Answer:
C.
Explanation:
In an ecosystem you have all the factors that contribute to a population of a variety of organisms. You have wind, water or sun as some abiotic factors which in turn help plants and trees survive with sustain different species.
Natural selection is the process by which an organism uses its traits to survive and reproduce. In this mechanism of evolution, organisms have favorable traits for survival and reproduction. The more adapted an organism is to its environment, the more likely it is to have heritable traits that are passed down to new coming offsprings, and really, this also applies for the likeliness of the organism to survive and reproduce in general. The more these heritable traits are passed down and used with offspring, the more common the favorable traits are in the community.
The immune system monitor continuously the lymphocyte cell levels in order to ensure the protection of the body. These cells are a type of white blood cells that are important in determining the specificity of the response of the body to foreign substances and infectious microorganisms. This group of cells include the T cells, B cells and the natural killer cells. These are produced in the bone marrow and are transported to the lymphatic systems like the thymus, spleen and the lymph nodes. The NK cells function in cytotoxic innate immunity or the cell-mediated ones. T-cells would function by connecting to virus antigens on the outside of a cell that is infected while B-cells would connect to the virus directly in its surface.
The functional unit of the kidney is nephron. Kidney comprises two kinds of nephrons, each situated in distinct sections of the renal cortex, that is, juxtamedullary nephrons and cortical nephrons. A nephron constitutes of a renal tubule, renal corpuscle, and the associated network of capillaries. The nephron is accountable for eradicating waste from the body.
The functional unit of lungs is alveoli. They resemble a cluster of grapes, they are thin and possess moist walls. They are a single layer of cells enveloped by a layer of capillaries. The main function of the lungs is respiration. The alveoli help one to breathe, by conducting the process of gas exchange.
