PLEASE HELP! Scientists performed studies on mussels and clams. They placed these different species in fresh water that had contaminants commonly found in agricultural runoff and human and animal waste. Within a few days, the mussels and clams had removed the majority of the contaminants. How do these findings relate to ecosystem services in natural environments? A.
Introducing new species of mussels and clams will help reduce erosion and runoff into rivers.

B.
Increasing the biodiversity of mussels and clams in freshwater ecosystems will improve water quality.

C.
Growing mussels and clams in rivers will provide humans with a steady source of food.

D.
Using a single species of mussel or clam will remove greenhouse gasses from the atmosphere.

Examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. examine the two squirrel populations in the accompanying figure. the populations are separated by a geographic barrier. if after a long period of time the two species are no longer separated, what evidence is needed to determine if speciation has occurred? the figure shows two populations of squirrels separated by a geographic barrier. polyploidy is creating new species. the two populations are not interbreeding freely. hybrid offspring of the two populations begin to appear. one species will increase into a population size twice as large as the other species.

Many farmers prefer cattle without horns because it is safer for their herds. the allele for no horns (n) is dominant to the allele for the presence of horns (n). a farmer mates a male with horns to a heterozygous female without horns. what is the chance that the offspring will have horns?

Select the correct answer. which mutation is harmful to the organism? a. a mutation allowing moths to camouflage better on blackened tree bark b. a mutation making staphylococcus aureus resistant to the antibiotic methicillin c. a mutation inhibiting human immunodeficiency virus from attaching to and entering the cell d. a mutation causing uncontrolled cell division e. a mutation giving plant leaves a bitter taste to discourage herbivores from eating them