In the human stomach, chemical reactions take place in an acidic environment. some of these reactions are catalyzed by enzymes. how would these enzymes most likely function in an environment where the ph was doubled?
(a)the enzymes would interfere with chemical reactions by bonding with the reactants.
(b)the enzymes would not be able to function properly outside of their optimal ph range.
(c)the rate of the reactions that are catalyzed by the enzymes would double.
(d)the rate of the reactions would increase as the ph is increased.

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:

answer; polycythemia is the correct answer;