As you can see in the table presented below, all of the gametophytes have seeds do not form in an enclosed structure and <span>undergo alternation of generations (marked in purple)
The gingkos were widespread in the distant past, but are now presented with only one species with fan-like leaves, the Gingko Biloba. (green)
The gnetophytes have three genera with very different looking species. One of the most iconic ones being the Welwitschia mirabilis often called the wise man's beard. (blue)
The conifers include redwoods, like sequoias and all, have pines as leaves and produce cones. (brown)</span>
Aristotle is the father of biology
Migration is D, the seasonal movement of organisms between locations!
Answer:
Option A, Key stone
Explanation:
A keystone species plays a major role in an ecosystem as it is the species whose presence effects all other species in the ecosystem .In general a keystone species is always a dominant predator that feed on prey population. If it is removed, the prey population will explode and the population diversity will reduce. For example - bison, prairie dog etc.
Hence, option A is correct