Chemosensitive area of respiratory centre medulla is affected by

1. less CO₂ and H⁺ ions

2. less O₂ and H⁺ ions

3. excess CO₂ and H⁺ ions

4. excess O₂ and H⁺ ions.

Oxygen binding to haemoglobin in blood is

1. directly proportional to the concentration of CO₂ in the medium

2. inversely proportional to the concentration of CO₂ in the medium

3. directly proportional to the concentration of CO in the medium

4. independent of the concentration of CO in the medium.

Respiration is controlled by

1. medulla oblongata

2. cerebellum

3. hypothalamus

4. cerebrum

Which of the following match is correct?

1. Emphysema : reduction of surface area of alveoli and bronchi

2. Pneumonia : occupational disease with asbestos

3. Silicosis : inflammation of alveoli

4. Asthma : excessive secretion of bronchial mucus

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

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

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