English Medium Class 10 - CBSE Question Bank Solutions for Science

Which of the following is the correct sequence of air passage during inhalation?

(a) nostrils → larynx → pharynx → trachea → lungs
(b) nasal passage → trachea → pharynx → larynx → alveoli
(c) larynx → nostrils → pharynx → lungs
(d) nostrils → pharynx → larynx → trachea → alevoli

Lack of oxygen in muscles often leads to cramps in the legs of sprinters. This is due to the conversion of pyruvate to:

During the deficiency of oxygen in tissues of human beings, pyruvic acid is converted into lactic acid in:

Which of the following statements are correct?
(i) pyruvate can be converted into ethanol and carbon dioxide by yeast
(ii) fermentation takes place in the case of aerobic bacteria
(iii) fermentation takes place in mitochondria
(iv) fermentation is a form of anaerobic respiration

Which of the following statements are true about respiration?
(i) during inhalation, ribs move inward and diaphragm is raised.
(ii) the gaseous exchange takes place in the alveoli.
(iii) haemoglobin has greater affinity for carbon dioxide than oxygen.
(iv) alveoli increase surface area of the exchange of gases

Which of the following is known as the energy currency of the cells in biology?

The two organisms which breath only through their moist skin are:

One of the following animals does not use tracheae as the respiratory organs. This animal is:

The breathing and respiration in woody stem of a plant takes place through:

The photosynthesis in a plant is not taking place during the day time if the plant is releasing:

One of the following organisms does not depend on the simple diffusion of gases for breathing and respiration. This organism is:

During marathon, we sometimes get painful contractions of leg muscles due to the accumulation of one of the following in leg muscles. This is:

Which of the following is most likely to have a much higher breathing rate?

In cockroaches, air enters the body through:

During the respiration of an organism A, 1 molecule of glucose produces 2 ATP molecules whereas in the respiration of another organism B, 1 molecule of glucose produces 38 ATP molecules.

(a) Which organism is undergoing aerobic respiration?
(b) Which organism is undergoing anaerobic respiration?
(c) Which type of organism, A or B, can convert glucose into alcohol?
(d) Name one organism which behaves like A.
(e) Name two organisms which behave like B.

A, B and C are three living organisms. The organism A is a unicellullar fungus which can live without air. It is used in the commercial production of an organic compound P from molasses. The organism B is a unicellular animal which lives in water and feeds and moves by using pseudopodia. It breathes through an organelle Q. The organism C is a tiny animal which acts as a carrier of malarial parasite. It breathes and respires through a kind of tiny holes R and air-tubes S in its body.

(a) What are organisms (i) A (ii) B, and (iii) C?
(b) Name (i) P (ii) Q (iii) R, and (iv) S.
(c) Which organism/organisms undergo aerobic respiration?
(d) Which organism/organisms undergo anaerobic respiration?

There are five animals P, Q, R, S and T. The animal P always lives in water and has gills for breathing. The animal Q can stay in water as well as on land and can breathe both, through moist skin and lungs. The animal R lives in soil and breathes only through its skin. The animal S lives on land and breathes through spiracles and tracheae. And animal T lives in water and breathes through its cell membrane.

(a) Which of the animals could be Amoeba?
(b) Which of the animals could be frog?
(c) Which animal could be fish?
(d) Which animal could be grasshopper?
(e) Which animal could be earthworm?

Some sugar solution is taken in a test-tube and a little of substance X in powder form is added to it. The mouth of test-tube is closed with a cork and allowed to stand for sometime. On opening the cork, a characteristic smell of substance Y is obtained and a gas Z is also observed to be formed. The gas Z extinguishes a burning matchstick.

(a) What could be (i) X, (ii) Y, and (iii) Z?

(b) What is the process of converting sugar into substance Y by the action of X known as?

(c) What type of respiration is exhibited by X in the above process?

Consider the following chemical reactions which take place in different organisms/tissues under various conditions:

(i) Glucose →   Respiration    "> `"Respiration"/"">` Ethanol + Carbon dioxide + Energy
(ii) Glucose→   Respiration    "> `"Respiration"/"">` Carbon dioxide + Water + Energy
(iii) Glucose →   Respiration    ">→   Respiration    ">`"Respiration"/"">`  Lactic acid + Energy

(a) Name one organism which respires according to equation (i) above.
(b) Name one organism which respires according to equation (ii) above.
(c) When and where does respiration represented by equation (iii) above take place?
(d) Which equation/equations represent aerobic respiration?
(e) Which equation/equations represent anaerobic respiration?
(f) Which of the above reactions produces the maximum amount of energy?

When a person breathes in the air, the air enters into his body through an organ A having two holes B in it. The air then passes through the pharynx and larynx and enters into tube C. The tube C divides into two smaller tubes D at its lower end. The two smaller tubes are attached to two respiratory organs E. Each smaller tube divides inside the organs E to form a large number of still smaller tubes called F. The smallest tubes F have air-sacs G at their ends in which gaseous exchange takes place in the body of the person. What are A, B, C, D, E, F, and G?