They are releasing energy from organic molecules through aerobic respiration. In cell respiration, you are releasing energy, and in this case you are releasing energy from organic molecules. Because they are a single-celled organism using oxygen and releasing carbon, the process being used is aerobic respiration.
Answer:
Changes in the environment affect the food sources available for birds. For example, if a flood was to occur, there would be an abundance of fish to birds to eat. So birds with bigger beaks will be able to eat fish, to live and reproduce offspring with bigger beaks. While birds with smaller beaks will not be able to catch fish to eat, therefore decreasing the population of birds with smaller beaks.
D) Plants below the surface receive less sunlight than those on the surface
Can you please attach a link or something?
I might be able to help you then.