Which of the following is an example of a biotic factor? (2 points)
Group of answer choices
The salinity level in a salt marsh
The temperature of water at the seafloor
The shrimp population in a bay
The amount of sunlight reaching a seagrass bed

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Acceleration is a direct result of a.) balanced forces b.) unbalanced forces c.) gravity d.) velocity

Jason adds the antibiotic penicillin to a bacterial culture. the bacteria develop genetic modifications in their genome, which gives them resistance to the antibiotic penicillin. what caused this genetic modification?