It was necessary, for life to exist on Earth, that organisms’ possess the ability to pass, store, and pass on molecular information to the next generation. The two molecules capable of these two processes are RNA and DNA. What probably accounts for the switch to DNA-based genetic systems during the evolution of life on Earth?

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.

Milk production during breastfeeding is increased by the suckling of a newborn from his mother's nipple. this type of feedback mechanism best describes a positive or negative

Describe the two types of vascular tissue