First thing is Male gametes are called sperm and Female gametes are called eggs. So some physical differences are that the eggs are spherical in shape, much larger then sperm, and are immobile (they stay in the female reproductive organ during fertilization). Sperm are smaller, are in a cone shape, and have tails so the could move to the egg during fertilization.
Answer:
The relationship between frogs and fishes in a pod is predation.
For giving you understanding ; we need Free O2 but Oxygen is also available in H20 right why dont we use it !!
As the early atmosphere was reducing as there was no free oxygen but it was later produced by chemoautotrophic bacteria !! Living thing release O2 in atmosphere thus making it oxidising in nature and then life evolves !!
