Most organisms need oxygen for a single purpose. what is that purpose?

Q1.8. continuing your studies, you perform a transplant experiment. you chisel up multiple rocks from the upper intertidal zone, each holding 10 individuals of species a, and move them to the lower intertidal zone among individuals of species c. you count the number of individuals of all species on the rocks every day for 30 days. based on your findings, what can you conclude? (remember that all 3 species settle in this zone at equal rates.)

What adaptation is apparent in the bodies of the three tortoise species shown in figure 16-2

Which of the following is the main purpose of a human community?