White blood cells (D) aid in the immune system to fight infections.
Answer:
Humoral immunity:
Humoral immunity is mediated by the macromolecules present in the extracellular fluid. This immunity provides protection against the pathogens present in the extracellular fluid. B- cells are mainly produced by the humoral immunity. The plasma cell and memory cells are generated in the human body. Antibodies kill the pathogens in humoral immunity.
Cell mediated immunity:
Cell mediated immunity is activated by the infected cells. This immunity provides protection against intracellular pathogens. T- cells are mainly produced by cell mediated immunity. T helper cells and T killer cells are mainly produced in the cell mediated immunity. Cytokines kill the pathogens in case of cell mediated immunity.
A food chain shows how energy flows from one organism to another. In general, energy flows from the Sun to producers and then to consumers. The path is linear as the energy present in one step is transferred to the next. You can find specific examples of this pathway in an ecosystem.
Answer:
dd, both parents would also be (dd) as well.
Explanation:
It would be the first one. Hope this helps :)