Explanation:
To swim, they move their tails up and down, rather than back and forth as fishes do. This is because whales evolved from walking land mammals whose backbones did not naturally bend side to side, but up and down. ... Whales do the same thing as they swim, showing their ancient terrestrial heritage.
Cetaceans are fully aquatic marine mammals belonging to the order Artiodactyla, and branched off from other artiodactyls around 50 mya (million years ago). Cetaceans are thought to have evolved during the Eocene or earlier, sharing a closest common ancestor with hippopotamuses.
This is false for a number of reasons. While LH (which stands for Leutinizing Hormone) is released by the anterior pituitary gland and can be present in both females and males, it play a more predominant role in females. Working closely with FSH (Follicle Stimulating Hormone) a surge in LH begins the process of ovulation and the development of the Corpeus Leuteum.
In Males it is used both for the production of sperm but to stimulate the production of testosterone.
Answer:
The bottom one shows how the circulatory system of a fish functions.
Well, the leaves contain stomates, which let in CO2 and release O2. The roots collect water, which travel up the xylem, which are contained in the stem.
