Answer:
The Sun
Explanation:
it is essential to doing photosynthesis
<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.
The *heart* is the main organ of the circulatory system.
The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The system is responsible for the flow of blood, nutrients, oxygen and other gases, and as well as hormones to and from cells.
The answer to this question is that two different neutral isotopes of
the same element will have the same atomic number. This is due to them
having the same number of protons, and it is these protons which
determine the atomic number. However, these istotopes will have
different masses due to a difference in the amount of neutrons.