What is the relationship between auxin and phototropism?

It functions as hormones or chemical messengers.

Explanation:

This shows that somehow one-sided lighting causes less plant tissue to gather on the illuminated side and more to gather on the shaded side. This makes the cells on the shaded side grow and enlarge faster, causing the sprout to bend towards the light.

option a is correct i.e.

explanation:

in context to the membrane of nerve impulse, the outer membrane of neuron is semi permeable that is only sodium ions can pass through the membrane i.e. smaller ions can pass through the membrane while larger ions cannot pass through it.

it cools slower in the earth meaning the crystals have more time to form than lava on the surface