If a zebra migrates to join a different herd of zebras is that mutation gene flow genetic drift or natural selection?

The correct answer would be gene flow.

Explanation:

Gene flow  is explained as the transfer of genes from one population to another so there is an increase in their frequency of genes.

It is also called migration. The addition or loss of people can affect the frequencies of the gene pool even if no other evolutionary mechanisms working at the time.

Thus, the correct answer would be gene flow.

b. the carbon cycle ensures living things have a source of hydrogen

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.