what is the difference between homozygous and heterozygous?

Individual organisms carrying two identical alleles (eg RR or rr) are called homologous. Whereas different organisms bear different alleles (for example Rr) is called heterozygous.

A homozygous trait occurs when two pairs of the same type form a trait. A heterozygous is a feature when two different types of alleles form a trait. In this type, the dominant and retrograde (recessive) alleles are present in the pair, and the dominant will represent the kind of progeny.

Just like humans are diploid organisms, which have two copies of each chromosome, receiving a complete set of chromosomes from their mother and a complete set from their father. These two chromosomes which correspond to each other are called homologous chromosomes. Even the locus (location) is the same as these genes in homologous chromosomes.

For example, here we are talking about hair color and consider that we have two gametes of this gene – black hair color (R) and Other allele codes for gray hair color (r). Homologous pairs of chromosomes have the same allele (both black or brown) or different alleles (black and brown).

On the groundwork of these possible outcomes, we can differentiate whether they are the same alleles, i.e. homozygous or different alleles i.e. heterozygous.

Comparison BasisHomozygousHeterozygous
DefinitionHomozygous is a genetic condition where an individual inherits the same alleles of a gene from both the parents.Heterozygous is a genetic condition where an individual inherits different alleles of a gene from both parents.
Genotype representationHomozygous genotypes are represented as “AA” for homozygous-dominant and “aa” for homozygous-recessive conditions.Heterozygous genotypes are represented by Aa genotypes. “A” represent dominant allele and “a” represent recessive allele.
PhenotypesTwo different phenotypes are expressed with dominant or recessive.The phenotype is mostly expressed due to the dominant allele.
allelesHomozygous genotypes result in a single type of alleles. either dominant or recessive.Heterozygous genotypes result in two different types of alleles. One dominant and one recessive.
TraitsHomozygous genotypes produce the same traits over different generations.Heterozygous genotypes produce different traits over different generations.
Hybrid vigorThe homozygous condition doesn’t show hybrid vigor.Heterozygous condition shows hybrid vigor.
TypesHomozygous-dominant and homozygous-recessive are two types of homozygous conditions.The heterozygous condition can be expressed in three different ways; co-dominance, incomplete dominance, and complete dominance.
Also calledOrganisms or cells with the homozygous condition are termed as homozygotes.Organisms or cells with the heterozygous condition are termed as heterozygotes.
Observed inHomozygous genotypes are observed in organism reproducing by asexual means.Heterozygous genotypes are mostly seen in organism reproducing by sexual means.
DiseasesCommon diseases associated with the homozygous condition include fibrosis, sickle cell anemia, and phenylketonuria.Common diseases associated with the heterozygous condition include Huntington’s disease, Marfan’s syndrome, and familial hypercholesterolemia.
Diffrence : Homozygouse Vs Heterozygous.

Definition Of Homogenous Alleles.

In general, humans have the same genes. A number of are varied. And these genes control our physical appearance and health.

Each variation is called an allele. Your gene consists of two inherited alleles. One comes from your biological mother and one comes from your biological father.

If the alleles are identical, that means both the gene is either recessive or a dominant gene. Then a person or organism is homozygous. For example, a person has identical alleles for the gene expression that are responsible for the cause of brown hair.

But what if your alleles are not identical, in that case, the gene has two different alleles one is called dominant allele and the other is a recessive allele. However, in homozygous condition, this interaction doesn’t occur. As I say above you either have two dominant alleles or two recessive alleles.

Example Of Homozygous

Eye Color

The brown eye color allele is dominant over the blue eye allele. You can have brown eyes whether you’re homozygous (two alleles for brown eyes) or heterozygous (one for brown and one for blue).

This is unlike the allele for blue eyes, which is recessive. You need two identical blue eye alleles in order to have blue eyes.

Heterozygous Definition

Your genes are made of DNA. This DNA provides instructions, which determines traits like your hair color and blood type.

There are different versions of genes. Each version is called an allele. For each gene, you inherit two alleles: one from your biological father and one from your biological mother. Together, these alleles are called a genotype.

If the two versions are different, you have a heterozygous genotype for that gene. For example, being heterozygous for hair color could mean you have one allele for red hair and one allele for brown hair.

The relationship between the two alleles affects which traits are expressed. It also determines what characteristics you’re a carrier for.

Examples Of Heterozygouse Condition

Eye Color (Complete Dominance)

One example is eye color, which is controlled by several genes. The allele for brown eyes is dominant to the one for blue eyes. even you have one of each, you will have brown eyes.

However, you still have the recessive allele for blue eyes. If you reproduce with someone who has the same allele, it’s possible that your child will have blue eyes.

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