Which of the following is true
(1)Gills are used by most of the aquatic animals

(2)lungs are used by most of the terrestrial animals

(3)Mammals have a well developed respiratory system

(4)All of the above

How many external nostrils are present in human beings
1. 1
2. 2
3. 3
4. None of these

The mechanism of breathing depends on animal’s
1. habitat
2. level of organisation
3. Both A and B
4. Body segmentation

Frogs respire through
1. Skin
2. lungs
3. buccal cavity
4. All of these

Assertion       :       Severe Acute Respiratory Syndrome (SARS) originated in China.

Reason          :       China is the most populated country of the world

1. Both Assertion (A) and Reason (R) are the true and Reason (R) is a correct explanation of Assertion (A).

 2.Both Assertion (A) and Reason (R) are the true but Reason (R) is not a correct explanation of Assertion (A).

3.Assertion (A) is true and Reason (R) is false.

4. Assertion (A) is false and Reason (R) is true

Respiratory organ of scorpion is
(1)Book-lungs

(2)Book-gills

(3)Buccal cavity

(4)Lungs

Which of the following is incorrect
(1)Whale-Lungs

(2)Tadepole larva-Gills

(3)Earthworm-moist skin

(4)Spider-lungs

How many of the following invertebrates exchange O₂ with CO₂ by simple diffusion
(Sponges, Coelenterates, flatworms, Annelida, Arthropoda, Mollusca, Pisces,)
1. 6
2. 5
3. 4
4. 3

Nasopharynx opens through_________ of the larynx region into the trachea.
1. glottis
2. gullet
3. epiglottis
4. All of these