中3biology`關於stomata既問題=)20分`thz

(1)

by the opening and closure of the guard cell

detecting the intensity of light






(2i)

stomata are mostly distributed on the lower epidermis to reduce water loss

Dicotyledons usually have more stomata on the lower epidermis than the upper epidermis.

As these leaves are held horizontally, upper epidermis is directly illuminated.

Locating fewer stomata on the upper epidermis can then prevent excess water loss.

(2ii)

If the plant has floating leaves,

there will be no stomata on the lower epidermis and they absorb gases directly from water through the cuticle

(2iii)

If it is a submerged leaf, no stomata will be present on either side.

it need not to have, beacuse it is totally immersed in water

closure of stomata is not required(it doesn't have to reduce water loss)






(3)

if the the concentration of CO2 is high, more stoma is opened to absorb more CO2 for photosynthesis in daytime

Therefore, plants cannot gain carbon dioxide without simultaneously losing water vapor.






(4)

there is a layer of cuticle on the upper epidermis

stomata is mostly distributed on the lower epidermis