One parent has the sickle cell disease gene, and the other parent does not. which best describes the child’s chances of getting sickle cell disease?

impossible, because the child would have to inherit two copies of the gene
unlikely, because few children can be affected by inheriting one copy of the gene
possible, because the child would only have to inherit one copy of the gene
likely, because the child can be affected by inheriting two copies of the gene

answer:

possible because they are related

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: