Groundwater flows through a layer of subsurface material called an aquifer. An aquifer would MOST LIKELY be made up of which types of material A) Gravel and sand
B) Clay and silt
C) Granite and basalt
D) Marble and schist

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:

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.

some inherited genetic mutations can be good for the offspring, so the answer is different genetic mutations cause many forms of cancer.