Alleles Recessive

Recessive alleles: what are they and how do they affect our lives?

Genetics is a field of science that studies heredity and its mechanisms. Our body contains a huge number of genes that determine our appearance, behavior and health. Genes are found on chromosomes, and each gene has two versions called alleles. One allele is inherited from the father, and the other from the mother.

Alleles can be dominant or recessive. Dominant alleles appear in a genotype even if there is only one copy of that gene. Recessive alleles appear only in a homozygous or hemizygous state, that is, when both alleles in the genotype are the same.

Recessive alleles may not appear in the carrier if there is a dominant allele that masks their effect. But if both parents are carriers of a recessive allele, then their offspring are likely to inherit two recessive alleles and exhibit the associated phenotype.

An example of recessive inheritance is the hereditary genetic syndrome Phenylketonuria (PKU). This syndrome is caused by the absence of an enzyme that is necessary for the metabolism of phenylalanine, one of the amino acids. If both alleles of the gene responsible for this enzyme are recessive, then the child will inherit both alleles and will suffer from PKU. This can lead to developmental delays, mental retardation and other serious health problems.

Another example of recessive inheritance is the hereditary genetic syndrome of fly agaric poisoning. This syndrome is caused by the presence of a recessive allele that results in the inability to metabolize certain toxins found in fly agarics. If both alleles of this gene are recessive, then the person will be extremely sensitive to fly agarics and may die if they eat even a small amount of this mushroom.

Thus, recessive alleles can have a serious impact on our lives; their manifestation may depend on the presence of the corresponding alleles in both parents. Understanding the mechanisms of inheritance and genetic phenomena can help in the prevention and treatment of a number of diseases associated with genetic disorders.

_Allele_ is a genetics concept that denotes the form of a gene responsible for one trait. It can be dominant (A) or recessive (a). In all populations there are always both dominant and recessive homozygotes. The dominant trait manifests itself in heterozygotes (Aa) and in dominant homozygotes. A recessive trait is characteristic of individuals who have this allele, but in the homozygous state they do not exhibit this trait. In heterozygous aa genotypes, both alleles are combined as usual, which means both traits will manifest themselves. But in the case of recessive traits, homozygosity manifests itself phenotypically as the absence of properties inherent in a given allele. Both forms of genes are present in each individual, but their effect is neutral due to the fact that one has an insufficient amount of proteins for its expression.