Fill in the blank. the of animals is based on scientists' current understanding of the evolutionary history of living species. although they are radially symmetrical, echinoderms are more closely related to a human than to a jellyfish because they are

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: