Class 10 Science Chapter 6 Life Processes

Class 10 Science Chapter 6 Life Processes answer to each chapter is provided in the list so that you can easily browse throughout different chapters NCERT Class 10 Science Chapter 6 Life Processes and select need one.

Class 10 Science Chapter 6 Life Processes

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Also, you can read the SCERT book online in these sections Solutions by Expert Teachers as per SCERT (CBSE) Book guidelines. These solutions are part of SCERT All Subject Solutions. Here we have given Assam Board Class 10 Science Chapter 6 Life Processes Solutions for All Subjects, You can practice these here.

Life Processes

Chapter – 6


Textual Questions and Answers:

Q.1. Why is diffusion insufficient to meet the oxygen requirements of multicellular organisms like humans? 

Ans: Diffusion is insufficient to meet the oxygen requirement of multicellular organisms like human because all the cells are not direct contact in environment and diffusion is a slow process. Diffusion is too slow to cover the distance between the gas exchange surface and the sites where the oxygen is required.

Q.2. What criteria do we use to decide whether something is alive? 

Ans: Any visible movement such as walking, breathing, or growing is generally used to decide whether something is alive or not. However, a living organism can also have movements, which are not visible to the naked eye. Therefore, the presence of life processes is a fundamental criterion that can be used to decide whether something is alive or not.

Q.3. What are out side raw materials used by living organisms. 

Ans: The outside raw materials used by living organisms are: 

(i) Food.

(ii) Oxygen.

(iii) Water. 

Q.4. What processes would you consider essential for maintaining life. 

Ans: Life processes such as respiration, digestion, excretion, circulation and transportation are essential for maintain life.

Page – 101 

Q.1. What are the differences between autotrophic and heterotrophic nutrition? 

Ans: Autotrophic nutrition: In this type of nutrition, It occurs in green plants and blue green algae Co₂ organic compound. They need chlorophyll and sunlights.

Heterotrophic nutrition: In this type of nutrition, It occurs in animals and insectivorous plants. They depend on plants and herbivores for their food. There is no need of chlorophyll and sunlight. 

Q.2. Where do the plants get each of the raw materials required for photosynthesis? 

Ans: Required materials for photosynthesis are: 

(i) Carbon – dioxide: Which plants get from atmosphere. 

(ii) Water: Which plants get from soil. 

(iii) Sunlight: Which plants get from sun. 

(iv) Chlorophyll: It is present in green leaves plant. 

Q.3. What is the role of acid in our stomach? 

Ans: In the stomach, HCl dissolves food particles and produces an acidic environment. Pepsinogen is transformed to pepsin in an acidic environment by protein digesting enzymes. In addition, HCl works as a protective barrier in the stomach against a variety of disease-causing bacteria. 

Q.4. What is the function of digestive enzymes? 

Ans: Digestive enzymes such as amylase, lipase, pepsin, trypsin, etc., help in the chemical digestion of food by breaking down complex food particles into simpler ones. These simple molecules can be easily absorbed by the blood and is thus transported to all the cells in the body.

Q.5. How is the small intestine designed to absorb digested food? 

Ans: Small intestine is the longest part of the alimentary canal which is fitted into a compact space because of extensive coiling. 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 the repair of old tissues. 

Page – 105 

Q.1. What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration? 

Ans: Animals living in water need use the oxygen dissolved in water. However, the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air.

Hence, the aquatic organisms has much faster rate of breathing.

Terrestrial organisms, on the other hand, obtain oxygen from the oxygen – rich atmosphere through respiratory organs.

So, they breathe at a lesser rate than aquatic organisms.

Thus, terrestrial organisms can facilitate better utilization of food by way of respiration.

Q.2. What are the different ways in which glucose is oxidised to provide energy in various organisms? 

Ans: Different pathways to provide energy from glucose: 

Q.3. How is oxygen and carbon dioxide transported in human beings? 

Ans: Oxygen and Carbon-di-oxide is transported in human being via blood stream. Oxygen is carried to the cells whereas carbon-di-oxide is carried away from the cells. Exchange of gases takes place between the alveoli of lungs and the surrounding blood capillaries.  Oxygen is absorbed by the blood capillaries from the lungs alveoli by diffusion while carbon-dioxide is absorbed by the lungs alveoli from blood capillaries by diffusion.

Carbon dioxide is more soluble in water. Hence is mostly transported from body tissues in the dissolved form in our blood plasma to lung where it diffused from blood to air in the lungs. 

Q.4. How are the lungs designed in human beings to maximise the area for exchange of gases? 

Ans: The lungs contain alveoli which provide a surface where the exchange of gases can take place. The walls of the alveoli contain an extensive network of blood vessels. These alveoli increase surface area for exchange of gases. There are 750 million alveoli in the lungs of man. If the alveolar surface is spread out it would cover about 80m². Thus it makes efficient exchange of gases. 

Page – 110 

Q.1. What are the component of transport system in human tan beings? What are function of these components? 

Ans: The components of the transport system in human beings are the heart, blood, and blood vessels. 

Functions of the components: 

(i) Heart: Heart is a pumping organ to push blood around the body. It receives deoxygenated blood from the body parts and pump it to lungs for enriching with oxygen. It receives purified blood from lungs and pumps it around the body. 

(ii) Blood: Blood is fluid connective tissue. It consists of plasma in which the cells are suspended, such as WBC and RBC. Plasma transports food, carbon dioxide and nitrogenous wastes in dissolved form. RBC transports oxygen. Blood also transport many other substances like hormones, salt etc. Platelets present in the blood stop bleed from injuries by forming blood clots. 

(iii) Blood vessels: The blood vessels which carry oxygenated blood are called arteries. They divide to form capillaries of finer dimensions. Exchange of materials takes place across the capillaries. It is possible because the wall of capillaries are extremely thin. The blood from the tissues is returned by veins.

Q.2. Why it is necessary to separate the oxygenated and deoxygenated blood in mammals and birds? 

Ans: Separation of oxygenated and deoxygenated blood allows a highly efficient supply of oxygen to the body. Such separation allows a highly efficient supply of oxygen to the body. This is useful in animals that have high energy needs, such as birds and mammals, which constantly use energy to maintain their body temperature.

Q.3. What are the components of the transport system in highly organised plants? 

Ans: The component of the transport system in highly organised plants are: 

(i) Xylem.

(ii) Phloem. 

Q.4. How are water and minerals transported in plants? 

Ans: Water and Minerals are transported in plants by the Xylem:

  • The roots of a plant have hair called root hairs.
  • These root hairs absorb water and minerals from soil since these are directly in contact with the film of water in between the soil particles.
  • Water gets into the root hair by the process of diffusion.
  • These minerals and water absorbed by root hair pass from cell to cell by osmosis through the epidermis, root cortex, endodermis and reach the root xylem.
  • The pressure at the top of the xylem vessels is lowered whereas the pressure at the bottom of the xylem vessels remains high.
  • Due to this, the water flows up the xylem vessels into the leaves, where it leaves by transpiration.

Q.5. How is food transported in plants? 

Ans: Phloem transports food materials from the leaves to different parts of the plant. The transportation of food in phloem is achieved by utilizing energy from ATP which helps in creating osmotic pressure that transports food from the area of high concentration to low concentration. This movement of food materials is carried out in phloem by sieve tabes with the help of companion cells. 

Page – 112 

Q.1. Describe the structure and functioning of nephron. 

Ans: Structure of Nephron: A nephron is made up of a globular double walled. Bowman’s capsule around a clump of capillaries of glomerulus and a tubule surrounded by blood capillaries. The tabule consists of a proximal convoluted portion, the loop of Henle, with descending and ascending limbs and a distal convoluted part.

Function of nephron: 

(i) Filtration of blood takes place in Bowman’s capsule from the capillaries of glomerules. The filtrate passes into the tabular part of the nephron. This filtrate contains glucose, amino acids, urea, uric acid, salts and a major amount of water. 

(ii) As the filtrate flows along the tabule, useful substances such as glucose, amino acids, salts and water are seleebvely reabsorbed into the blood by capillaries surrounding the nephron tubule. 

(iii) The filtrate which remained after reabsorption is called urine, urine contains dissolved nitrogenous waste i.e. urea and uric acid, excess salts and water. Urine is collected from nephrons by the collecting dust to carry it to the ureter. 

Q.2. What are the methods used by plants to get rid of excretory products? 

Ans: Plants can get rid of excess water by transpiration. For other wastes, plants use the fact that many of their tissues consist of dead cells and that they can even lose parts such as leaves. Many plant waste products are stored in cellular vacuoles. Waste products may be stored in leaves that fall off. Other waste products are stored as resins and gums, especially in old xylem. Plants also excrete some waste substances into the soil around them. 

Q.3. How is the amount of urine produced regulated? 

Ans: (i) Amount of urine formed depends upon how much excess water there is in the body. 

(ii) When there is more quantity of dissolved wastes in the body, more quantity of water is required to excrete them. So the amount of urine produced increases. 

(iii) The amount of urine produced is also regulated by certain hormones which control the movement of water and Na ions and out of he nephrons. 

Select the Correct Answers: 

Page – 133 

Q.1. The kidneys in human being are a part of the system for 

(a) Nutrition.

(b) Respiration.

(c) Excretion.

(d) Transportation. 

Ans: (c) Excretion. 

Q.2. The xylem in plants are responsible for – 

(a) Transport of water.

(b) Transport of food.

(c) Transport of amino acids.

(d) Transport of oxygen.

Ans: (a) Transport of water. 

Q.3. The autotrophic mode of nutrition requires : 

(a) Co₂ and water.

(b) Chlorophyll.

(c) Sunlight.

(d) All of above.

Ans: (d) All of above. 

Q.4. The breakdown of pyruvate to give Co₂, water and energy takes place in: 

(a) Cytoplasm.

(b) Mitochondria.

(c) Chloroplast.

(d) Nucleus.

Ans: (b) Mitochondria. 

Textual Questions and Answers:

Q.1. How ae fats digested in our bodies? Where does the process take place? 

Ans: Fats are present in the form of large globules in the small intestine. The small intestine receives the secretions from the liver and the pancreas. The pancreas secretes pancreatic juice which contains enzymes like trypsin for digesting proteins and lipase for breaking down emulsified fats. 

The walls of the small intestine contain glands which secrete intestinal juice. The enzymes present in it finally convert the fats into fatty acids and glycerol. Digestion of fat takes place in the small intestine.

Q.2. What is the role of saliva in the digestion of food? 

Ans: Saliva contains a digestive enzyme called salivary amylase, which breaks down starch into sugar. The food is mined thoroughly with saliva and moved around the mouth which chewing by the muscular tongue.

Q.3. What are the necessary conditions for autotrophic nutrition and what are its by – products? 

Ans: Necessary conditions for autotrophic nutrition: 

(i) Presence of chlorophyll in the living cells. 

(ii) Co₂ is necessary.

(iii) Sunlight is necessary. 

(iv) Water is required. 

By – products: Molecular oxygen is liberated as a byproduct. 

Q.4. What are the differences between aerobic and an but aerobic respiration? Name some organisms that use the anaerobic mode of respiration. 


Aerobic respirationAnaerobic respiration
It takes place in the presence of oxygen.It takes place in the absence of oxygen.
Complete oxidation of glucose takes place.Glucose molecule is incompletely broken down.
Large amount of energy is released.Small amount of energy is released.

An aerobic respiration take place in bacteria, yeast and Muscle cells. 

Q.5. How are the alveoli designed to maximise the exchange of gases?

Ans: Alveoli are pouch-like air sac that is made up of simple squamous epithelium. It has a thin cell wall to facilitate gaseous exchange. 

The presence of millions of alveoli in the lungs provides ample surface area to facilitate gaseous exchange between the air in alveoli and blood in surrounding capillaries. 

Oxygen diffuses across the alveolar and capillary wall into the bloodstream while carbon dioxide diffuses from blood across the mentioned walls into the alveoli.

Q.6. What would be consequences of a deficiency of haemoglobin in our bodies? 

Ans: Consequences of a deficiency of hemoglobin:

1. Hemoglobin is a pigment that is helpful in supplying oxygen in all the parts of the body through blood.

2. It is present in the red blood cells and acts as a carrier of oxygen.

3. The deficiency of hemoglobin makes an individual anemic which means fewer red blood cells.

4. The deficiency of hemoglobin will decrease the oxygen-carrying capacity of the blood.

5. A decrease in hemoglobin in blood will lead to slow functioning of body parts and weakness due to the less supply of oxygen.

Q.7. Describe double circulation in human beings . Why is it necessary? 

Ans: Double circulation: In human beings the blood goes through the heart twice during each cycle. i.e., the blood passes through the human heart two times to supply once to the whole body. So, it is called the double circulation of blood. 

The double circulation of blood includes: 

(i) Systemic circulation. and

(ii) Pulmonary circulation.

(i) Systemic circulation: It supplies oxygenated blood from left auricle to left ventricle there by pumped to various body parts. The deoxygenated blood is collected from the various body organs by the veins to pour into vena cava and finally into right atrium. Right atrium transfers the blood in to the right ventricle. 

(ii) Pulmonary circulation: The deoxygenated blood is pushed by the right ventricle into the lungs for oxygenation. The oxygenated blood is brought back to left atrium of the human heart. From left atrium the oxygenated blood is pushed into the left ventricle. The left ventricle pumps oxygenated blood into aosta for systemic circulation. 

(iii) Necessity of double circulation: The right side and the left side of the human heart is useful to keep deoxygenated and oxygenated blood from mining. This type of separation of oxygenated and deoxygenated blood ensures a highly efficient supply of oxygen to the body. This is useful in case of humans which constantly require energy to maintain their body temperature. 

Q.8. What are the differences between the transport of materials in xylem and phloem? 

Ans: Xylem is a conducting tissue that is responsible for the transport of water while phloem is a conducting tissue that is responsible for the transport of food in plants.

Difference between xylem and phloem:

Water is absorbed by the roots and is transported to the aerial parts of the plant like the stem and leaves.Food is formed in the leaves from where it is transported to the storage organs and the growing parts of the plants.
In xylem, upward, movement of water and dissolved minerals transferred into phloem tissue is mainly achieved by transpiration pull. It is caused due to suction, created by evaporation of water molecules from the cells of leaves.In translocation, material is transferred in the phloem tissue emerge from ATP. This increase the osmotic Pressures that movies the material in the phloem to tissue which have less pres pressure.

Q.9. Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning. 

Ans: Part of the renal cortex, a medullary ray is a collection of renal tubules that drain into a single collecting duct.

The comparison of Alveoli in the lungs and Nephrons in the kidneys are as follows:

Alveoli have thin walled balloon like structure . Scarface is fine and delicate.Nephron have thin walled cup shaped structure attached with thin walled tubule.
Alveoli only provide surface for exchange of gases in the lungs.Tubular part of nephron also carries the urine to collecting duct.

Multiple Choice Questions:

Q.1. Which is end product of glycolysis?  

(a) Pyruvic acid.

(b) Acetyl Co A. 

(c) Lactic acid.

(d) Citric acid.

Ans: (a) Pyruvic acid.

Q.2. Functional unit in kidney is – 

(a) Nephron.

(b) Nephritis.

(c) Neuron.

(d) Loop of Henle. 

Ans: (a) Nephron.  

Q.3. The conversion of proteins waste, the ammonia into urea occurs mainly is 

(a) Liver.

(b) kidney. 

(c) Lungs.

(d) Intestine.

Ans: (a) Liver.

Q.4. The green colour of plants is due to the presence of 

(a) Chlorophyll.

(b) Carotene.

(c) Xanthophyll.

(d) Starch.

Ans: (a) Chlorophyll.  

Q.5. Saliva contains: 

(a) Renvin.

(b) Pepsin.

(c) Ptyalin.

(d) Trypsin.

Ans: (c) Ptyalin.

Q.6. The first step of break down of glucose takes place in 

(a) Nucleus.

(b) Mitochondria.

(c) Cytoplasm.

(d) Lysosomes.

Ans: (c) Cytoplasm.  

Q.7. Water absorption by roots is under the influence of 

(a) Evaporation pull.

(b) Transpiration pull.

(c) Soil air.

(d) Availability of soil water.

Ans: (d) Availability of soil water.

Q.8. The chemical process that causes digestion of food by enzymes is called

(a) Dehydration.

(b) Hydration.

(c) Hydrolyses.

(d) Oxidations.

Ans: (c) Hydrolyses. 

Q.9. Major function of Hcl of gastric juice is 

(a) Providing acidic medium for pepsin.

(b) Facilitates absorption of food.

(c) kills microorganisms.

(d) (a) and (c) 

Ans: (d) (a) and (c) 

Q.10. Urea formation takes place in 

(a) Liver.

(b) kidney.

(c) Lungs.

(d) Skin.

Ans: (a) Liver.

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