Why do most barnacles live in water with a constant temperature

The image shows embryos of three vertebrate classes

What advantages does a pedigree have over a written passage?

In order to study genetic mutations, scientists must study genetic material. which statement describes the genetic material scientists are most likely studying? a) they study alleles that contain chromosomes, which are rna. b) they study alleles that contain genes, which are chromosomes. c) they study chromosomes that contain genes, which are dna segments.