If oxygen atoms are in low concentration outside of a cell, but the cell requires more oxygen, how will the cell move the oxygen inside the membrane?
a. diffusion
b. osmosis
c. active transport

Which event would lead to primary succession of a forest?

What should be the strand of complementary dna produced by the strand of dna shown below cgt ata

12) several teeth were found in an area of flat land covered with trees and plants. the teeth were examined by a paleontologist, and it was determined that the teeth came from a shark. they found many other shark teeth in this area. however, the people who discovered the teeth were puzzled, because there was no source of water near where the fossils were found. what is the paleontologist's best explanation for why the teeth were found in this area? a) sharks used to live on flat land. b) this area was once covered with salt water. c) this area was once covered with freshwater. d) someone buried the shark teeth deep in the ground.