I believe that the answer you're looking for is Water.
Answer:
Analogous structures
Explanation:
These structures are similar but not derived from the common ancestor like homologous structures. Analogous structures are formed as a result of convergent evolution-type of evolution in which organisms develop on similar way but independently. An example of analogous structures are wings. Birds, insects and bats all have wings, with the same purpose (flight) but they evolved in their own way.
T cells. When HIV arrives in the lymph nodes – around 24 to 48 hours after exposure – they activate other immune cells, such as CD4 t-cells, HIV's primary target.
Answer;
A. leaf to mouse
Explanation;
-Considering the fact that the amount of energy at each trophic level reduces as it moves through an ecosystem from the lowest trophic level which happens to be producers (plants). And about 10 percent of this energy at any trophic level is transferred to the next level since the rest is lost largely through metabolic processes as heat.
-It means that the lower the trophic level the higher the energy obtained, for instance from producers to primary consumers, more energy is passed since it is the first passage of energy.