Which statement explains why athletes experience a burning sensation in their muscles after vigorous exercise?
A. Their muscles have taken in too much oxygen.
B. The conditions in their muscles have become anaerobic.
C. The temperature in their muscles has become too high.
D. Their muscles have become flooded with glucose.

B

Explanation:

Athletes get a burning sensation due to a LACK of oxygen in their muscles. And the definition of absence of oxygen is anaerobic.

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation:

the answer will be a) proteins i believe