pressure through glomerulus. The liquid portion of the blood gets filtered through glomerulus and collects in the Bowman’s capsule which is called glomerular filtrate. This process is called ultrafiltration.
(b) Selective reabsorption : The glomerular filtrate contains a lot of useful substances like glucose, water, salts etc., which gets selectively reabsorbed by different parts of renal tubule. This process is called selective reabsorption.
(c) Tubular secretion : Distal convoluted tubule part of nephron secretes some harmful substances like salts, antibiotics like penicillin etc., to the forming urine which is called tubular secretion.
The formed urine is then received by collecting ducts which pours into the pelvis of kidney.

Question: Describe the three pathways of break down of glucose.
Answer : Glucose is break down to release energy in presence of oxygen as well as in absence of oxygen.
(a) Aerobic respiration : Here glucose is completely oxidized in presence of excess supply of oxygen. 
In human beings glucose is first break down to pyruvic acid in cytoplasm by the process of glycolysis releasing only 2 ATP molecules. Then pyruvate in mitochondria by Kreb’s cycle process completely break down to release carbon dioxide and water. Total 38 molecules of ATP are released during this process.
(b) Anaerobic respiration : It takes place in absence of oxygen. Pyurvate gets converted to lactic acid and carbon dioxide under anaerobic conditions mainly in muscles cells during strenuous exercise. In yeast pyruvate gets converted to ethanol and carbon dioxide by the process of fermentation.

Question: Draw a neat and labelled diagram of human respiratory system. Explain in brief the role of lungs in the exchange of gases.
Answer: The labelled diagram of human respiratory system is as follows: 

Life Processes Class 10 Science Exam Questions

The primary organs of the respiratory system are lungs, which function to take in oxygen and expel carbon dioxide as we breathe. During the exchange of gases at the respiratory surface (alveoli) of the respiratory organs (lungs) and the oxygen enters the blood and combines with haemoglobin (respiratory pigment) of red blood corpuscles to form oxyhaemoglobin. The oxygenated blood from the lungs is carried to left atrium of heart by pulmonary veins. The heart pumps and distributes the oxygenated blood to the body tissues by arteries where second exchange of gases occurs between blood and body cells. Blood gives oxygen to the body cells and takes carbon dioxide. Inside the cells,
oxygen is utilised for oxidation of simple nutrients to produce energy, carbon dioxide and water. Body cells give carbon dioxide to blood and deoxygenated blood is pumped to right atrium of heart from where pulmonary artery carries deoxygenated blood to lungs

Question: (a) Draw a sectional view of the human heart and label in it, aorta, right ventricle and pulmonary veins.(b) State the functions of the following components of transport system.
(i) Blood (ii) Lymph

Answer: (a) The sectional view of human heart is as follows: 

Life Processes Class 10 Science Exam Questions

(b) (i) Blood is a mobile connective tissue composed of a fluid, plasma and blood corpuscles.
Functions of blood are as follows:
— Blood takes part in transportation of respiratory gases (carbon dioxide and oxygen), nutrients and waste material in the body.
— White blood cells help to ght infection and protect from various pathogenic diseases.
— Lymphocytes of blood produce antibodies and provide immunity against various diseases
— When an injury is caused, the blood platelets release certain chemicals which help in
clotting of blood.
— Blood plasma helps in maintenance of blood pH and uniform distribution of heat in the body.
— Blood carries hormones from endocrine glands to the target organs.
(ii) Lymph is a mobile connective tissue comprising of lymph plasma (fluid) and lymph corpuscles (cells).
— Lymph acts as ‘middle man’, takes part in nutritive process of body. It transport protein molecules from tissue into blood stream.
— Body cells are kept moist by lymph.
— It absorbs and transports fat and fat soluble vitamins from intestine.
— Lymph drains excess fluid from extra cellular spaces back into blood.

Question: Draw a neat and labelled diagram of human excretory system. Describe in brief the function of kidneys, ureters, urinary bladder and urethra. 

Answer: The labelled diagram of human excretory system is as follows: 

Life Processes Class 10 Science Exam Questions

Functions :
(i) Kidneys : These are main or primary excretory organs present as one pair of large-sized, reddishbrown coloured and bean shaped structure in the upper part of abdomen. The function of kidneys is to remove the poisonous substance, urea, other waste salts and excess water from the blood and excrete them in the form of a yellowish liquid called urine.
(ii) Ureters : These are a pair of long, narrow, thinwalled and tubular structures which conduct the urine from the kidneys to urinary bladder.
(iii) Urinary bladder : It is a thin-walled, elastic, pear-shaped and distensible sac which temporarily stores the urine. Its wall is lined with smooth (involuntary) muscles.
(iv) Urethra : It is a muscular and tubular structure which carries the urine from urinary bladder to the outside.

Question: (a) Draw a schematic representation of transport and exchange of oxygen and carbon dioxide during transportation of blood in human beings and label on it: lung capillaries, pulmonary artery to lungs, aorta to body, pulmonary veins from lungs.
(b) What is the advantage of separate channels in mammals and birds for oxygenated and deoxygenated blood?

Answer: (a) The schematic representation of transport and exchange of oxygen and carbon dioxide is as follows:

Life Processes Class 10 Science Exam Questions

(b) In mammals and birds the two circulatory system (oxygenated blood and deoxygenated blood) become fully separate sending low pressure pumping to lungs and high pressure Low of blood to rest of body.This prevents any mixing of oxygenated and deoxygenated blood ensuring maximum supply of oxygen to all body parts.This allows optimum oxidation of glucose to release energy required by these animal groups to maintain their body temperature making them homeothermic.

Question: (a) Draw the structure of a nephron and label the following on it: glomerulus, Bowman’s capsule, renal artery, collecting duct.
(b) What happens to glucose that enters the nephron along with filtrate?

Answer: (a) The structure of a nephron is as follows: 

Life Processes Class 10 Science Exam Questions

(b) Glomerular filtrate present in Bowman’s capsule contains glucose.This filtrate when enters proximal convoluted tubule of kidney then, much of it is reabsorbed back here (65%). Glucose is almost completely reabsorbed in the kidney tubule and is not excreted out.

Question: (a) Draw a diagram of excretory system in human beings and label on it : aorta, vena cava, urinary bladder and urethra.
(b) List two vital functions of the kidney. 

Answer: (a)

Life Processes Class 10 Science Exam Questions

(b) Two vital functions of kidneys are:
(i) The most important function of kidneys is filtration of blood to excrete the waste products of metabolism. If these waste products, mainly nitrogenous waste such as urea and uric acid, are not removed from the blood, they will start accumulating to unbearable toxic levels.
(ii) Osmoregulation : Kidneys maintain water balance in the body and removes excess water.
Besides filtering out the waste products, the kidneys perform other functions such as secretion of erythropoietin, enzyme-renin, homeostasis and conversion of inactive form of vitamin D to the active form.

Life Processes Class 10 Science Exam Questions

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