Which statement best compares pioneer species with climax communities? A. Both are involved with stages of succession, but climax communities are the beginning and pioneer species are the end result.
B. Both are involved with stages of succession, but pioneer species are the beginning and climax communities are the end result.
C. The appearance of each indicates that the number of species in the area is increasing.
D. The appearance of each indicates that the number of species in the area is decreasing.

in the year 2850, humans successfully colonized mars. the martian modules that were constructed could hold only a small population of people. it is now a century later, and the population on mars has grown to 600 people. of the current mars population, 45 people express the recessive phenotype for phenylketon- uria (pku) syndrome (pp genotype).

explanation:

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.