The correct answer is A. Permian.
Explanation
The synapsids were terrestrial vertebrate mammals or animals related to them rather than to reptiles or birds that lived during the Permian (a period that began about 299 million years ago and ended about 251 million years ago) and were the dominant terrestrial vertebrates during it. These animals survived until the Triassic; however, due to the Permian-Triassic extinction, they were not the predominant vertebrate as in the previous period. Later, during the Cretatic and Jurassic periods, their development was minimal and did not have great importance as reptiles were dominant in this period. So, the correct answer is A. Permian.
Answer:
chromosome number is the precise number of chromosomes for a certain species.
Explanation:
in humans there are 46 pairs of chromosomes .
23 from father and 23 from mother.
Answer:
spleen: A ductless vascular gland that destroys old red blood cells, removes debris from the bloodstream, acts as a reservoir of blood, and produces lymphocytes
Explanation:
The correct answer is the immune system, more specifically, the thymus gland. The thymus gland, while it produces hormones like thymosin, it is more closely related to the immune system rather than the endocrine system. This is because lymphocytes that go into the thymus gland mature into T lymphocytes that can either be a helper T cell or a cytotoxic T cell, depending on the stimulus.
I'm totally sure that the next step is A)Gametophyte. As it's the most suitable from given above.
