Navy blue. For other uses, see Navy blue (disambiguation). Navy blue is a very dark shade of the color blue. French sailor in dark blue uniform. Navy blue got its name from the dark blue (contrasted with white) worn by officers in the British Royal Navy since 1748 and subsequently adopted by other navies around the world.
Hybrid sterility is what results when individuals from two. different species are able to mate but their offspring is infertile, meaning that their. offspring are not able to reproduce. Because this occurs after the formation of the. zygote, this is a postzygotic isolating mechanism, not a prezygotic mechanism.
Postzygotic isolating mechanisms are mechanisms that occur. after the formation of the zygote but prevent viable embryos or, if hybrids are. born, prevent the viability or the reproductive abilities of the hybrid. The correct answer is bâ. C. Answer c is incorrect. Temporal isolating mechanisms are prezygotic mechanisms.