<u>Answer</u>: C) Directional selection occurs when one of two extreme phenotypes is selected for.
The type of natural selection known as directional selection is defined in population genetics in the case in which an extreme phenotype is favored over other phenotype. Thus, the population and its allele frequency will evolve towards this end of the trait spectrum (extreme phenotype). This is also the case illustrated in the graph where the right side represents the extreme phenotype.
Answer:
Explanation:
1) Excitation brings about contraction.
2) Contraction leads to an increase in blood pressure.
3) Changes in blood pressure results in the opening and closing of the heart valves.
4) The opening and closing of heart valves then regulates the flow of blood and it's volume.
Answer:
Inter-Tidal Zone
Explanation:
This area is known as the inter-tidal zone, where the animals must be able to withstand the sun's heat and the ocean.
Answer:
spherical (coccus), rodlike (bacillus), or curved (vibrio, spirillum, or spirochete).