Answer:
Consider substances that can easily diffuse through the lipid bilayer of the cell membrane, such as the gases oxygen (O2) and CO2. O2 generally diffuses into cells because it is more concentrated outside of them, and CO2 typically diffuses out of cells because it is more concentrated inside of them.
Answer:
Mitochondrial proteins enter the organelle through channels formed by membrane proteins present in its inner and outer membranes.
Explanation:
All the biological membranes have lipid bilayer with the non-polar core that does not allow entry of charged and large substances. Mitochondrial proteins are synthesized in the cytosol and the unfolded proteins bind to the chaperons that deliver them to the receptors present in the outer mitochondrial membrane.
The receptor moves the protein to the membrane channels formed by integral membrane proteins of inner and outer mitochondrial membranes. The proteins enter the intermembrane space and are targeted to the inner membrane through channels while chaperons are left outside only.
The answer is D, for when one tropic level is eaten by the tropic level above it, the tropic level is supporting the higher one. I. E. Rabbits are supported by the grass because rabbits eat the grass. Also, the grass population would be larger than rabbits, the rabbits larger than snakes, so on and so forth, so B is ruled out. B states that each population is larger than the one BEFORE it, but there is no way there would be more rabbits than grass. Also, there are both herbivores and carnivores in the food chain, so A and C are out. The best answer is D.
