What is the Difference Between Homozygous and Heterozygous?
🆚 Go to Comparative Table 🆚The difference between homozygous and heterozygous lies in the alleles an organism inherits from its parents for a specific trait. Alleles are different versions of a gene that can lead to variations in traits, such as physical appearance or behavior.
- Homozygous: An organism is considered homozygous when it inherits the same allele for a specific trait from both parents. This can result in either a homozygous dominant or homozygous recessive state, depending on the allele's dominance. For example, if an organism has two copies of the allele for brown hair (BB), it is homozygous dominant for that trait.
- Heterozygous: An organism is considered heterozygous when it inherits different alleles for a specific trait from each parent. In a heterozygous state, the organism has one dominant allele and one recessive allele. The dominant allele is typically expressed, while the recessive allele is masked. For example, if an organism has one allele for brown hair (B) and one allele for blonde hair (b), it is heterozygous for that trait.
In summary, the main difference between homozygous and heterozygous is that homozygous organisms have two identical alleles for a specific trait, while heterozygous organisms have two different alleles for the same trait.
Comparative Table: Homozygous vs Heterozygous
The terms homozygous and heterozygous are used in genetics to describe the types of alleles an individual possesses for a particular gene. Here is a table highlighting the differences between homozygous and heterozygous:
| Feature | Homozygous | Heterozygous |
|---|---|---|
| Definition | Both alleles for a specific gene are identical (e.g., RR or rr). | An individual possesses two different alleles for a specific gene (e.g., Rr). |
| Alleles | Contains two identical copies of the same allele coding for a particular trait. | Contains two different copies of alleles coding for a particular trait. |
| Types | Can be either homozygous dominant (where both alleles are dominant) or homozygous recessive (where both alleles are recessive). | Heterozygous alleles can show complete dominance, codominance, or incomplete dominance. |
| Self-fertilization | Results in the repetition of the same traits over generations. | Results in different combinations of traits over the next generations. |
| Gamete Production | Only one type of gamete is produced. | Two types of gametes are produced. |
Homozygous individuals carry two identical alleles for a specific gene, while heterozygous individuals carry two different alleles for the same gene. The expression of a trait in an individual is determined by the specific combination of alleles they possess, and in certain instances, one of these alleles can show dominance, resulting in the physical characteristic being influenced. Heterozygous individuals contribute to genetic diversity within populations, which plays an important role in the evolution and adaptation of species.
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- Haploid vs Diploid
- Dominant vs Recessive Alleles
- Allele vs Genotype
- Codominance vs Multiple Alleles
- Dominant vs Recessive
- Homosexual vs Heterosexual
- Gene vs Allele
- Monohybrid vs Dihybrid Crosses
- Homologous vs Homeologous Chromosomes
- Homoplasy vs Homology
- Homogeneous vs Heterogeneous
- Genotype vs Phenotype
- Genetics vs Heredity
- Homodimer vs Heterodimer
- Allelic vs Locus Heterogeneity