NCERT Solutions Class 10 for Science Chapter 6 Life Processes : In this post, we will share with you all the detailed NCERT Solutions of Class 10 Science Chapter 6 Life Processes. This will contain both in-text and back-exercise questions for Science and Social Science, and all exercise questions for Mathematics. For all school and board level examinations, doing all the NCERT Questions is a must.

Why are NCERT Questions Important?

NCERT Questions and Answers not only help you get hold of concepts firmly and enhance your understanding, but also form the base of all types of questions asked in exams. Questions asked in exam are more or less the same type as mentioned in NCERT. Moreover, sometimes the questions in NCERT are directly asked in exams, as it is, without any changes.

Hence, it’s very important to understand NCERT Questions and Answers.

In-Text Questions (Page 95)

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

Answer 1:|
In multicellular organisms like humans, all the body cells are not in direct contact with the surrounding environment. Therefore, every cell of the body will not get oxygen as per need by the process of diffusion from the environment. Therefore diffusion is insufficient to meet the oxygen requirements of multicellular organisms.

Question 2:
What criteria do we use to decide whether something is alive ?

Answer 2:
The main criteria used to decide whether something is alive are breathing and respiration. However, living beings also show growth and movement.

Question 3:
What are outside raw materials used by an organism ?

Answer 3:
Outside raw material is used by organism for food and oxygen. Raw materials requirement varies on the complexity of the organism and the environment it is living.

Question 4:
What processes would you consider essential for maintaining life?

Answer 4:
Life processes such as respiration, digestion, excretion, circulation and transportation are essential for maintain life.

In-Text Questions (Page 101)

Question 1:
What are the differences between autotrophic nutrition and heterotrophic nutrition?

Answer 1:












Question 2:
Where do plants get each of the raw materials required for photosynthesis?

Answer 2:
Plants required the following raw material for photosynthesis
CO2 is obtained from atmosphere through stomata
Water is absorbed by plant roots from the soil.
Sunlight is an essential raw material for photosynthesis
Nutrients are obtained by soil by plant roots

Question 3:
What is the role of the acid in our stomach?

Answer 3:
Role of acid in our stomach is :
(i) To make acidic medium which is necessary for the activation of the enzyme pepsin.
(ii) To kill bacteria which the food may contain.

Question 4:
What is the function of digestive enzymes ?

Answer 4:
The food we eat is complex in nature, i.e., it contains complex molecules. Digestive enzymes break down these complex molecules into smaller simpler molecules so that they can be absorbed by the walls of the intestine.

Question 5:
How is the small intestine designed to absorb digested food ?

Answer 5:
The small intestine is designed to provide maximum area for absorption of digested food and its transfer into the blood for its circulation into the body. For this the inner lining of the small intestine has numerous finger-like projections called villi. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body.

In-Text Questions (Page 105)

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

Answer 1:
Aquatic organisms use oxygen dissolved in surrounding water. Since air dissolved in water has fairly low concentration of oxygen, the aquatic organisms have much faster rate of breathing.
Terrestrial organisms take oxygen from the oxygen-rich atmosphere through respiratory organs. Hence, they have much less breathing rate than aquatic organisms.

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

Answer 2:
In cytoplasm Glucose is first broken down into two 3 carbon compounds called as pyruvate by the process known as Glycolysis. Further breakdown takes place in different organism by different processes.

Question 3:
How is oxygen and carbon dioxide transported in human beings?

Answer 3:
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.

Question 4:
How are the lungs designed in human beings to maximize the area for exchange of gases?

Answer 4:
Within the lungs, the air passage divides into smaller and smaller tubes, called bronchi which in turn form bronchioles. The bronchioles terminate in balloon-like structures, called alveoli. The alveoli present in the lungs provide maximum surface for exchange of gases. The alveoli have vary thin walls and contain an extensive network of blood vessels to facilitate exchange of gases

In-Text Questions (Page 110)

Question 1:
What are the components of the transport system in human beings ? What are the functions of these components ?

Answer 1:
The transport system (circulatory system) in human beings mainly consists of heart, blood and blood vessels.

(i) Function of heart : The heart receives deoxygenated blood from the body parts and pumps it to lungs for enriching with oxygen. It receives purified blood from lungs and pumps it around the body.
(ii) Function of blood : Blood transports oxygen, carbon dioxide, digested food, hormones and nitrogeneous waste like urea. It also protects the body from diseases and regulates the body temperature.
(iii) Function of blood vessels : The blood pushed by the heart flows through the blood vessels (arteries, veins and capillaries) and also comes back to the heart through them.

Question 2:
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds ?

Answer 2:
Separation of oxygenated and deoxygenated blood allows good supply of oxygen to the body. This system is useful in animals that have high energy requirement. Mammals and birds constantly need oxygen to get energy to maintain their body temperature constant.

Question 3:
What are the components of the transport system in highly organised plants?

Answer 3:
There are two types of conducting tissues in highly organized plants that carry out transport system 1) Xylem 2) phloem. Xylem conduct water and minerals from roots to rest of the plant parts. Similarly Phloem transports food materials from leaf to other parts of the plant.

Question 4:
How are water and minerals transported in plants?

Answer 4:
Xylems parts tracheids and vessels of roots, stems and leaves are interconnected to form a continuous system of water-conducting channels that reaches all parts of the plant. Transpiration creates a suction pressure which forces water into xylem cells of roots. After this, there will be a steady movement of water from the root xylem to all parts of the plant connected through conducting interconnected water-conducting channels.

Question 5:
How is food transported in plants?

Answer 5:
Food is transported in plants by a special organ called as phloem. Phloem transports food materials from leaf to different parts of a plant. Transportation of food in phloem is achieved by the expenditure of energy from ATP. This increases osmotic pressure in the tissue causing water to move. This pressure moves material in the Phloem to the tissues with less pressure. This is helping in transportation of food material as per the needs. Ex: Sucrose.

In-Text Questions (Page 112)

Question 1:
Describe the structure and functioning of nephrons

Answer 1:
Structure of nephron : Each nephron is composed of two parts. First one is a cup-shaped bag at its upper end which is called Bowman’s capsule.
The Bowman’s capsule contains a bundle of blood capillaries which is called glomerulus. One end of the glomerulus is attached to the renal artery which brings the impure blood containing the urea waste into it. These impurities are filtered. The other part of the nephron is coiled. In this part, the substances like sugar (glucose), amino acid, ions and excess water which are required by the body, are reabsorbed. The substance remained in the nephron is mainly urine containing dissolved urea in water which is expelled from the body through urethra from time to time.

Functions of nephron : Filtration of blood takes place in Bowman’s capsule from the capillaries of glomerulus. The filtrate passes into the tubular part of the nephron. This filtrate contains glucose, amino acids, urea, uric acid, salts and water.
Reabsorption : As the filtrate flows along the tubule, useful substances such as glucose, amino acids, salts and water are selectively reabsorbed into the blood by capillaries surrounding the nephron tubule.
Urine : The filtrate which remained after reabsorption is called urine. Urine contains dissolved nitrogenous waste like urea and uric acid, excess salts and water. Urine is collected from nephrons to carry it to the ureter from where it passes into urinary bladder.

Question 2:
What are the methods used by plants to get rid of excretory products ?

Answer 2:
(i) The plants get rid of gaseous products-through stomata in leaves and lenticels in stems.
(ii) The plants get rid of stored solid and liquid waste by the shedding off leaves, peeling off bark and felling off fruits.
(iii) The plants get rid of wastes by secreting them in the form of gums and resins.
(iv) Plants also excrete some waste substances into the soil around them.

Question 3:
How is the amount of urine produced regulated?

Answer 3:
The amount of urine is regulated by kidney. It depends on the quantity of excess water and wastes dissolved in water.
(i) Quantity of water : When water is abundant in the body tissues, large quantities of dilute urine is excreted out. When water is less in quantity in the body tissues, a small quantity of concentrate urine is excreted.
(ii) Quantity of dissolved wastes : Dissolved wastes, especially nitrogenous wastes, like urea and uric acid and salts are excreted from the body. When there is more quantity of dissolved wastes in the body, more quantity of water is required to excrete them. Therefore, the amount of urine produced increases.
(iii) Hormones : The amount of urine produced is also regulated by certain hormones which control the movement of water and Na+ ions in and out of the nephrons.

Exercise Questions (Page 113)

Question 1:
The kidneys in human beings are a part of the system for
(i) nutrition
(ii) respiration
(iii) excretion
(iv) transportation

Answer 1:
Answer is (c) excretion
The excretory system of human beings (Fig. 6.13) includes a pair of kidneys, a pair of ureters, a urinary bladder and a urethra. Kidneys are located in the abdomen, one on either side of the backbone. Urine produced in the kidneys passes through the ureters into the urinary bladder where it is stored until it is released through the urethra.

Question 2:
The xylem in plants are responsible for
(i) transport of water
(ii) transport of food
(iii) transport of amino acids
(iv) transport of oxygen

Answer 2:
In plants Xylem is responsible for transport of water hence the answer is (a).


Question 3:
The autotrophic mode of nutrition requires
(i) carbon dioxide and water
(ii) chlorophyll
(iii) sunlight
(iv) all of the above

Answer 3:
Autotrophic mode of nutrition requires carob-di-oxide, water, chlorophyll and sunlight from the preparation of food hence the answer is (d) all of the above.

Question 4:
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in
(i) cytoplasm
(ii) mitochondria
(iii) chloroplast
(iv) nucleus

Answer 4:
The breakdown of pyruvate to give carbon dioxide, water and energy takes place in mitochondria. Hence the answer is (b) mitochondria

Question 5:
How are fats digested in our bodies ? Where does this process take place ?

Answer 5:
Digestion of fats takes place in the small intestine.
Bile juice secreted by the liver poured in the intestine along with pancreatic juice. The bile salts present in the bile juice emulsify fhe large globules of fats. Therefore, by enulsification large globules break down into fine globules to provide larger surface area to act upon by the enzymes.
Lipase enzyme present in the pancreatic juice causes break down of emulsified fats. Glands present in the wall of small intestine secrete intestinal juice which contains lipase enzyme that converts fats into fatty acids and glycerol.

Question 6:
What is the role of saliva in the digestion of food ?

Answer 6:
Food we intake is complex in nature, if it is to be absorbed from the alimentary canal then it has to be broken into smaller molecules. This process is mainly done with the help of biological catalysts called enzymes. The saliva contains an enzyme called salivary amylase that breaks down starch, which is a complex molecule to give sugar. The food is mixed thoroughly with saliva and moved around the mouth while chewing the muscular tongue. Hence saliva plays a pivotal in digestion and absorption of food.

Question 7:
What are the necessary conditions for autotrophic nutrition and what are its byproducts?

Answer 7:
Necessary conditions for autotrophic nutrition :
(i) Presence of chlorophyll in the living cells.
(if) Provision of supply of water to green plants or cells of the plant.
(iii) Sufficient sunlight.
(iv) Sufficient supply of carbon dioxide.
By-product of auto tropic nutrition is oxygen.

Question 8:
What are the differences between aerobic and anaerobic respiration ? Name some organisms that use the anaerobic mode of respiration.

Answer 8:


Question 9:
How are the alveoli designed to maximise the exchange of gases ?

Answer 9:
1.The lung is an important part of the body. The passage inside the lungs divides into smaller and smaller tubes, which finally terminate in balloon-like structures, called as alveoli.

2.The alveoli provide a surface where the exchange of gases can take place. The walls of the alveoli usually contains an extensive network of blood vessels. We know that, when we breathe in, we lift our ribs, flatten our diaphragm and chest cavity becomes larger.

3.Because of this action, air is sucked into the lungs and fills the expanded alveoli.

4.The blood brings the essential carbon dioxide from rest of the body and supply it to alveoli; the oxygen in the alveolar air is taken up by the blood in the alveolar blood vessels to be transported to the all other cells of the body. During normal breathing cycle, when air is taken in and let out, the lungs always contain a residual volume of air so that there is sufficient time for oxygen to be absorbed and carbon dioxide to be released.

Question 10:
What would be the consequences of a deficiency of hemoglobin in our bodies?

Answer 10:
Hemoglobin is a protein responsible for transportation of oxygen to the body cells for cellular respiration. Deficiency of Hemoglobin can affect the oxygen carrying capacity of RBC’S. This lead to lack of oxygen in our body cells. Hemoglobin deficiency leads to a disease called as anemia.

Question 11:
Describe double circulation in human beings. Why is it necessary ?

Answer 11:
In our heart blood enters twice and also pumped out twice from the heart. The deoxygenated blood from the body is brought to the right atrium through vena cava from where it is sent to right ventricle. From right ventricle, the blood is pumped to the lungs for oxygenation through pulmonary artery. The oxygenated blood from lungs again enters the left atrium of the heart through pulmonary veins. From left atrium it is send to left ventricle, from where this oxygenated blood is pumped to different parts of body through the arteries. In this way the blood flows through the heart twice, that’s why it is called ‘double circulation’.

Necessity of double circulation: The right side and the left side of the human heart are useful to keep deoxygenated and oxygenated blood from mixing. 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 who constantly need energy to maintain their body temperature.

Question 12:
What are the differences between the transport of materials in xylem and phloem ?

Answer 12:

Question 13:
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.

Answer 13: