Understanding Heterozygous

Heterozygous is a term used in genetics to describe an individual who has two different alleles for a particular gene. Alleles are different versions of the same gene, and they can be dominant or recessive.

For example, let's consider the gene for hair color. The allele for brown hair (B) is dominant, while the allele for blonde hair (b) is recessive. An individual who has one allele for brown hair and one allele for blonde hair (Bb) is said to be heterozygous for the hair color gene.

Study Guide for Heterozygous

1. Definition: Heterozygous refers to an individual who has two different alleles for a specific gene.
2. Punnett Square: Heterozygous individuals can be represented using a Punnett square, a diagram that is used to predict the possible genetic outcomes of a cross between two individuals.
3. Dominant and Recessive Alleles: In a heterozygous individual, one allele is dominant and the other is recessive. The dominant allele determines the phenotype (physical characteristics), while the recessive allele is not expressed in the presence of the dominant allele.
4. Genetic Diversity: Heterozygosity contributes to genetic diversity within a population, as it allows for different combinations of alleles to be passed on to offspring.
5. Health and Disease: In some cases, being heterozygous for certain genes can confer a selective advantage. For example, being heterozygous for the sickle cell gene can provide resistance to malaria.