Which of the following statements is true?

a.

the nitrogen cycle is the most important cycle for life.

b.

the oxygen cycle is the least important cycle for life.

c.

life can be sustained without any of the cycles for life present.

d.

all cycles of matter are equally important for life to be sustained

What is the difference between bacterial infections and viral infections?

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.

Explain why the plants cortex would serve as the best food source for animals