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.
thin walls.
a moist inner surface.
a huge combined surface area.
Answer:
The citric acid cycle is fundamental to produce the energy needed for aerobic cell metabolism, thereby mutations in the enzymes involved in this metabolic pathway would be lethal to the individual
Explanation:
In aerobic organisms, the citric acid cycle (also known as the Krebs cycle), is a key metabolic pathway used to remove electrons and uses them in the electron transport chain in order to generate adenosine triphosphate (ATP), the energy currency of the cell. The citric acid cycle depends on eight enzymes that oxidize acetyl-CoA into two molecules each of carbon dioxide (CO2) and water (H2O). Thus, the citric acid cycle is a series of chemical reactions that are key to breakdown carbohydrates, fats and proteins into CO2 and H2O in order to produce energy (ATP).
i think the answer is D) but you should get someone else to confirm this.
