Answer:
Among vertebrates, external fertilization is most common in amphibians and fish. Invertebrates utilizing external fertilization are mostly benthic, sessile, or both, including animals such as coral, sea anemones, and tube-dwelling polychaetes. Benthic marine plants also use external fertilization to reproduce.
= Fish
Explanation:
Cells of same type group together to form tissue.
Tundra plants, blueberries, and birch.
<span>About 50%
Both the mother and father contribute about the same amount of genetic material to their offspring, but it's not quite 50/50. Taking humans as an example, both parents contribute the same amount of genetic material for 22 of the 23 chromosome pairs, but the 23rd pair that determines gender (the X and Y chromosomes) are of different size. So for female children, both parents contribute about the same amount, but for male children, the mother contributes a larger portion since the X chromosome is quite a bit larger than the Y chromosome from the father. Another area in which the contribution differs is the mitochondrial DNA which is contributed solely by the mother. For mammals, this is about 1% of the total genetic material.</span>
Answer:
DNA or protein can be used as a ''molecular clock'' that tells how long it has been since two species have diverged from a common ancestor. The fossil record is usually derived from sedimentary rocks laid down millions of years ago.
