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Difference between homozygotes and heterozygotes

Individual organisms carrying two identical alleles (e.g. RR or rr) are called homozygotes . While individual organisms carry different alleles (e.g. Rr) they are called heterozygous .

A homozygous trait when the same type of two alleles it associates to form a stroke. A heterozygote a trait when different kinds of two alleles associate to form a stroke. In this type, alleles are present in the pair dominant and regressive, and the dominant will represent the type of trait that the offspring will show.

Since humans are diploid organisms, containing two copies of each chromosome, which inherit a complete set of chromosomes from the mother and a complete set from the father. These two matching chromosomes are called homologous chromosomes. Even the locus (location) the same as these genes in the homologous chromosomes.

Eg, here we are talking about hair color and consider that we have two alleles for this gene: one allele code for black hair color (R) and the other allele codes for brown hair color (r).

Homologous pairs of chromosomes are made up of the same alleles (both black and brown) or different alleles (black and brown). Based on these possible outcomes, we can differentiate whether they are the same alleles, ie homozygous or different alleles, ie heterozygous.

Comparison chart

Basis for homozygote heterozygote comparison
Sense If diploid organisms carry two copies of each gene, they can be identical so-called homozygous alleles. But if diploid organisms carry two copies of each gene, which can be different alleles (dominant and regressive), it can be said as heterozygous.
Results in Bring similar individuals, it means that pure for a stretch and generates true. For example, RR, rr Bring different individuals, which means that a rarely pure heterozygous individual and produce offspring with different genotype. For example Rr
Door The homozygote carries similar alleles of a trait. For example RR, rr. The heterozygote carries a different allele, e.g. Rr.
Type of alleles The homozygous individual can carry dominant or recessive alleles, but not both at a time. The heterozygous individual has both alleles, one dominant and one recessive.
Type of gametes produced Only one type of gamete is produced. Two types of gametes are produced.

Definition of homozygote

Homo it means " same ", is zygous yes refers to " have zygotes of a specific type ", therefore we can elaborate it saying that" when both alleles present on the homologous chromosomes for a given gene are the same, they are called homozygotes.

When two genes share easily detectable sequence similarities (nucleotide sequence in DNA or amino acid sequence) in the proteins they code, they are counterparts . If two homologous genes occur in the same species as those said to be paralogical and their protein products are Paralog .

An organism is said to be homozygous in a specific locus when it carries two indistinguishable (identical) copies of the gene that affects a trait present on the two reciprocal homologous chromosomes. (for example, the genotype RR or rr when R and r refer to the different possible alleles of the same gene). Such a cell or organisms are called homozygotes.

Definition of Heterozygotes

Straight it means "different" is cheekbone it means " have zygotes of a specified type "So we can explain it by saying that when both alleles are present on the homologous chromosomes for a given different gene.

For example, one chromosome in homologous pair contains brown hair (R) and another chromosome contains black hair (r). Hence the resulting genotype Rr. Schematic representation of homozygotes vs heterozygotes

Key differences between homozygotes and heterozygotes

  1. If diploid organisms carry two copies of each gene, they can be so-called identical alleles homozygotes, while if diploid organisms carry two copies of each gene, which can be different (dominant and regressive) alleles, we can say how heterozygous .
  2. Homozygous results in similar individuals they mean that pure for a stretch and true breeds. For example, RR, rr; while it carries different individuals, which means that the heterozygous individual is rarely pure and produces offspring with a different genotype. For example Rr
  3. The homozygote carries similar alleles all of a sudden. For example RR, rr, while heterozygous carriers dissimilar allele e.g. Rr.
  4. A homozygous individual can carry a dominant or recessive allele, but not both at once; a heterozygous individual has both, that is, a dominant allele and a recessive allele.
  5. Only a guy gamete is produced in homozygotes, while in heterozygotes they are produced two types of gametes.


We conclude that homozygotes and heterozygotes are the two genetic terms used in the identification of traits, which occur in an organism. When two organisms reproduce, they produce a trait that a combination of a series of dominant or regressive alleles. The way these alleles are combined will identify as they are homozygous or heterozygous.