The complete period of non division during the cell cycle is G0 (Gap zero).
For the first question, the age of each strip of rock is needed to determine the rate of seafloor spreading. The answer is B.
For the second question, the answer is A.
In flowering plants the gametophyte phases are reduced to a few cells dependant for their nutrition on the Sporophyte. The gametophyte comprises the main plant, while the diploid sporophyte is much smaller and is attached to the gametophyte. Both spores and the resulting ganetophyte are haploid, which means they only have one set of chromosomes. The mature gametophyte produces male or female gametes by mitosis. The fusion of male and female gametes produces a diploid zygote which then develops into a new sporophyte.