What often develops into the backbone of amphibians?

What terms describes being out of water after being submerged

Cattle with brown fur and cattle with white fur will produce a reddish roan calf . when examined closely, the calf show about an even number of brown hairs and white hairs that give a reddish appearance when viewed from far away. the fact that both the brown fur allele and the white fur allele are expressed equally in the offspring is an example of

The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million