I think the correct answer from the choices listed above is option A. Directional selection can be distinguished from disruptive selection by the elimination of extreme variations of traits. Directional selection is a natural selection where an extreme phenotype is favored than others.
In geometry the base is the side or face of a geometric figure to which an altitude is drawn,
Perhaps the answer your looking for is, a tumor suppressor gene.
Answer:
There are many green house gases and carbondioxide is one of them. Green house gas has the ability to stop the heat from going to the atmosphere. This heat energy reduces the atmospheric carbondioxide to dissolve in the ocean water so more concentration of carbondioxide is present in the atmosphere which stop the reflected sunlight rays into the space and thus increase the temperature of the earth surface. This increase in temperature called global warming.
Answer:
Direct observation of evolutionary change: creation of drug-resistant bacteria.
Fossil record: discovery of transitional forms of animals, discovery of shells of extinct organisms
Homology: similarities in mammalian forelimbs, identical genetic code in fireflies and tobacco plants, vestigial pelvis in right whales
Biogeography: resemblance of endangered island species to neighboring mainland species,