Proton pumps are used in various ways by members of every domain of organisms: bacteria, archaea, and eukarya. according to evolution theory, what does this most probably mean?

The right answer is B. They were used by the common ancestor of all three domains of life.

The proton pump is a transmembrane protein, and more specifically an active membrane transporter, which displaces protons against their concentration gradient using the energy released by the hydrolysis of an adenosine triphosphate (ATP) molecule. Its operation results in the enrichment of a cell compartment (lysosome) or a vesicle (acetylcholine vesicle) in H + ions (ie a proton alone), that is to say to a decrease of the pH in these vesicles or acidification.

Answer;

-Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

Explanation;

-The proton gradient generated by proton pumping during the electron transport chain is a stored form of energy. When protons flow back down their concentration gradient (from the intermembrane space to the matrix), their only route is through ATP synthase, an enzyme embedded in the inner mitochondrial membrane.

-Proton pumps are used in various ways by members of every domain of organisms: bacteria, archaea, and eukarya, which means that proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

hey bro i looked it up on google the structure of the eye-spot in euglena viridie, e. ehrenbergii, and phacus pyriyorme is not as franzé haa described it. the so-called “crystal body” and “lens bodies” were not found in any of the individuals of the species examined by me. as earlier observers have stated, the eye-spot consists simply of a mass of pigment granules arranged in a single layer, and probably embedded in a protoplasmic framework, but the latter could not be seen, and its presence was only inferred from the fact that the pigment granules must be held together in some way, thd the eye-spot as a whole is capable of expansion, and that the pigment granules can be separated from each other.

hope this   and an i get brainlsiest

a scenario where a cell may be needed to perform a form of endocytosis is when transporting large molecules. a scenario where a cell may be needed to perform a form of exocytosis is when releasing the large molecule from the cell.