Respiration in Organisms Class 7 MCQ Science Chapter 6

Class 7 Science Chapter 6 MCQ Respiration in Organisms

MCQ on Respiration in Organisms Class 7

I. Multiple Choice Questions (1 Mark)

Select and write the most appropriate option out of the four options given

Question 1.
Select the correct statement regarding cellular respiration.
A) It is a biochemical process.
B) It involves oxidation of food into carbon dioxide and water.
C) It takes place within the cells.
D) All of these
Answer:
D) All of these

Question 2.
In human beings, muscle cramps occur after heavy exercise. It is because
A) partial breakdown of glucose produces lactic acid.
B) complete breakdown of glucose produces lactic acid.
C) muscle cells respire in the presence of oxygen.
D) supply of oxygen to muscle cells increases.
Answer:
A) partial breakdown of glucose produces lactic acid.

Question 3.
Glucose present in our food is broken down into ………… and during cellular respiration.
A) alcohol, water
B) alcohol, carbon dioxide
C) carbon dioxide, water
D) oxygen, water
Answer:
C) carbon dioxide, water

Question 4.
In yeast, anaerobic breaking down of glucose results in the formation of
A) carbon dioxide
B) alcohol
C) oxygen
D) both (A) and (B)
Answer:
D) both (A) and (B)

Question 5.
Which of the following statements is correct ?
A) Inhaled air contains more oxygen than that of exhaled air.
B) Exhaled air contains more oxygen than that of inhaled air.
C) Inhaled air contains equal amount of carbon dioxide and oxygen.
D) Exhaled air contains equal amount of carbon dioxide and oxygen.
Answer:
A) Inhaled air contains more oxygen than that of exhaled air.

Question 6.
An adult human at rest, breathes about ………… times in a minute.
A) 18-20
B) 15-18
C) 10-15
D) 10-18
Answer:
B) 15-18

Question 7.
Breathing rate
i) remains always constant.
ii) changes according to oxygen requirement.
iii) is zero when the person is sleeping.
A) (i) and (ii)
B) (ii) and (iii)
C) Only (ii)
D) (i) and (iii)
Answer:
C) Only (ii)

Question 8.
A person’s breathing rate is faster when he/she is
A) sleeping
B) running
C) reading a book
D) walking.
Answer:
B) running

Question 9.
Select the correct statement out of the following.
A) Normally we breathe 16-18 times per minute.
B) Breathing rate increases during physical activity.
C) Breathing rate remains same under all conditions.
D) Both (A) and (B)
Answer:
D) Both (A) and (B)

Question 10.
Which of the following organs serves as the common passage for both food and air?
A) Pharynx
B) Larynx
C) Oesophagus
D) Trachea
Answer:
A) Pharynx

Question 11.
The path followed by carbon dioxide to go out of the lungs is
A) Lungs → Pharynx → Trachea → Nostrils
B) Lungs → Trachea → Pharynx → Nostrils
C) Nostrils→ Pharynx → Trachea → Lungs
D) Nostrils → Trachea → Pharynx → Lungs
Answer:
B) Lungs → Trachea → Pharynx → Nostrils

Question 12.
Select the incorrect statements.
i) We should always breathe through the nose.
ii) During breathing, movement of diaphragm and the rib cage takes place.
iii) Space in the chest cavity increases during exhalation.
iv) During exhalation, diaphragm moves down.
A) (i) and (iv)
B) Only (iii)
C) (iii) and (iv)
D) (i) and (iii)
Answer:
C) (iii) and (iv)

Question 13.
When we blow air into a glass containing lime water, it turns milky due to
A) oxygen
B) carbon dioxide
C) water vapour
D) hydrogen.
Answer:
B) carbon dioxide

Question 14.
Which of the following correctly represents the approximate composition of exhaled air by humans?
A) O₂=21 CO₂=4.4
B) O₂=21 CO₂=0.04
C) O₂=16.4 CO₂=4.4
D) O₂=16.4 CO₂=16.4
Answer:
C) O₂=16.4 CO₂=4.4

Question 15.
Spiracles are present in
A) Earthworms
B) Snakes
C) Frogs
D) Cockroaches
Answer:
D) Cockroaches

Question 16.
Frogs can breathe through their
A) Lungs
B) Spiracles
C) Skin
D) Both (A) and (C)
Answer:
D) Both (A) and (C)

Question 17.
………… in fish help them to use oxygen dissolved in water.
A) Lungs
B) Gills
C) Spiracles
D) Tracheae
Answer:
B) Gills

Question 18.
Exchange of gases takes place in the gills with the help of
A) Spiracles
B) Blood vessels
C) Tracheae
D) Muscles
Answer:
B) Blood vessels

Question 19.
Gills are the projections of the
A) Muscles
B) Scales
C) Skin
D) None of these
Answer:
C) Skin

Question 20.
Tiny pores on the leaves of plants through which exchange of gases takes place are called
A) Nostrils
B) Stomata
C) Spiracles
D) Lenticels
Answer:
B) Stomata

Question 21.
Select the correct statement regarding plant respiration.
A) Root cells of plants need oxygen to generate energy.
B) Stomata help in gaseous exchange in plants.
C) Plant roots obtain oxygen from air trapped between soil particles.
D) All of these
Answer:
D) All of these

Question 22.
Cutaneous respiration occurs in
A) Amoeba
B) earthworm
C) Paramaecium
D) Fish
Answer:
B) earthworm

Question 23.
Gills are made up of large number of
A) Alveoli
B) Spiracles
C) Filaments
D) Lenticels
Answer:
C) Filaments

Question 24.
The red coloured pigment present in blood is called (P). It combines with oxygen to form a temporary compound called (Q). Select the correct option for P and Q.
A) P- Haemoglobin, Q-Carboxyhaemoglobin
B) P-Haemoglobin, Q-Oxyhaemoglobin
C) P-RBCs, Q-Haemoglobin
D) P- RBC, Q- Carboxyhaemoglobin
Answer:
B) P-Haemoglobin, Q-Oxyhaemoglobin

Question 25.
Tiny air sacs present in the lungs are called
A) Lenticels
B) Alveoli
C) Bronchioles
D) Trachae.
Answer:
B) Alveoli

Question 26.
Which of the following statements is correct for anaerobic respiration ?
A) Food is broken down in the absence of oxygen to release energy.
B) Breakdown of food occurs in presence of oxygen.
C) It is slow process compared to aerobic respiration.
D) It produces large amount of energy compared to aerobic respiration.
Answer:
A) Food is broken down in the absence of oxygen to release energy.

Question 27.
Identify the labels (P, Q and R) in the given figure and select the correct option.

Answer:
(A)

Question 28.
Select the correct statements.
i) Inside the lungs, the windpipe divides into bronchi.
ii) Unicellular organisms do not respire as they do not posses lungs like humans.
iii) Oxygen is circulated in our body along with blood with the help of haemoglobin.
iv) Yeasts can survive without oxygen.
A) (i) and (iv)
B) (iii) and (iv)
C) (i) and (iii)
D) (i) and (ii)
Answer:
B) (iii) and (iv)

Question 29.
Select the correct matches.
i) Gills – Blood capillaries
ii) Lungs – Alveoli
iii) Leaves – Lenticels
iv) Roots – Stomata
A) (ii) and (iii)
B) (i) and (iv)
C) (i) and (ii)
D) (i), (ii) and (iii)
Answer:
C) (i) and (ii)

Question 30.
The given figure illustrates the effect of exhaled air on lime water.
Lime water turns milky due to the presence of ………… in exhaled air.

A) carbon monoxide
B) Carbon dioxide
C) nitrogen
D) oxygen
Answer:
B) Carbon dioxide

Question 31.
Study the given experimental set-up. Which of the following statements holds true regarding the rubber sheet that is pulled down?

A) Air pressure inside the bell jar decreases.
B) The two small balloons expand.
C) This is similar to the contraction of lungs during exhalation.
D) Both (A) and (B)
Answer:
D) Both (A) and (B)

Question 32.
Select the incorrect statement regarding given structures.
A) These are stomata present on leaf surfaces.
B) These structures help in gaseous exchange in plants.
C) These open and close in response to presence and absence of water.
D) These are present in roots also.
Answer:
D) These are present in roots also.

Question 33.
Given figure illustrates the internal structure of lungs. The exchange of gases takes place at which labelled structure?

A) I
B) II
C) III
D) IV
Answer:
D) IV

II. Fill in the blanks

1. The taking in of air rich in oxygen into the body is called ………… and giving out. air rich in carbon dioxide is known as …………
Answer: Inhalation, exhalation

2. Normal breathing rate of a healthy adult is ………… times/minute.
Answer: 15-18

3. The breathing rate ………… when we need more energy, i.e., while walking, running or exercising.
Answer: increases

4. ………… is a part of the process of respiration.
Answer: breathing

5. A ………… is composed of one inhalation and one exhalation.
Answer: breathe

6. ………… is a large muscular sheet that forms the floor of the chest cavity.
Answer: Diaphragm

7. ………… are the main organs of respiration present in the ………… of our body.
Answer: lungs, chest cavity

8. Smoking can damage your ………… and can cause …………
Answer: lungs, cancer

9. Breathing involves the movement of the ………… and the …………
Answer: diaphragm, ribcase

10. ………… expels the foreign particles like dust, pollens, etc.; from the inhaled air.
Answer: sneeze

11. Animals such as elephants, cows, lions, etc., have ………… for breathing.
Answer: lungs

12. ………… and ………… breathe through skin.
Answer: Earthworms, frogs

13. Insects such as ………… have small openings on the sides of their body called …………
Answer: cockroach, spiracles

14. ………… have a pair of lungs like human beings, but they can also breathe through their …………
Answer: Frogs, skin

15. Insects have a network of air tubes called ………… for exchange of gases.
Answer: tracheal tubes

16. Oxygen-rich haemoglobin is called …………
Answer: oxyhaemoglobin

17. ………… is an anaerobic process.
Answer: Fermentation

18. Increased physical activity ………… the rate of breathing.
Answer: increases

19. The products of anaerobic respiration are ………… and …………
Answer: ehtyl alcohol, carbondioxide

20. During heavy exercise, supply of ………… to the muscle cells is insufficient and hence, ………… respiration takes place in the muscle cells.
Answer: oxygen, anaerobic

21. The respiratory organs of woody and non-woody plants are ………… and ………… respectively.
Answer: lenticles, stomata

22. Gills are supplied with ………… for the exchange of gases.
Answer: blood vessels

23. Plants have root ………… that absorbs oxygen present in the air space present between the soil particles.
Answer: hair

24. Yeasts are ………… organisms which are used to make ………… and …………
Answer: single-celled, beer, wine

25. ………… is produced in the muscle cells when they respire anaerobically.
Answer: Lactic acid

III. True Or False

1. Cellular respiration takes place only in the cells of the lungs.
Answer: False

2. Yeasts breakdown glucose into lactic acid.
Answer: False

3. During heavy exercise, fast running, etc., glucose is broken down into lactic acid.
Answer: True

4. Complete breakdown of glucose takes place only in the presence of oxygen.
Answer: True

5. Inhaled air is rich in carbon dioxide.
Answer: False

6. Our muscle cells can respire anaerobically for a short time.
Answer: True

7. Yeasts are single-celled organisms.
Answer: True

8. Muscle cramps occur after heavy exercise due to the accumulation of acetic acid formed by partial breakdown of glucose.
Answer: False

9. During breathing, only diaphragm moves.
Answer: False

10. Exhalation reduces the size of the chest cavity.
Answer: True

11. Our lungs are surrounded by the diaphragm.
Answer: False

12. Our lungs expand during exhalation.
Answer: False

13. During exhalation, diaphragm moves up to its former position.
Answer: True

14. When we inhale air, it passes through our nostrils into the chest cavity.
Answer: False

15. Gills are absent in whales.
Answer: True

16. Gills are well-supplied with a network of tracheal tubes.
Answer: False

17. Fish use the dissolved oxygen present in water for breathing.
Answer: True

18. Whales and dolphins often come up to the water surface for breathing.
Answer: True

19. During breathing, the exchange of gases from the gills into the body tissues occurs through the blood vessels.
Answer: True

20. Plants carry out photosynthesis only during the day and respiration only at night.
Answer: False

Class 7 Science MCQ