Higher animals and plants most likely have
isogametes
anisogametes
oogametes

oogamates

oogamates is known to be a large non- motile gametes that contain a reserve material which is being used by the developing zygote that is formed when the sperm fuses with such gametes. Thus, gametes can be defined as a set of dissimilar chromosomes formed through mitosis.

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.