---
title: "NCERT Solutions for Class 10 Science Chapter 5 Life Processes"
url: https://www.swavid.com/science/class/10/chapter/life-processes/ncert-solutions
dateModified: 2026-10-07T16:45:13+00:00
---

# NCERT Solutions for Class 10 Science Chapter 5 Life Processes

This chapter's questions cover fundamental biological concepts related to life processes such as nutrition, respiration, transportation, and excretion in both plants and animals. They test students' understanding of physiological systems, biochemical pathways, and structural adaptations.

Free PDF (14 pages): https://www.swavid.com/api/seo/pdf/ncert/science/class-10/swavid-ncert-solutions-class-10-science-chapter-5-life-processes-5e1518f05e.pdf

## QUESTIONS

### Question 1

*3 marks · Short answer*

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

**Solution**

1. In multi-cellular organisms like humans, all the cells are not in direct contact with the surrounding environment.
2. Therefore, simple diffusion cannot meet the oxygen requirements of all the cells.
3. Instead, specialised systems like the respiratory and circulatory systems are needed to transport oxygen to all parts of the body.

**Answer:** Diffusion is insufficient because multi-cellular organisms have complex body designs where most cells are not in direct contact with the environment.

> Common mistake: Writing that diffusion is slow without mentioning cell contact with the environment.

### Question 2

*2 marks · Very short answer*

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

**Solution**

1. We use movements over very small scales, such as invisible molecular movements, as the primary criteria to decide whether something is alive.

**Answer:** Molecular movement is the main criterion used to decide whether something is alive.

> Common mistake: Stating visible movement or breathing, which are not universal for all living beings like plants.

### Question 3

*2 marks · Very short answer*

What are outside raw materials used for by an organism?

**Solution**

1. Outside raw materials, primarily in the form of food and oxygen, are used by organisms as a source of energy and for growth, development, and synthesis of substances needed in the body.

**Answer:** Outside raw materials are used to provide energy and for body growth and maintenance.

> Common mistake: Forgetting to mention energy alongside raw materials for growth.

### Question 4

*2 marks · Very short answer*

What processes would you consider essential for maintaining life?

**Solution**

1. The processes essential for maintaining life are nutrition, respiration, transportation of materials within the body, and excretion of waste products.

**Answer:** Nutrition, respiration, transportation, and excretion are considered essential life processes.

> Common mistake: Omitting one of the four main life processes mentioned in the chapter.

## QUESTIONS

### Question 1

*3 marks · Short answer*

What are the differences between autotrophic nutrition and heterotrophic nutrition?

**Solution**

1. In autotrophic nutrition, organisms prepare their own food from simple inorganic substances like carbon dioxide and water using sunlight and chlorophyll, whereas in heterotrophic nutrition, organisms take in complex substances prepared by other organisms.
2. Autotrophs include green plants and some bacteria, while heterotrophs include animals and fungi.
3. Autotrophic organisms contain chlorophyll to trap sunlight, whereas heterotrophic organisms lack chlorophyll and depend directly or indirectly on autotrophs for food.

**Answer:** Autotrophic nutrition involves synthesizing food from inorganic raw materials, while heterotrophic nutrition involves depending on complex food prepared by other organisms.

> Common mistake: Confusing the examples of autotrophs and heterotrophs or forgetting to mention the role of sunlight and chlorophyll.

### Question 2

*3 marks · Short answer*

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

**Solution**

1. Carbon dioxide is taken up from the atmosphere by plants through stomata present on the surface of leaves.
2. Water used in photosynthesis is taken up from the soil by the roots of terrestrial plants through absorption.
3. Other materials like nitrogen, phosphorus, iron, and magnesium are also absorbed from the soil by the roots in the form of inorganic salts or compounds.

**Answer:** Plants obtain carbon dioxide from the atmosphere, and water along with minerals from the soil through their roots.

> Common mistake: Stating that water is absorbed from the air or forgetting minerals absorbed from the soil.

### Question 3

*2 marks · Very short answer*

What is the role of the acid in our stomach?

**Solution**

1. The hydrochloric acid secreted by the gastric glands creates an acidic medium which facilitates the action of the protein-digesting enzyme pepsin.
2. It also kills harmful bacteria that may enter along with the food.

**Answer:** Hydrochloric acid creates an acidic medium for pepsin action and kills bacteria in the stomach.

> Common mistake: Omitting the activation of pepsin or mentioning digestion of food directly by the acid.

### Question 4

*2 marks · Very short answer*

What is the function of digestive enzymes?

**Solution**

1. Digestive enzymes act as biological catalysts to break down complex food substances into smaller, simpler molecules.
2. These simpler molecules can be easily absorbed across the walls of the alimentary canal into the body.

**Answer:** Digestive enzymes break down complex food molecules into simpler forms so that they can be easily absorbed by the body.

> Common mistake: Writing that enzymes digest food without explaining the conversion of complex molecules into simpler ones.

### Question 5

*3 marks · Short answer*

How is the small intestine designed to absorb digested food?

**Solution**

1. The small intestine is very long and extensively coiled to increase the time and area for food absorption.
2. The inner lining of the small intestine has numerous finger-like projections called villi which greatly increase the surface area for absorption.
3. The villi are richly supplied with blood vessels that take the absorbed food to each and every cell of the body.

**Answer:** The small intestine is adapted through extensive coiling, presence of finger-like villi to increase surface area, and a rich supply of blood vessels.

> Common mistake: Forgetting to mention the role of blood vessels or villi in absorbing and transporting digested food.

## QUESTIONS

### Question 1

*3 marks · Short answer*

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

**Solution**

1. Terrestrial organisms take up oxygen from the atmosphere, whereas aquatic organisms obtain oxygen dissolved in water.
2. Since the amount of dissolved oxygen is fairly low compared to the amount of oxygen in the air, the rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms.
3. Therefore, terrestrial organisms have the advantage of getting more oxygen with a much less rapid breathing rate.

**Answer:** Terrestrial organisms breathe atmospheric oxygen which has a much higher concentration than dissolved oxygen, allowing them to have a slower breathing rate compared to aquatic organisms.

> Common mistake: Confusing the concentration of oxygen in air and water, or missing the comparison of breathing rates.

### Question 2

*3 marks · Short answer*

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

**Solution**

1. In all organisms, the first step is the breakdown of glucose, a six-carbon molecule, into a three-carbon molecule called pyruvate in the cytoplasm.
2. In anaerobic respiration (such as in yeast during fermentation), pyruvate is converted into ethanol and carbon dioxide in the absence of oxygen.
3. In lack of oxygen (such as in human muscle cells during sudden activity), pyruvate is converted into lactic acid, causing cramps, while in the presence of oxygen (aerobic respiration in mitochondria), pyruvate is broken down to give carbon dioxide, water, and a large amount of energy.

**Answer:** Glucose is first broken down into pyruvate in the cytoplasm, which is then oxidised either anaerobically into ethanol or lactic acid, or aerobically into carbon dioxide and water in the mitochondria.

> Common mistake: Forgetting that the first step of breaking glucose into pyruvate happens in the cytoplasm for all pathways.

### Question 3

*3 marks · Short answer*

How is oxygen and carbon dioxide transported in human beings?

**Solution**

1. Oxygen is carried by the respiratory pigment haemoglobin present in the red blood corpuscles from the lungs to the tissues.
2. Carbon dioxide is more soluble in water than oxygen is and hence is mostly transported in the dissolved form in our blood.

**Answer:** Oxygen is transported by haemoglobin in red blood corpuscles, while carbon dioxide is mostly transported in dissolved form in blood.

> Common mistake: Students often forget that carbon dioxide is mostly carried in dissolved form in plasma rather than by haemoglobin.

### Question 4

*3 marks · Short answer*

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

**Solution**

1. Within the lungs, the passage divides into smaller and smaller tubes which finally terminate in balloon-like structures called alveoli.
2. The alveoli provide a very large surface area where the exchange of gases can take place.
3. The walls of the alveoli contain an extensive network of blood-vessels to facilitate efficient gas exchange.

**Answer:** Lungs maximise the exchange area through millions of balloon-like structures called alveoli, which are richly supplied with blood vessels.

> Common mistake: Not mentioning alveoli or the extensive network of blood vessels.

## QUESTIONS

### Question 1

*3 marks · Short answer*

What are the components of the transport system in human beings? What are the functions of these components?

**Solution**

1. The components of the human transport system are the heart, blood, and blood vessels.
2. The heart acts as a pumping organ to push blood around the body.
3. Blood transports food, oxygen, and waste materials, while blood vessels (arteries, veins, and capillaries) form a network of tubes to reach all tissues.

**Answer:** The components are the heart, blood, and blood vessels, which together pump blood and transport oxygen, nutrients, and wastes across the body.

> Common mistake: Forgetting to mention the functions of individual components like blood vessels and the heart.

### Question 2

*3 marks · Short answer*

Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?

**Solution**

1. Mammals and birds have high energy needs because they constantly use energy to maintain their body temperature.
2. Separation of the right and left sides of the heart prevents oxygen-rich blood from mixing with blood containing carbon dioxide.
3. This ensures a highly efficient supply of oxygen to the body to meet their constant energy requirements.

**Answer:** It is necessary to provide a highly efficient supply of oxygen to meet the high energy needs of warm-blooded animals that maintain their body temperature.

> Common mistake: Omitting the link between body temperature maintenance and high energy needs.

### Question 3

*2 marks · Very short answer*

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

**Solution**

1. The transport system in highly organised plants consists of vascular tissues.
2. These are xylem, which transports water and minerals, and phloem, which transports products of photosynthesis.

**Answer:** Xylem and phloem are the two components of the transport system in highly organised plants.

> Common mistake: Naming only xylem and forgetting phloem.

### Question 4

*3 marks · Short answer*

How are water and minerals transported in plants?

**Solution**

1. Water and minerals are transported through the xylem tissue consisting of vessels and tracheids in roots, stems, and leaves.
2. At the roots, cells actively take up ions, creating a concentration difference that causes water to move into the root xylem and create root pressure.
3. During the day, transpiration creates a suction pull (transpiration pull) that is the major driving force drawing water upwards through the xylem.

**Answer:** Water and minerals are transported upwards through the xylem via root pressure and primarily transpiration pull.

> Common mistake: Stating that root pressure is the main force responsible for water movement in tall trees during the day.

### Question 5

*3 marks · Short answer*

How is food transported in plants?

**Solution**

1. Food and other substances are transported in plants through the phloem tissue, specifically via sieve tubes with the help of adjacent companion cells.
2. This transport, called translocation, occurs in both upward and downward directions using energy from ATP.
3. Material like sucrose is transferred into phloem tissue using ATP, increasing osmotic pressure and causing water to move in, which pushes the material to tissues with less pressure according to the plant's needs.

**Answer:** Food is transported through the phloem in both upward and downward directions by utilizing energy from ATP, which creates an osmotic pressure gradient.

> Common mistake: Stating that food transport in phloem relies solely on physical forces like transpiration pull.

## QUESTIONS

### Question 1

*3 marks · Short answer*

Describe the structure and functioning of nephrons.

**Solution**

1. Each nephron consists of a cup-shaped Bowman's capsule associated with a cluster of very thin-walled blood capillaries called glomerulus.
2. The Bowman's capsule collects the initial filtrate produced from blood under pressure.
3. As the filtrate flows along the tubular part of the nephron, useful substances like glucose, amino acids, salts and a major amount of water are selectively re-absorbed, while nitrogenous wastes form urine which is collected and passed to the ureter.

**Answer:** Nephrons filter nitrogenous wastes through Bowman's capsule and selectively re-absorb useful substances along the tubule to form urine.

> Common mistake: Forgetting to mention selective re-absorption of water and useful substances along the tubular part.

### Question 2

*3 marks · Short answer*

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

**Solution**

1. Plants can get rid of excess water by transpiration and can consider oxygen as a waste product generated during photosynthesis.
2. Many plant waste products are stored in cellular vacuoles or in leaves that fall off.
3. Other waste products such as resins and gums are stored in old xylem, and some waste substances are excreted into the soil around them.

**Answer:** Plants use methods like transpiration, storing wastes in vacuoles or falling leaves, storing gums and resins in old xylem, and excreting into the soil.

> Common mistake: Writing animal excretion methods instead of plant-specific mechanisms.

### Question 3

*2 marks · Very short answer*

How is the amount of urine produced regulated?

**Solution**

1. The amount of urine produced depends on the amount of excess water present in the body and on how much of dissolved waste there is to be excreted.
2. The quantity of water re-absorbed along the tubular part of the nephron regulates the final volume of urine produced.

**Answer:** The amount of urine produced is regulated by the amount of excess water and dissolved wastes in the body and the re-absorption of water along the nephron tubule.

> Common mistake: Stating that urine amount depends only on water intake without mentioning dissolved wastes and tubular re-absorption.

## EXERCISES

### Question 1

*1 mark · MCQ*

The kidneys in human beings are a part of the system for

- nutrition.
- respiration.
- excretion.
- transportation.

**Solution**

1. The kidneys filter nitrogenous wastes from the blood to form urine.
2. Thus, they are a part of the human excretory system, corresponding to option (c).

**Answer:** (c) excretion.

> Common mistake: Confusing kidneys with circulatory organs due to their rich blood supply.

### Question 2

*1 mark · MCQ*

The xylem in plants are responsible for

- transport of water.
- transport of food.
- transport of amino acids.
- transport of oxygen.

**Solution**

1. Xylem is the vascular tissue in plants responsible for the transport of water and minerals obtained from the soil.
2. Thus, the correct option is (a).

**Answer:** (a) transport of water.

> Common mistake: Confusing xylem with phloem, which transports food.

### Question 3

*1 mark · MCQ*

The autotrophic mode of nutrition requires

- carbon dioxide and water.
- chlorophyll.
- sunlight.
- all of the above.

**Solution**

1. Autotrophic nutrition requires carbon dioxide and water, chlorophyll, and sunlight to carry out photosynthesis.
2. Therefore, all the given conditions are necessary, making option (d) the correct choice.

**Answer:** (d) all of the above.

> Common mistake: Selecting only carbon dioxide and water while ignoring sunlight or chlorophyll.

### Question 4

*1 mark · MCQ*

The breakdown of pyruvate to give carbon dioxide, water and energy takes place in

- cytoplasm.
- mitochondria.
- chloroplast.
- nucleus.

**Solution**

1. The breakdown of pyruvate using oxygen to give carbon dioxide, water and energy takes place in the mitochondria.
2. Thus, the correct option is (b).

**Answer:** (b) mitochondria.

> Common mistake: Confusing the site of glucose breakdown into pyruvate (cytoplasm) with complete breakdown of pyruvate (mitochondria).

### Question 5

*3 marks · Short answer*

How are fats digested in our bodies? Where does this process take place?

**Solution**

1. Fats are present in the intestine in the form of large globules which make it difficult for enzymes to act on them.
2. Bile salts secreted by the liver break down these large fat globules into smaller globules, increasing enzyme efficiency through emulsification.
3. The pancreas secretes pancreatic juice containing the enzyme lipase, which breaks down emulsified fats into fatty acids and glycerol in the small intestine.

**Answer:** Fats are emulsified by bile salts and subsequently broken down by lipase into fatty acids and glycerol in the small intestine.

> Common mistake: Omitting the role of bile in emulsifying fats before enzymatic action.

### Question 6

*2 marks · Very short answer*

What is the role of saliva in the digestion of food?

**Solution**

1. Saliva wets the food to make passage through the alimentary canal smooth and contains the enzyme salivary amylase.
2. Salivary amylase breaks down complex starch into simple sugar.

**Answer:** Saliva moistens food for smooth passage and contains salivary amylase, which digests complex starch into simple sugar.

> Common mistake: Forgetting that saliva contains an enzyme and only describing it as water.

### Question 7

*3 marks · Short answer*

What are the necessary conditions for autotrophic nutrition and what are its by-products?

**Solution**

1. The necessary conditions for autotrophic nutrition are the presence of sunlight, chlorophyll, carbon dioxide, and water.
2. Carbon dioxide and water are taken in from the outside and converted into carbohydrates in the presence of sunlight and chlorophyll.
3. The by-products of photosynthesis are oxygen and water.

**Answer:** Necessary conditions are sunlight, chlorophyll, carbon dioxide, and water, while oxygen and water are the by-products.

> Common mistake: Forgetting to mention water as a by-product of photosynthesis.

### Question 8

*3 marks · Short answer*

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

**Solution**

1. Aerobic respiration takes place in the presence of oxygen, whereas anaerobic respiration takes place in the absence of oxygen.
2. Aerobic respiration yields a large amount of energy and produces carbon dioxide and water, while anaerobic respiration releases much less energy and produces products like ethanol and carbon dioxide or lactic acid.
3. Organisms such as yeast use the anaerobic mode of respiration.

**Answer:** Aerobic respiration uses oxygen and yields more energy, while anaerobic respiration occurs without oxygen; yeast is an example of an organism using anaerobic respiration.

> Common mistake: Confusing the end products of fermentation in yeast with those in muscle cells.

### Question 9

*3 marks · Short answer*

How are the alveoli designed to maximise the exchange of gases?

**Solution**

1. Within the lungs, the passage divides into smaller tubes that terminate in balloon-like structures called alveoli.
2. The alveoli provide a very large surface area where the exchange of gases can take place.
3. The walls of the alveoli contain an extensive network of blood-vessels to facilitate efficient gas exchange.

**Answer:** Alveoli provide a balloon-like structure with a vast surface area and a dense network of blood vessels to maximise gas exchange.

> Common mistake: Omitting the presence of the extensive network of blood vessels surrounding the alveolar walls.

### Question 10

*3 marks · Short answer*

What would be the consequences of a deficiency of haemoglobin in our bodies?

**Solution**

1. Haemoglobin is the respiratory pigment present in red blood corpuscles that has a very high affinity for oxygen and carries it to body tissues.
2. A deficiency of haemoglobin leads to a reduced oxygen-carrying capacity of the blood.
3. This results in a deficiency of oxygen delivery to body cells, causing fatigue, weakness, and a condition known as anaemia.

**Answer:** Haemoglobin deficiency reduces oxygen transport in the blood, leading to anaemia, fatigue, and inefficient energy production in cells.

> Common mistake: Failing to connect lower oxygen transport directly to reduced energy release and symptoms like fatigue.

### Question 11

*3 marks · Short answer*

Describe double circulation of blood in human beings. Why is it necessary?

**Solution**

1. Double circulation means that the blood passes through the heart twice during each cycle of passage through the body.
2. Deoxygenated blood is pumped to the lungs for oxygenation, and the oxygenated blood returns to the heart before being pumped to the rest of the body.
3. This separation is necessary to prevent the mixing of oxygenated and deoxygenated blood, ensuring a highly efficient supply of oxygen to meet the high energy needs of warm-blooded animals like mammals and birds.

**Answer:** Double circulation involves blood passing through the heart twice per cycle, which is necessary to completely separate oxygenated and deoxygenated blood for an efficient oxygen supply.

> Common mistake: Not stating why the separation of blood streams is vital for animals with high energy needs.

### Question 12

*3 marks · Short answer*

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

**Solution**

1. Xylem transports water and minerals obtained from the soil, whereas phloem transports products of photosynthesis from the leaves to other parts of the plant.
2. Transport in xylem is largely achieved through simple physical forces such as root pressure and transpiration pull, moving upwards.
3. Transport in phloem (translocation) utilizes energy from ATP to move substances like sucrose in both upward and downward directions.

**Answer:** Xylem carries water and minerals upwards using physical forces, while phloem transports food in both directions using metabolic energy.

> Common mistake: Stating that phloem transport is unidirectional like xylem, ignoring the bidirectional movement of food.

### Question 13

*5 marks · Long answer*

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

**Solution**

1. Structure of Alveoli: Alveoli are tiny, balloon-like structures present inside the lungs that provide a very large surface area for the exchange of gases.
2. Functioning of Alveoli: The walls of alveoli are richly supplied with blood vessels where oxygen from inhaled air is taken up by blood and carbon dioxide from the blood is released into the alveolar air.
3. Structure of Nephrons: Nephrons are the basic filtration units of the kidneys, consisting of a cluster of very thin-walled blood capillaries called glomerulus associated with a cup-shaped Bowman's capsule and a long tubular part.
4. Functioning of Nephrons: Blood is filtered through the glomerulus into Bowman's capsule, where essential substances like glucose, amino acids, salts, and water are selectively re-absorbed as the filtrate flows along the tube, and nitrogenous wastes are removed as urine.
5. Comparison: Both are specialised structures with extensive networks of blood capillaries designed to maximise exchange and filtration across very thin walls, but alveoli exchange gases ($O_2$ and $CO_2$) with air, whereas nephrons filter nitrogenous wastes and excess water from the blood.

**Answer:** Alveoli in the lungs maximize gas exchange between air and blood, while nephrons in the kidneys filter nitrogenous wastes and regulate water and salt balance from the blood.

> Common mistake: Confusing the location and substances transported or filtered by alveoli versus nephrons.

## Frequently asked questions

### How many questions and exercises are there in the NCERT Solutions for Class 10 Science Chapter 5 Life Processes on SwaVid?

This chapter features 21 questions across internal sections and 13 exercise questions covering a wide range of topics. You can access SwaVid's free PDF and step-by-step solutions for all these questions on this page only.

### Which topics are covered in the internal questions of Class 10 Science Chapter 5?

The internal questions cover essential concepts such as the criteria for life, diffusion versus multicellular transport, autotrophic and heterotrophic nutrition, human and plant transport systems, and nephron functioning. SwaVid's free PDF and step-by-step solutions on this page only help you master all these topics.

### What concepts are included in the exercise questions of Class 10 Science Chapter 5 Life Processes?

The exercise questions include important concepts like aerobic and anaerobic respiration, autotrophic nutrition requirements, digestion of fats, and the comparison of alveoli and nephrons in structure and functioning. You can find SwaVid's free PDF and step-by-step solutions for these exercises on this page only.

### Which question type is considered the hardest in Class 10 Science Chapter 5 and how should I approach it?

Long answer questions involving detailed biological processes like cellular respiration pathways or the structure and functioning of nephrons are often found challenging by students. To score well, break down the process step-by-step and use neat diagrams, which are clearly explained in SwaVid's free PDF and step-by-step solutions available on this page only.

### How should I write answers to get full marks in Class 10 Science Chapter 5 examinations?

To secure full marks, structure your answers with precise scientific terms, bullet points for multi-part processes, and properly labelled diagrams wherever necessary. You can learn the ideal answer-writing format from SwaVid's free PDF and step-by-step solutions provided on this page only.

## Related pages

- [Life Processes: CBSE previous year questions](https://www.swavid.com/cbse/class-10/science/pyq/life-processes)
- [Class 10 Science chapters](https://www.swavid.com/science/class/10)

Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student