What exactly is dominance?
Dominance
Dominance is the phenomenon in genetics when one allele (variant) of a gene on one copy of a chromosome obscures or overrides the impact of another allele (variant) of the same gene on the other copy of the chromosome. Dominant refers to the first variation, and recessive to the second. A mutation in one of the genes, either new or inherited, is what initially causes this condition of having two distinct forms of the same gene on each chromosome.
The variants of genes on non-sex chromosomes, along with their connected traits, are referred to as autosomal dominant or autosomal recessive, whereas those on sex chromosomes are referred to as the X-linked dominant or recessive or Y-linked. Their presentation patterns and inheritance depend on the sex of both the child and the parent. Y-linked features cannot be dominant or recessive, as there is only one copy of the Y chromosome.
Other types of dominance include codominance, in which various variations on each chromosome both manifest their associated qualities, and incomplete dominance, in which a gene variant has a partial influence as opposed to when it is present on both chromosomes.
Thus, dominance is an effect of heredity, where out of two gene variants, one of the alleles masks the expression of the other for a particular trait.
- The allele which masks the other allele is known as the dominant allele.
- The allele which gets masked is known as the recessive allele.
- This effect is known as dominance.
Related Questions
Dominance
Dominance is the phenomenon in genetics when one allele (variant) of a gene on one copy of a chromosome obscures or overrides the impact of another allele (variant) of the same gene on the other copy of the chromosome. Dominant refers to the first variation, and recessive to the second. A mutation in one of the genes, either new or inherited, is what initially causes this condition of having two distinct forms of the same gene on each chromosome.
The variants of genes on non-sex chromosomes, along with their connected traits, are referred to as autosomal dominant or autosomal recessive, whereas those on sex chromosomes are referred to as the X-linked dominant or recessive or Y-linked. Their presentation patterns and inheritance depend on the sex of both the child and the parent. Y-linked features cannot be dominant or recessive, as there is only one copy of the Y chromosome.
Other types of dominance include codominance, in which various variations on each chromosome both manifest their associated qualities, and incomplete dominance, in which a gene variant has a partial influence as opposed to when it is present on both chromosomes.
Thus, dominance is an effect of heredity, where out of two gene variants, one of the alleles masks the expression of the other for a particular trait.
- The allele which masks the other allele is known as the dominant allele.
- The allele which gets masked is known as the recessive allele.
- This effect is known as dominance.
