Chapter 22: Life Processes-1 Nutrition, Transportation, Respiration, And Excretion

NIOS Class 10 Science Chapter 22 Question Answers

INTEXT QUESTIONS 22.1

1. Give two examples of autotrophs. Why do you call them so?

Ans: Green plants, algae, and bacteria (any two). They are called autotrophs because they perform photosynthesis to manufacture their own food.

2. Why are autotrophs termed ‘producers’ of the food chain?

Ans: They make food through photosynthesis, and all the organisms in a food chain depend on them for their food.

3. Fill in the blanks in the flow chart given below:

Ans:

Types of nutrition: Autotrophic, Heterotrophic
Heterotrophic —Holozoic, Parasitic, Saprophytic/saprotrophic

4. The parasitic and saprotrophic modes of nutrition do not need the three processes required by holozoic animals. Which processes are these?

Ans: Digestion of the ingested food.

5. Classify the following as saprotrophs or parasites:

Leech, yeast, head louse, mushroom

Ans: Parasitic: leech, head louse; saprophytic: Yeast, mushroom.

INTEXT QUESTIONS 22.2

1. In two sentences, justify the term photosynthesis (photo+ synthesis).

Ans: Photo means light, and synthesis means manufacture. It is the process by which plants manufacture food in the presence of light.

2. What makes plants look green? What does the green pigment of plants do for them?

Ans: Chlorophyll. Chlorophyll is necessary for photosynthesis.

3. Glucose and starch are two food substances manufactured in plants. Which one is formed during photosynthesis, and in which form is it stored?

Ans: Glucose is formed during photosynthesis, which is later stored as starch.

4. What role do stomata play in photosynthesis?

Ans: Let in CO₂, from the atmosphere, O₂ is let out to the atmosphere.

INTEXT QUESTIONS 22.3

1. Why should raw vegetables and fruits be a regular item in lunch/dinner?

Ans: Raw vegetables help in bowel movement. They form the ‘roughage’ needed to prevent

constipation.

2. I ate one gram of starchy food, and you ate one gram of fatty food—who shall get more energy, you or me?

Ans: You

3. What is common between vitamins A and D, and B and C, to group them together?

Ans:

Vitamin B and C.—Water-soluble vitamins
Vitamin A, D, E, and K- Fat-soluble vitamins

INTEXT QUESTIONS 22.4

1. Name the enzyme secreted by the stomach that converts proteins into peptones.

Ans: Pepsin

2. What is the movement of muscles of the oesophagus that pushes down food called?

Ans: Peristalsis/ peristaltic movement

3. In which part of the alimentary canal do the pancreas and liver pour their secretions?

Ans: Small intestine

4. Name the enzymes present in the pancreatic juice that digest proteins, carbohydrates, and fats.

Ans:

Trypsin digests proteins
Amylase digests carbohydrates
Lipase digests fats

5. Name the acid that takes part in the digestion process.

Ans: HCl (Hydrochloric acid)

INTEXT QUESTIONS 22.5

1. Give the full form of PEM and name the diseases due to PEM.

Ans: Protein Energy Malnutrition. Marasmus and Kwashiorkor

2. If the diet continuously lacks vitamin A, which disease may be caused?

Ans: Night blindness; Beri Beri, Pellagra; Anaemia, Scurvy; Rickets; Excessive bleeding from wounds (any two)

3. Why does our government frequently advertise the necessity of consuming iodised salt?

Ans: Because it contains Iodine, which is necessary for the formation of thyroid hormones/ prevention of diseases due to a deficiency of thyroid hormone/prevention of goitre.

INTEXT QUESTIONS 22.6

1. Why is a system of transportation/circulation necessary for organisms?

Ans: To circulate O₂ / products of digestion of food/ removal of waste.

2. Which kind of blood vessels are responsible for the exchange of nutrients and respiratory gases between blood and tissues?

Ans: Capillaries

3. What is so special about the heart that it continues beating without getting fatigued?

Ans: Valves prevent mixing of oxygen-laden blood with carbon dioxide-laden blood.

INTEXT QUESTIONS 22.7

1. Which blood cells would you categorise as

(i) transporters of oxygen and carbon dioxide

(ii) enemies of germs that enter the body?

Ans:

(i) RBC

(ii) WBC

2. Sheena has blood group O+, and Veena has AB+. Whose blood would be useful if it has to be transfused into an accident victim of an unknown blood group, and why?

Ans: Sheena’s blood because the O group is a universal donor.

3. What makes RBCs look red? What is the role of this pigment?

Ans: Haemoglobin. It carries oxygen to tissues and brings back carbon dioxide from tissues.

4. In which function is lymph similar to blood?

Ans: Preventing the body from infections; returns proteins and fluid from circulation to tissues.

INTEXT QUESTIONS 22.8

1. Why does the trachea not deflate (collapse) during exhalation?

Ans: It is supported by rings of cartilage.

2. The sequence of parts of the human respiratory system is jumbled. Place them in the right order. Nasal cavity, trachea, pharynx, internal nostrils, bronchi, lungs.

Ans: Nasal Cavities; Internal nostrils; Pharynx; Trachea; Bronchi; Lungs.

3. You have learnt in Physics that when volume increases, pressure decreases. How does this principle find a place in the process of breathing?

Ans: During inhalation, the chest cavity enlarges and air pressure in it decreases, so air from outside rushes in.

The diaphragm straightens out.
Ribs are raised upward and outward.
Volume of chest cavity increases; pressure of air is it decreases
Air rushes into the alveoli

4. Once oxygen reaches cells, which of its organelles takes over respiration?

Ans: Mitochondria

5. Why are the alveoli supplied with capillaries?

Ans: For the exchange of gases (O₂ and CO₂)

INTEXT QUESTIONS 22.9

1. Name the organ of the excretory system, which stores urine before its removal from the body.

Ans: Urinary bladder

2. Draw a rough diagram of the nephron and label only the part where filtration occurs.

Ans:

3. What happens to the useful substances that move into the glomerulus along with nitrogenous waste?

Ans: Get reabsorbed into the blood capillaries surrounding the tubule.

TERMINAL EXERCISES

1. Multiple-choice type questions.

i. Rickets is caused due to deficiency of:

a) Iron

b) Vitamin D

c) Proteins

d) Carbohydrates

Ans: b) Vitamin D

ii. One gram of a substance was oxidised. The energy released amounted to 9.0Kcal. The substance was of the type:

a) Carbohydrates

b) Fats

c) Vitamins

d) Proteins

Ans: b) Fats

iii. A person living in the hilly regions of Shimla developed swelling in his neck region. The doctor said his thyroid gland got swollen. Name the nutrient deficient in his diet.

a) Calcium

b) Iron

c) Phosphorus

d) Iodine

Ans: d) Iodine

iv. The vitamin that helps in the clotting of blood is:

a) Vitamin A

b) Vitamin D

c) Vitamin E

d) Vitamin K

Ans: d) Vitamin K

v. In human beings, gas exchange between the environment and the body takes place in the:

a) larynx

b) bronchi

c) alveoli

d) trachea

Ans: c) alveoli

vi. RBCs of human beings who live in high altitude regions:

a) increase in number

b) decrease in number

c) decrease in size

d) increase in size.

Ans: a) increase in number

vii. Lungs have a large number of alveoli for:

a) maintaining a spongy texture and proper shape.

b) more surface area for diffusion of gases.

c) more nerve supply.

d) more space to increase volume of inspired air.

Ans: b) more surface area for diffusion of gases.

viii. The main function of lymph is to:

a) transport O₂to the brain.

b) transport CO₂ to lungs.

c) return interstitial fluid to blood.

d) return RBCs and WBCs to lymph vessels.

Ans: c) return interstitial fluid to blood.

2. Name the following.

i. A fluid that transports fatty acids and glycerol.

ii. The valve is present in between the chambers on the right side of the human heart.

iii. The respiratory pigment present in RBCs.

iv. The iron contains pigment in RBCs.

v. The phase of cardiac cycle in which the auricles contract.

Ans:

Lymph
Tricuspid valve
Hemoglobin
Hemoglobin
Atrial systole

3. Give one point of difference between the following.

1. Autotrophic and heterotrophic nutrition

2. Breathing and respiration

3. Arteries and veins

4. Blood and lymph

5. Auricular systole and ventricular systole

Ans:

1. Autotrophic and heterotrophic nutrition: Autotrophic nutrition, plants manufacture their own food. In heterotrophic nutrition, organisms depend on other organisms for their food.
2. Breathing and respiration: Breathing provides oxygen to the cells of our body for the oxidation of food to generate energy for various activities. Respiration involves the oxidation of food and the release of energy, which takes place in the cells along with respiratory gaseous exchange.
3. Arteries and veins: Arteries carry blood from the heart to various parts of the body. Veins bring blood from various parts of the body to the heart.
4. Blood and lymph: Blood is a connective tissue that circulates throughout the body. Lymph is also a circulatory fluid and flows in the lymph vessels.
5. Auricular systole and ventricular systole: Auricular systole pushes blood from the atrial chamber to the ventricle. Ventricular systole is stronger and pushes blood out of the heart.

4. Match the columns A and B.

COLUMN A	COLUMN B
1. Sponge-like organs located in the chest cavity	a. trachea
2. Chamber acting as a common passage for food	b. Bronchioles and air
3. Elastic tissue that forms a flap over the top of	c. epiglottis the larynx
4. Main passageway to the lungs	d. pharynx
5. Small tubes that branch from the bronchi	e. bronchi
6. Small air sacs in the lungs	f. lungs
	g. alveoli
	h. Larynx

Ans:

f. lungs
d. Pharynx
c. epiglottis
a. Trachea
e. Bronchi
g. Alveoli

5. Given below is an example of a certain structure and its function.

‘Kidney and excretion’

Fill in the blanks on a similar pattern.

1. Alveoli and ____________

2. Diaphragm and ____________

3. ‘C’-shaped cartilage rings and ____________

4. Erythrocyte and ____________

5. Left ventricle and ____________

6. Pacemaker and ____________

Ans:

1. Alveoli and Gas Exchange

2. Diaphragm and Breathing

3. ‘C’-shaped cartilage rings and Protection of trachea from collapsing

4. Erythrocyte and Oxygen Transport

5. Left ventricle and pumping oxygenated blood

6. Pacemaker and Heartbeat Regulation

6. What is a balanced diet? Name three items of a diet that provide three different nutrients?

Ans: A balanced diet contains adequate amounts of essential nutrients such as carbohydrates, fats, proteins, vitamins, minerals, and water. The proportion may depend on age, sex, pregnancy, etc.

7. What are the main steps of photosynthesis? Is sunlight essential for photosynthesis, and why?

Ans: Photosynthesis occurs in two steps— The dark reaction and the light reaction that occur simultaneously.

(i) Light reaction: In the light reaction, light is captured by the chloroplast. The reaction occurs in the chloroplasts.
(ii) Dark reaction: In the dark reaction, glucose is formed. Dark reaction occurs in chloroplasts.

Yes, sunlight is essential for photosynthesis as it provides the necessary energy for photosynthesis to occur.

8. A patient complains of lack of appetite, exhaustion, and is losing weight. Diagnose the deficiency. What kind of diet would you suggest for the patient?

Ans: The patient has malnutrition that lacks several essential nutrients. The patient should take a balanced diet that contains carbohydrates, proteins, fats, and other vitamins that provide the necessary nourishment for the body.

9. Deficiency of which vitamin causes night blindness? What would you suggest to prevent this deficiency?

Ans: Deficiency of vitamin A causes night blindness. Including plenty of carrots can improve the condition as it is rich in this vitamin.

10. Where does the digestion of starch, proteins, and fats take place, and what is the role played in digestion by liver and pancreas?

Ans: Digestion of these starts at,

Starch- Mouth where amylase in saliva breaks down starch into sugar.
Protein- Starts in the stomach, where the pepsin breaks it down into smaller fragments
Fat- Digestion starts in the small intestine.

The liver secretes bile juice, and the pancreas secretes other necessary enzymes that help with the digestion of starch, proteins, and fats.

11. Which component in your diet will not be digested if the enzyme lipase is not secreted?

Ans: Lipase is the enzyme that digests fat and converts it into fatty acids and glycerol. If lipase is not secreted, it affects the digestion of fats.

12. Explain how oxygen leaves the blood from the tissue capillaries and carbon dioxide enters the blood in the tissue capillaries.

Ans: Blood capillaries on alveoli pick up oxygen from the alveoli, and carbon dioxide brought by the capillaries from the tissues is exchanged for oxygen. Oxygen diffuses into alveoli.

In the tissues, oxygen gets used up, and carbon dioxide is accumulated, which is now exchanged for oxygen in the blood. The carbon dioxide picked up by blood from tissues is carried to the heart by veins.

13. Explain the usefulness of large surface area provided by alveoli for respiration in human beings.

Ans: Gaseous exchange in the alveoli happens due to diffusion. The larger surface area provides space for the presence of a large number of capillaries, thus a larger quantity of gases is exchanged.

14. Why do arteries have a thick or elastic wall?

Ans: In the arteries, the force of blood passing through is much higher. Arterial walls are elastic and thick to withstand this pressure and allow smoother contractions.

15. What are the four types of blood groups present in humans? Prepare a table with two columns to show the different human blood groups and names of compatible blood groups in the other column.

Ans: The four types of blood groups in humans are named A, B, AB, and O. Here is the compatible blood groups for each blood group.