Arecessive trait will be observed in individuals that are for that trait.
heterozygous
homozygous or heterozygous
homozygous
diploid

Homozygous

Explanation:

Mendel is known as the father of genetics. The concept of dominance and recessive trait was explained by Mendel while working on the pea plant Pisum sativum.

The individual has two alleles for a particular trait. The dominant trait is expressed in the individual in homozygous dominant and in heterozygous condition as well. The recessive trait is only observed in case of homozygous recessive condition. The dominant trait hides the expression of recessive trait in heterozygous condition.

Thus, the correct answer is option (3).

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: