When environmental conditions are unfavorable, why is it an advantage for green algae to reproduce sexually?
a. they are multicellular when conditions are unfavorable, which favors sexual reproduction.
b. sexual reproduction produces larger numbers of offspring in less time.
c. sexual reproduction produces offspring that have greater genetic variety and durable zygotes that can green algae species survive unfavorable conditions.
d. sexual reproduction produces multicellular algae instead of unicellular algae. multicellular algae are better able to survive harsh conditions.

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: