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

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

Respiratory organ of scorpion is
(1)Book-lungs

(2)Book-gills

(3)Buccal cavity

(4)Lungs

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

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

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

(2)Tadepole larva-Gills

(3)Earthworm-moist skin

(4)Spider-lungs

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

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

Which of the following is true about epiglottis
1. thin elastic cartilaginous flap
2. prevent food entry into larynx
3. Coughing occurs due to its improper movement
4. All of these

The common passage for food and air is
1. nasal passage
2. nasopharynx
3. oropharynx
4. pharynx