Since phytoplankton are “weak swimmers”, how do they stay near the surface for photosynthesis?

rocks and weathering-matching

yes it is weird but true

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: