Photosynthesis moves carbon atoms from the atmosphere to the biosphere
Is this the fast or slow carbon cycle ?

The fast carbon cycle is largely the movement of carbon through life forms on Earth, or the biosphere. During photosynthesis, plants absorb carbon dioxide and sunlight to create fuel—glucose and other sugars—for building plant structures. This process forms the foundation of the fast (biological) carbon cycle.

the offspring would all be white. if the parents are both white flowers then they have the genotype rr, which when crossed results in an all white punnet square.