How does the exercise increase the heart beat and breathing rate?
a) muscles require more energy
b) muscles require more food
c) muscles require more oxygen
d) all of these
Exercise:
A team of climbers was climbing a high mountain. When they reached near top they feel difficulty in breathing because at high altitude there is……….
a) more oxygen
b) less oxygen
c) more carbon dioxide
d) low temperature
The exchange of substances between blood and body cell can take place at the………
a) capillaries
b) veins
c) arteries
d) heart
A person affected with anaemia looks pale and feel tired. All his body cells are getting……..
a) less food
b) less oxygen
c) less carbon dioxide
d) less water
The exchange of gases between blood and air takes place at…….
a) trachea
b) bronchi
c) bronchioles
d) alveoli
