When we think of respiration, we usually think of inhaling oxygen and exhaling carbon dioxide. Assuming that all of the CO2 we exhale is waste
from cellular respiration, how does the carbon atom in CO2 enter the body?
A. In a molecule of carbon dioxide
B. In a molecule of water
C. In a molecule of glucose
D. In particulate matter we inhale.

Are salt and soap nutrients or toxins for yeast? explain.

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.

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating