Answer:
Explanation:
Although protons resemble other positive ions such as Na+ and K+ in their movement across membranes, in some respects they are unique. Hydrogen atoms are by far the most abundant type of atom in living organisms; they are plentiful not only in all carbon-containing biological molecules, but also in the water molecules that surround them. The protons in water are highly mobile, flickering through the hydrogen-bonded network of water molecules by rapidly dissociating from one water molecule to associate with its neighbor, Protons are thought to move across a protein pump embedded in a lipid bilayer in a similar way: they transfer from one amino acid side chain to another, following a special channel through the protein.
C can be taken out of the question as eukaryotic cells do not have a nucleus. A lysosome is is only in prokaryotic cells so B can be taken out of the question. The answer should be D.
Answer:
So more people can be like us
Explanation:
Answer: We have found fossils that share specific bony traits that are found only in all whales but absent in every other mammal group, indicating descent from a shared common ancestor with modern whales, and these fossils had legs fully adapted for walking on land, and fundamentally identical to those of older mammals that precede the shared common ancestor that these mammals share with whales.
This tells us that the shared common ancestor of whales and these mammals with legs almost certainly had legs themselves, and inherited those legs from their own older mammal ancestors.
Therefore, whales have ancestors in their lineage that walked on land with legs.
(We also have multiple fossils of ancient whales that had legs transitional in form between fully terrestrial walking legs and flippers adapted for swimming, and modern whales still possess a remnant hip bone buried deep in their bodies.)
Answer:
Earth's creatures are on the brink of a sixth mass extinction, comparable to the one that wiped out the dinosaurs. That's the conclusion of a new study, which calculates that three-quarters of today's animal species could vanish within 300 years.
Explanation:
