What is the difference between homozygous and heterozygous?
Human beings are examples of diploid organisms. They are known to contain allele pairs which are described as homozygous and heterozygous.
The core difference between homozygous and heterozygous is that homozygous carry identical alleles while heterozygous carry different alleles.
What Is Homozygous?
Homozygous is an individual organism carrying an identical pair of alleles such as RR or rr. The homozygous trait is when the same kind of two alleles associate to form a trait.
Both dominant and recessive alleles will be portrayed in the offspring. Homologous genes are only present in organisms of the same species.
What Is Heterozygous?
Heterozygous is an individual organism carrying a different pair of alleles such as Rr. Here two types of gametes are responsible for the development of the heterozygous organism.
Besides that, both recessive and dominant genes can be seen in the offspring such as Rr where R is dominant and r is recessive.
Comparison Table: Homozygous Vs Heterozygous
| Basic Terms | Homozygous | Heterozygous |
| Meaning | Occurs when the diploid organism carry identical alleles | Occur when the diploid organism carry different alleles |
| Result | Pure traits such as RR or rr | Dissimilar traits such as Rr |
| Carries | Identical alleles | Different alleles |
| Type of alleles | Either dominant or recessive | One dominant and the other recessive |
| Gametes produced | One type | Two different types |
| Vigour | Does not exhibit extra vigor | Exhibit extra vigor such as hybrid vigor |
| Self-breeding | Same trait over generations | Combination of different traits |
| Examples | Human blood type O | Human blood type AB |
Core Difference between Homozygous and Heterozygous
- Homozygous results in similar individuals with pure traits while heterozygous results in dissimilar individuals with different traits.
- Homozygous have identical alleles while heterozygous have different alleles
- Homozygous is either dominant or recessive while heterozygous have one dominant and one recessive.
- Only one gamete is used in homozygous while heterozygous two types of gametes are used.
- Homozygous do not exhibit extra vigor while heterozygous exhibit hybrid vigor
Core Similarities between Homozygous and Heterozygous
- Both used in the description of genotype
- Both present on the same locus of homologous chromosomes.
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Comparison Video
Conclusion
The genotype of an individual is described by both homozygous and heterozygous. These two terms describe the location of alleles on the homologous chromosomes.
Understanding the core difference between homozygous and heterozygous is quite important during competitive exam revision.
More Sources and References
- Homozygous. Healthline
- Introduction to Genetics. Khan Academy