The epidermis of the skin consists of many layers of tightly packed cells. the outermost layer of cells are dead. which best describes why this occurs?

a. chemical compounds containing digestive enzymes are located on the outside of the skin, and they destroy the cells.
b. blood vessels are not located in the epidermis, but in the underlying dermal connective tissue.
c. the outer layer of skin is nervous tissue and nervous tissue will not regenerate.
d. pathogens on the skin secrete toxins that affect the cellular structure, thus destroying the cell.

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

What do all macromolecules have in common with each other? oa. they all are formed from the same elements.ob. they all have major roles in cell membranesoc. they all act as catalysts in the body.od. they all have peptide bonds between carbon atoms.

The activity of the modern sample is 1.10 bq . how long does that measurement take?