Question

HYPOTHETICALLY:

a) When a leaf disks are placed in the darl, they are still undergoing cellular respiration and they sink. While celular respiration consumes oxygen gas, it also produces carbon dioxide gas. Why do the leaf disk sink if the same molecules of gas are consumed and produced? Why do the leafs sink and what product of photosybthesis caused this?

b) Theoretically, if you placed a plant in a sealed container and provided a light source, it could life out its natural life to no ill effect. How?

c) After you turn off the light the leaf disk should have sunk, why?

Answer 1

(a)There was no gas left in the leaf disks beacuse cellular respiration was occuring.The oxygen generated by photosynthesis(which caused the disks to rise)is being consumed so consequently,began to sink.

(b)plants need sunlight,carbon dioxide and water for photosynthesis.In the sealed container plant it getting light,producing carbon dioxide through respiration and in a sealed container the water vapour produced by transpiration in the plants will not be able to escape.So,all the requirements for photosynthesis are fulfilled leading to plant's normal life.

(C)The sinking of leaf disc was caused by loss of gas due to respiration and plants respire irrespective of presence or absence of light.So,leaf disc should have sunk in dark also.