A seedling is a young plant sporophyte creating out of a plant incipient organism from a seed. Seedling improvement begins with germination of the seed. A common youthful seedling comprises of three fundamental parts: the radicle, the hypocotyl, and the cotyledons.
B - They both use protein channels (I think so at least) they differ because active transports use a pump to leave the cell and it uses atp (cell energy).
I'm almost sure your answer is going to be "Because the sun's mass creates a gravitational force that pulls earth towards it."
correct me if I am wrong.