Which activity can occur with out the use of energy

Passive transport involves movement of ions and other atomic or molecular substances across cell membranes without need of energy input.

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.

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.