Essential nutrients move through a cell membrane by both passive transport and active transport. Which of the following correctly describes the transport of materials across a cell membrane? A.) Active transport requires chemical energy to move nutrients from areas of low concentration to areas of high concentration.

B.) Passive transport requires chemical energy to move nutrients from areas of low concentration to areas of high concentration.

C.) Active transport moves nutrients from areas of high concentration to areas of low concentration without the use of chemical energy.

D.) Passive transport moves nutrients from areas of low concentration to areas of high concentration without the use of chemical energy.

A.) Active transport requires chemical energy to move nutrients from areas of low concentration to areas of high concentration.

Explanation:

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: