A dihybrid test cross is made between genes J and M. Four categories of offspring are produced: JM, Jm, jM, and jm. You wish to use the X2 test to test the hypothesis that the J and M genes are unlinked. How many degrees of freedom would there be in this test?

weathering is the answer.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

during the process of dna replication, brdu can replace thymidine and incorporate into the newly synthesized dna, cell proliferation thus can be reflected in the extent of brdu incorporation.