Spermatogonia are the self-renewing, mitotic germ cells of the testis from which sperm arise by means of the differentiation pathway known as spermatogenesis 1. By contrast with hematopoietic and ...

Department of Biological Sciences, Wright State University, Dayton, USA. Reproductive isolation refers collectively to all genetic mechanisms that prevent or limit gene flow between populations [1].

In fig.2, the young participants chose the hazel leaf, a tree that produces unisexual flowers, with male and female flowers found on the same tree but in separate clusters. These flowers rely on the ...