Respiration in Organisms For Class 7 Science MCQ Questions

Q 1 –  Sometimes when we do heavy exercise, anaerobic respiration takes place in our muscle cells. What is produced during this process?
(a) alcohol and lactic acid
(b) alcohol and CO2
(c) lactic acid and CO2
(d) lactic acid only

Ans. (d) lactic acid only

Q 2 –  Yeast is used in wine and beer industries because it respires.
(a) aerobically producing oxygen
(b) aerobically producing alcohol
(c) anaerobically producing alcohol
(d) anaerobically producing CO2

Ans. (c) anaerobically producing alcohol

Q 3 –  During the process of exhalation, the ribs move
(a) down and inwards
(b) up and inwards
(c) down and outwards
(d) up and outward

Ans.  (a) down and inwards

Q 4 –  Breathing is a process that
(i) provides O2 to the body.
(ii) breaks down food to release energy.
(iii) helps the body to get rid of CO2
(iv) produces water in the cells.
Which of the following gives the correct combination of functions of breathing?
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iii)
(d) (ii) and (iv)

Ans.  (c) (i) and (iii)

Q 5 –  Which are the gases involved in breathing?
(a) O2 and NO2
(b) O2 and SO2
(c) O2 and O3
(d) O2 and CO2

Ans. (d) O2 and CO2

Q 6 –  Name the organ of the body in which the blood is oxygenated.
(a) Heart
(b) Lungs
(c) Lever
(d) Pancreas

Ans.  (b) Lungs

Q 7 –  After heavy exercise, due to the accumulation of which substance we get muscle cramps ?
(a) Malaic acid
(b) Fumaric acid
(c) Lipoic acid
(d) Lactic acid

Ans.  (d) Lactic acid

Q 8 –  Yeasts are used in
(a) wine and beer industry
(b) bakery
(c) in both
(d) none of these

Ans. (a) wine and beer industry

Q 9 –  Breathing rate in human beings in normal condition is
(a) 12-15 times in a minute
(b) 15-18 times in a minute
(c) 18-22 times in a minute
(d) 22-25 times in a minute

Ans.  (b) 15-18 times in a minute

Q 10- –  All organisms are made of small microscopic units which cannot be seen with the naked eyes, called
(a) animals
(b) cells
(c) tissues
(d) organs

Ans. (b) cells

Q 11 –  Organisms get energy through
(a) food
(b) eating
(c) sleeping
(d) none of these

Ans. (a) food

Q 11 –  Cellular respiration is carried out in the
(a) cells
(b) organs
(c) tissues
(d) muscles

Ans. (a) cells

Q 12 –  The process of breakdown of food in the cell is known as
(a) breakdown process
(b) cellular respiration
(c) food breakdown
(d) none of these

Ans. (b) cellular respiration

Q 13 –  An example of aerobes is
(a) cat
(b) dog
(c) human being
(d) all of these

Ans. (d) all of these

Q 14 –  When breakdown of glucose occurs with the use of oxygen, it is called
(a) anaerobic respiration
(b) aerobic respiration
(c) regular respiration
(d) all of these

Ans. (b) aerobic respiration

Q 15 –  Name the type of respiration which causes muscle cramps.
(a) Aerobic respiration
(b) Anaerobic respiration
(c) Both (a) and (b)
(d) None of these

Ans. (b) Anaerobic respiration

Q 16 –  Name the term which means ‘taking in of air rich in oxygen into the body’.
(a) Exhalation
(b) Inhalation
(c) Breathing
(d) Respiration

Ans. (b) Inhalation

Q 17 –  Which gas is given out during exhalation?
(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
(d) All of these

Ans. (c) Carbon dioxide

Q 18 –  The gills help the fish to
(a) take in oxygen from air
(b) take in oxygen dissolved in water
(c) absorb nutrients present in water
(d) release waste substance in water

Ans. (b) take in oxygen dissolved in water

Q 19 –  Yeast are used to make
(a) curd
(b) wine and beer
(c) bakery items
(d) both (b) and (c)

Ans. (d) both (b) and (c)

Q 20 –  Earthworms breathe through
(a) skin
(b) legs
(c) trachea
(d) nose

Ans. (a) skin

Q 21 –  The organ through which fishes breathe is
(a) nose
(b) gills
(c) skin
(d) spiracles

Ans. (b) gills

Q 22 –  In the cells, oxygen is used to break down glucose into
(a) carbon dioxide, water and energy
(b) fats
(c) alcohol, carbon dioxide and energy
(d) lactic acid, water and energy

Ans. (a) carbon dioxide, water and energy

Q 23 –  Cockroaches breathe by using an organ called
(a) nose
(b) tracheae
(c) both (a) and (b)
(d) none of these

Ans. (b) tracheae

Q 24 –  The most common substrate for respiration is
(a) fats
(b) amino acids
(c) glucose
(d) sucrose

Ans. (c) glucose

Q 25 –  Organism which respires in the absences of oxygen is called a/an
(a) microbe
(b) anaerobe
(c) aerobic
(d) none of these

Ans. (b) anaerobe

Q 26 –  During inspiration or inhalation, in lungs
(a) volume decreases, pressure increases
(b) volume increases, pressure decreases
(c) volume decreases, pressure decreases
(d) volume increases, pressure increases

Ans. (b) volume increases, pressure decreases

Q 27 –  Insects have a special network of tubes called
(a) tracheae
(b) gills
(c) spiracles
(d) lungs

Ans. (a) tracheae         

Q 28 –  The major source of oxygen for the aquatic animals is
(a) atmosphere
(b) water
(c) soil
(d) none of these

Ans. (c) soil

Q 29 –  Primary organ of human respiratory system is
(a) lung
(b) liver
(c) heart
(d) pharynx

Ans. (a) lung

Q 30 –  When breakdown of glucose occurs in the presence of oxygen, the respiration is called
(a) anaerobic
(b) microbe
(c) aerobic
(d) none of these

Ans. (d) spiracles

Q 31 –  The process of breakdown of food in the cell with the release of energy is called
(a) cellular respiration
(b) aerobic respiration
(c) anaerobic respiration
(d) none of these

Ans. (a) cellular respiration

Q 32 –  In earthworm, the exchange of gases occurs through
(a) lungs
(b) moist skin
(c) gills
(d) trachea

Ans. (b) moist skin

Q 33 –  Plants breathe through tiny pores in the leaves called
(a) stomata
(b) leaf blade
(c) pores
(d) trachea

Ans. (a) stomata

Q 34 –  Which of the following animals breathe through skin as well as through lungs?
(a) Fish
(b) Earthworm
(c) Cockroach
(d) Frog

Ans. (d) Frog