Changes in the gene pool can occur due to various mechanisms. in 1989, a large oil spill occurred in prince william sound, alaska, when the exxon valdez oil tanker ran aground. approximately 11 million gallons of oil were spilled and spread 1,300 miles along the alaskan coastline. the damage from the oil spill affected thousands of animals in the area, including killer whales, harbor seals, sea otters, fish, and sea birds. which mechanism most likely affected the gene pools of the organism populations in the areas around the oil spill?

a.) genetic drift
b.) gene flow
c.) gene mutation
d.) genetic variation

a. Genetic drift

Explanation:

When there is a change in the allele frequencies of one or more populations due to a chance event, it is called genetic drift. It is random and mostly affects the populations of smaller sizes. In the given example, an accidental oil spill affected the gene pools of the animal populations present in the nearby regions. In this case, the gene pool was not changed by natural selection but by a chance event. Therefore, it represents an example of genetic drift.

energy and particles

step 1: nitrogen fixation- conversion of atmospheric no₂ into forms useful to plants by lightning, bacteria, and cyanobacteria.

step 2: nitrification-process of converting ammonia to nitrite or nitrate.

step 3: assimilation-plant roots absorb new form of nitrogen.

step 4: ammonification-conversion of organic nitrogen to ammonia by bacteria involved in decomposition.

step 5: denitrification-bacteria turns the decomposed matter back into n₂o, which is released into atmosphere; repeat cycle.