AP BIOLOGY

PLANTS

TRANSPORT IN PLANTS

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Which statement explains why transpiration occurs?
A
Carbon dioxide can enter a leaf only if the stomata are open, so water vapour diffuses out and is lost.
B
Photosynthesis only uses water produced by respiration, so all the water supplied by the roots is lost through the stomata.
C
So that the plant can transport amino acids.
D
So that water produced from respiration can be excreted.
Explanation: 

Detailed explanation-1: -Through the same stomata opening carbon dioxide diffuses into the plant during photosynthesis. The reason for the above statement is both processes cannot happen simultaneously. Hence the correct answer is option A. Water vapor comes out from the planet leaf through the stomata opening.

Detailed explanation-2: -To control water loss from the leaf, gas exchange occurs through pores in the leaf surface, stomata, which are able to rapidly change their aperture. Once inside the leaf, CO, has to diffuse from the intercel-lular air spaces to the sites of carboxylation in the chloro-plast (for C, species) (Fig.

Detailed explanation-3: -Through photosynthesis, they use sunlight and carbon dioxide to make food, belching out the oxygen that we breathe as a byproduct. This evolutionary innovation is so central to plant identity that nearly all land plants use the same pores-called stomata-to take in carbon dioxide and release oxygen.

Detailed explanation-4: -Transpiration occurs because plants take in more water than they actually need at a given time. It is a way of getting rid of excess water. When water is removed from the plant, it can more easily access the carbon dioxide that it needs for photosynthesis.

Detailed explanation-5: -It occurs mainly through the stomata in the leaves. Besides the loss of water vapour in transpiration, exchange of oxygen and carbon dioxide in the leaf also occurs through pores called stomata. Normally stomata remain open during the day and close at night.

There is 1 question to complete.