Dominant alleles is the answer!
The best answer is Hormone.
Hormones are chemicals secreted by one tissue and affect the functioning of other tissues and cells.
Hormones are secreted by glands of the endocrine system. They are secreted into the blood and also extracellular fluid. They then circulate in the blood and come into contact with essential all cells, but a specific hormone will only affect a limited number of cells, namely the cells that bear a receptor for that hormone.
Red blood cells for example have receptors for the insulin hormone that is produced by the pancreas. They will therefore be directly affected by insulin while all other cells in the blood remain oblivious of this hormone..
Heterozygous is a term used in genetics to describe when two variations of a gene (known as alleles) are paired at the same location (locus) on a chromosome. By contrast, homozygous is when there are two copies of the same allele at the same locus.
The term heterozygous is derived from "hetero-" meaning different and "-zygous" meaning related to a fertilized egg (zygote).
Determining Traits
Humans are called diploid organisms because they have two alleles at each locus, with one allele inherited from each parent. The specific pairing of alleles translates to variations in an individual’s genetic traits.
An allele can either be dominant or recessive. Dominant alleles are those that express a trait even if there is only one copy. Recessive alleles can only express themselves if there are two copies.
One such example is brown eyes (which is dominant) and blue eyes (which is recessive). If the alleles are heterozygous, the dominant allele would express itself over the recessive allele, resulting in brown eyes. At the same time, the person would be considered a "carrier" of the recessive allele, meaning that the blue eye allele could be passed to offspring even if that person has brown eyes.
Alleles can also be incompletely dominant, an intermediate form of inheritance where neither
Decrease
Explanation : if there is less born and a greater number dead then math will tell you that the population would decrease have a nice day (:
