Several Species of Sea Urchins May Inhabit the Same Tide

Multiple Choice

Several species of sea urchins may inhabit the same tide pool and their reproductive periods overlap.Although they practice external fertilization,they seldom interbreed because eggs produce chemicals that are only attractive to sperm of their own species.This is an example of a ________ barrier that ________.

A) prezygotic; causes geographic isolation
B) prezygotic; causes temporal isolation
C) prezygotic; prevents gamete fusion
D) postzygotic; prevents zygote fusion
E) postzygotic; causes hybrid infertility