Life Processes Class 10 Important Questions with Answers Science Chapter 6 - CBSE Tuts (2023)

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Class 10 Science Chapter 6 Important Questions with Answers Life Processes

Class 10 Chemistry Chapter 6 Important Questions with Answers Life Processes

Life Processes Class 10 Important Questions Very Short Answer Type

Question 1.
Name the form in which the energy derived from the food is stored in humans. (2014)
Answer:
Chemical energy (ATP).

Question 2.
Define photosynthesis. (2015)
Answer:
The process by which green plants make their own food (like glucose) from carbon dioxide and water by using solar energy in the presence of chlorophyll is called photosynthesis.

Life Processes Class 10 Important Questions Short Answer Type I

Question 1.
Why do herbivores have longer, small intestine than carnivores? (2014)
Answer:
The length of the small intestine differs in various animals depending on the type of food they eat. Cellulose is a carbohydrate food which is digested with difficulty. So the herbivorous animals like cows which eat grass need a longer small intestine to allow the cellulose present in grass to be digested completely.

Question 2.
(i) Name two waste products which are stored in old xylem in plants.
(ii) Name the process by which plants get rid of excess water. Name the pores through which this process takes place. (2015)
Answer:
(i) Resin and gums are the two wastes which are stored in old xylem in plants.
(ii)

• Transpiration is the process by which plants get rid of excess water.
• Stomatal pores are the pores through which transpiration takes place.

Question 3.
Name the type of asexual reproduction in which two individuals are formed from a single parent and the parental identity is lost. Write the first step from where such a type of reproduction begins. Draw first two stages of this reproduction. (2017 D)
Answer:
The type of asexual reproduction in which two individuals are formed from a single parent and parental identity is lost is called Binary fission.
The first step of this reproduction is elongation of cells and its nucleus.

Question 4.
Draw in sequence (showing the four stages), the process of binary fission in Amoeba. (2017 OD)
Answer:

Life Processes Class 10 Important Questions Short Answer Type II

Question 1.
(a) Explain with the help of diagram, how amoeba takes its nutrition.
(b) Assume that you are a veterinary surgeon and you had removed a good length of the small intestine of a bear that was suffering from an intestinal tumor. Now, would you suggest a plant based or a meat based diet for the bear after its recovery? Give reason for your answer.
(c) Do you think plant based food should be preferred over non-vegetarian food? (2012)
Answer:
(a) Amoeba takes in the food particles with the help of its finger like projections called pseudopodia. Inside its cell a food vacuole is formed around the food particle. Inside the food vacuole, complex substances are broken down into simpler ones which are then diffused into the cell cytoplasm. The remaining undigested material is sent to the surface of the cell and thrown out. The process of nutrition in Amoeba is called Endocytosis.

(b) I would suggest a meat based diet for the bear after its recovery because meat based food can be digested easily in a smaller sized small intestine.
(c) We should encourage vegetarian food over non-vegetarian food.

Question 2.
Name three different glands associated with the digestive system in humans. Also name their secretions. (2012)
Answer:
Three glands associated with the digestive system are as follows:
1. Salivary glands in the mouth produce saliva. Saliva contains an enzyme called salivary amylase which digests the starch present in food into sugar.

2. Liver is the largest gland which secretes bile and pours its secretion in the duodenum (part of the small intestine). Bile makes the acidic food coming from the stomach alkaline so that pancreatic enzymes can act on it. Bile salts also break the fats present in the food into small globules.

3. Pancreas is also a large gland which secretes pancreatic juice into the duodenum. Pancreatic juice contains

• pancreatic amylase which breaks down the starch.
• Trypsin digests the protein.
• lipase which breaks down the emulsified fats.
• Pancreatic juice acts on alkaline medium.

Question 3.
(a) What is translocation? Why is it essential for plants? (2013)
(b) Where are the substances translocated by the phloem delivered?
Answer:
(a) The movement of food from leaves to other parts of the plant in phloem is called translocation. The translocation is necessary because every part of the plant needs food for obtaining energy, for building its parts and maintaining its life.

(b) The movement of food in phloem is transported upwards or downwards depending on the needs of the plant, for example, in spring, even the sugar stored in the root or stem tissue of a plant would be transported through phloem to the buds which need energy to grow.

Question 4.
(i) Which organ secretes a hormone when the blood sugar rises? Name a digestive enzyme released by this organ.
(ii) Why pancreas helps in digestion and also regulates blood sugar? (2013)
Answer:
(i) Pancreas secretes insulin (hormone) when the blood sugar rises. Pancreas secretes pancreatic juice which contains ciigestive enzymes.

(ii) Pancreas secretes enzymes like pancreatic amylase which breaks down starch, trypsin which breaks down proteins and lipase breaks down emulsified fats.
Pancreas also secretes a hormone called insulin which controls the metabolism of sugar. Therefore it lowers the blood sugar level. So pancreas is both an exocrine and an endocrine gland.

Question 5.
Give reasons for the following:
(a) Arteries are thick walled.
(b) Blood goes only once through the heart in fishes.
(c) Plants have low energy needs. (2013)
Answer:
(a) Arteries have thick walls because these vessels carry blood from the heart to all the parts of the body and blood emerges from the heart under high pressure.

(b) A fish has a two chambered heart and has gills to oxygenate blood. In a fish, the heart pumps deoxygenated blood to gills where oxygenation of blood takes place. The oxygenated blood from the gills is supplied to the body parts of the fish where oxygen is utilised and carbon dioxide enters into it, making it deoxygenated. This deoxygenated blood returns to the heart to be pumped into gills again. Thus blood passes through the heart of fish only once in one complete cycle.

(c) Plants are fixed at a place and do not show any locomotion. Plants are less active. Their cells do not need to be supplied with materials so quickly. Therefore plants have low energy needs and respire at a slow rate.

Question 6.
(a) With the help of a neat labelled diagram show how amoeba captures its food?
(b) What is the mode of nutrition in amoeba? (2013)
Answer:
(a)

(b) Mode of nutrition in Amoeba is holozoic.

Question 7.
(a) What happens to the heart when muscles work harder?
(b) Which body system is directly affected when a person has heart disease?
(c) Which cells increase in number during infection? (2013)
Answer:
(a) When muscles work harder, the heart beats faster because the muscles need more energy than the
normal requirement. The faster beating of heart pumps blood more rapidly to the muscles which supplies more oxygen to the muscle cells for rapid respiration to produce more energy.
(b) Human circulatory system is directly affected when a person has heart disease.
(c) White blood cells (WBCs) increase in number during infection.

Question 8.
The rate of breathing in aquatic organisms is much faster than that seen in terrestrial organisms. Give reason. State the pathway of air from nostrils to the lungs in human beings. (2014)
Answer:
The animals which live in water (aquatic animals) use the oxygen dissolved in water to carry out respiration. Since the amount of dissolved oxygen in water is low as compared to the amount of oxygen in the air, therefore, the rate of breathing in aquatic animals is much faster than in terrestrial animals. A faster rate of breathing provides more oxygen to aquatic animals.

Pathway of air in human beings:
Nostrils → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Lungs

Question 9.
(a) State the purpose of formation of urine. (2014)
(b) What will happen if there is no tubular reabsorption in the nephrons of kidney?
Answer:
(a)

• Urea is produced as a waste by decomposition of unused proteins in the liver. Our body must get rid of these waste materials because their accumulation in the body is poisonous and harmful for us.
• Kidneys are the organs which 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.

(b) During filtration, the substances like glucose, amino acids, salts, water and urea etc. present in the blood pass into Bowman’s capsule and then enter the tubule of nephron. When the filtrate containing useful substances as well as the waste substances passes through the tubule, the useful substances like glucose, amino acids, most salts and most water etc. are reabsorbed into blood through blood capillaries surrounding the tubule.

Only the waste substances like urea, some unwanted salts and excess water remain behind in the tubule. Therefore, reabsorption in the nephrons of kidneys is important.

Question 10.
Explain how water and minerals are transported in plants? (2014)
Answer:
Most plants secure their water and minerals from their roots. Minerals travel dissolved in water. Water and minerals are transported through xylem cells from the soil to the leaves. The xylem cells of roots, stem and leaves are interconnected to form a conducting channel. The root cells take ions from the soil.

This creates a difference between the concentration of ions of roots and soil. Therefore, there is a steady movement of water into xylem. An osmotic pressure is formed and water and minerals are transported form one cell to the other due to osmosis. The continuous loss of water takes place due to transpiration.

Question 11.
Draw a neat diagram of excretory system of human beings and label on it:
Kidney, Urinary bladder, Ureter (2014)
Answer:
Excretory system:

Question 12.
Name any three glands associated with digestion in humans. Write the names of enzymes secreted by them. (2015)
Answer:

Question 13.
Bile juice does not contain any enzyme but bile salts are important for digestion and absorption of fats. State reason. (2015)
Answer:
Bile is a digestive juice secreted by the liver. Although it does not contain any digestive enzymes, it plays an important role in the digestion of fats.
Bile is alkaline and contains salts which help to emulsify or break the fats (or lipids) present in the food. Thus, bile performs two functions:

• Makes the acidic food coming from the stomach alkaline so that pancreatic enzymes can act on it.
• Bile salts break the fats present in the food into small globules making it easy for the enzymes to act and digest them.

Question 14.
(a) State reason for the following: (2015)
(i) Rings of cartilage are present in the trachea.
(ii) Plants look green in colour.
(b) Write other names of the following:
(i) Alveolar sac
(ii) Voice box
Answer:
(a) (i) The air coming from the nostrils during breathing passes through the trachea. The trachea does
not collapse even when there is no air in it because it is supported by rings of soft cartilages.
(ii) Plants look green in colour because of the presence of a green pigment called chlorophyll in their chloroplasts.

(b) (i) Alveolar sac → Alveoli
(ii) Voice box → Larynx

Question 15.
Describe the structure and functioning of nephron. (2017 D)
Answer:
Structure of nephron. Nephron is the basic filtration unit in the kidney. It consists of a tubule which is connected with a collecting duct at one end and a cup shaped structure at the other end, called Bowman’s capsule.

Every Bowman’s capsule contains a cluster of capillaries called glomerulus within the cup-shaped structure. The blood enters into glomerulus through afferent arteriole of renal artery and leaves it through efferent arteriole.

Basic functions of Nephrons:

• Filtration: Filtration of the blood takes place in Bowman’s capsule in the capillaries of the glomerulus. Then this filtrate passes into the tubular part of the nephron. The filtrate contains glucose, amino acids, urea and uric acid and a large amount of water.
• Reabsorption: The filtrate flows along the tubule and useful substances such as glucose, amino acids, salts and some water are re-absorbed into the blood by the capillaries surrounding the nephron tubule.
• Urine: The filtrate which remains after the re-absorption is called the urine, which is collected from nephron by the collecting duct to carry it to the urinary bladder and then to the urethra.

Question 16.
Explain the nutrition process in Amoeba. (2017 OD)
Answer:
Amoeba takes in the food particles with the help of its finger like projections called pseudopodia. Inside its cell a food vacuole is formed around the food particle. Inside the food vacuole, complex substances are broken down into simpler ones which are then diffused into the cell cytoplasm. The remaining undigested material is sent to the surface of the cell and thrown out.
This process of nutrition in Amoeba is called Endocytosis.

Question 17.
Draw a labelled diagram of human heart. (2017 OD)
Answer:

Life Processes Class 10 Important Questions Long Answer Type

Question 1.
Draw the diagram of sectional view of human heart and on it name and label the following parts:
(a) The chamber of the heart that pumps out deoxygenated blood.
(b) The blood vessel that carries away oxygenated blood from the heart.
(c) The blood vessel that receives deoxygenated blood from the lower part of our body. (2012)
Answer:

(a) The chamber of the heart that pumps out deoxygenated blood – Right ventricle
(b) The blood vessel that carries away oxygenated blood from the heart – Aorta
(c) The blood vessel that receives deoxygenated blood from the lower part of our body – Inferior Vena Cava

Question 2.
(a) Draw a diagram of human alimentary canal and label the following parts:
(i) largest gland.
(ii) Gland that secretes digestive enzymes and hormone.
(iii) Part where HCl is produced.
(iv) Part where digested food is absorbed.
(b) What are villi? Explain their function in the digestive system. (2012)
Answer:
(a) (i) Largest gland – Liver
(ii) Gland that secretes digestive enzymes and hormone – Pancreas
(iii) Part where HCl is produced – Stomach
(iv) Part where digested food is absorbed – Small intestine

(b) The small intestine is especially adapted for absorption of digested food. The inner surface of small intestine has millions of tiny, finger like projections called villi which provide the inner walls of small intestine a very large surface area. The large surface area helps in the rapid absorption of digested food. The villi are richly supplied with blood vessels which take the absorbed food to each and every cell of the body.

Question 3.
Draw the human respiratory system and label the following parts: (2013)
(a) Trachea (b) Alveoli (c) Respiratory bronchioles (d) Larynx
Describe in brief the role of lungs in the exchange of gases.
Answer:
Human respiratory system:

Role of lungs:
1. When we breathe in air, the diaphragm contracts which results in the increase of chest cavity. Due to this expansion of chest cavity, the air pressure in the lungs decreases. Thus, air from outside rushes into the lungs through nostrils, trachea and bronchi. Thus sacs of lungs get filled with air when we breathe in. The exchange of gases between alveoli and blood takes place by the process of diffusion.

2. Now the air present in air sacs of the lungs is rich in CO₂. When we breathe out air, the diaphragm relaxes which results in the decrease of chest cavity. This contraction pushes the air from the lungs into the trachea, nostrils and then out of the body into air. Breathing in of air is called inhalation and breathing out of air is called exhalation.

Question 4.
(a) Compare the length of small intestine in herbivore and carnivore animal. (2013)
(b) Mention any two structural modifications in small intestine which helps in absorption.
Answer:
(a) The length of the small intestine differs in various animals depending on the type of food they eat. For example, cellulose is a carbohydrate food which is digested with difficulty. So, the herbivorous animals like cow which eat grass need a longer ‘small intestine’ to allow the cellulose present in grass to be digested completely. On the other hand, meat is a food which is easier to digest. So, the carnivorous animals like tigers which eat meat, have a shorter ‘small intestine’.

(b) The inner surface of small intestine has millions of tiny, finger-like projections called villi. The presence of villi gives the inner walls of the small intestine a very large surface area and the large surface area of small intestine helps in the rapid absorption of digested food.

Question 5.
(a) Explain how the separation of oxygenated and deoxygenated blood is useful in humans?
(b) Why is double circulation of blood necessary in humans? (2015)
Answer:
(a) Humans have a four chambered heart which consists of two atria and two ventricles. In a four chambered heart, the left side and right side of the heart are completely separated to prevent the oxygenated blood from mixing with deoxygenated blood. Such a separation allows a highly efficient supply of oxygen to the body cells which is necessary for producing a lot of energy. This energy is useful for a warm blooded animal (like humans) which has high energy needs to maintain body temperature.

(b) All the animals having four chambered hearts have double circulation in which the blood passes through the heart ‘twice’ in one complete cycle of the body. This ensures the separation of oxygenated blood from deoxygenated blood.

Explanation:
Double circulation. The blood travels twice through the heart in one complete cycle of the body and is called double circulation. It involves two circulations:

1. Pulmonary circulation. The pathway of the blood from the heart to the lungs and back to the heart is called pulmonary circulation. It is a small circulation. Deoxygenated blood in the right ventricle flows into the vascular system of the lungs, becomes oxygenated and returns to the hearts left atrium through pulmonary veins.

2. Systemic circulation. The pathway of the blood from the heart to the rest of the body and back to the heart is called systemic circulation. It is a large circulation. Left ventricle sends the blood into the aorta. Aorta divides into arteries, arterioles and capillaries and supplies oxygenated blood to various parts of the body. From there the deoxygenated blood is collected by venules, which join to form veins and finally vena cava and pours blood back into the right atrium.

Question 6.
Describe double circulation in human beings. (2017 D)
(a) Why is it necessary?
(b) How are arteries different from veins?
Answer:
(a) Double circulation of blood means, that the blood enters twice in the heart during its one circulation in other parts of the body. First time oxygenated blood from lungs enters the left atrium and second I time de-oxygenated blood enters the right atrium through two main vena cava. Double circulation of blood is necessary to separate the oxygenated blood from the de-oxygenated blood to provide more energy for efficient working of body organs.

(b)
Arteries:

1. Arteries are thick walled.
2. Arteries carry blooci from the heart to different organs of the body.
3. Arteries do not have valves.
4. Arteries are deeply placed.

Veins:

1. Veins are thin walled.
2. Veins carry the blood from body organs to the heart.
3. Veins have valves in them.
4. Veins are superficially placed.