B because cactus' are usually in a dry environment, they close their stomata during the day to keep water vapor from leaving the plant. Instead they do their processes at night to avoid extreme water loss.
Its either B or D. That's about all i can do. sorry
Answer:
The genetic code is degenerate.
Explanation:
The genetic code is degenerate: there are 64 triplets of different codons (sequence of three bases of mRNA that codes for a certain amino acid) and 20 amino acids. That is, an amico acid can be encoded by more than one codon.
The ostrich doesn't strictly live in one biome, while it is true that they live in a warmer, dryer climate most of the time. But they are also known to live in colder regions as well, they live a nomadic lifestyle, as long as they can find food and water they can live happily.
Hope this helps!
Answer;
-Down the concentration gradients; evenly distributed
Diffusing molecules move down the concentration gradients until they are evenly distributed.
Explanation;
Diffusion is the movement of particles from an area of higher concentration to an area of lower concentration.
-Whenever a substance exists in greater concentration on one side of a semipermeable membrane, such as cell membranes, any substance that can move down its concentration gradient across the membrane will do so. If the substances can move across the cell membrane without the cell expending energy, the movement of molecules is called passive transport.
-The mechanism of molecules moving across a cell membrane from the side where they are more concentrated to the side where they are less concentrated is a form of passive transport called simple diffusion.
