Allelomorphs

ALLELOMORPHS (from Greek allelon- mutually and morphe- form), a genetic term denoting inherited traits that are paired in each individual and separate during the maturation of sex cells into two different gametes. From each allelomorphic pair of traits, an individual receives one trait from the father through the sperm and another from the mother through the egg. If an individual receives two different traits of the same allelomorphic pair from both father and mother, then for the most part one trait suppresses the other and is therefore called dominant, while the suppressed trait is called recessive. Such a heterozygous individual does not differ in appearance from a homozygous individual having both dominant traits in the corresponding allelomorphic pair, but differs genetically, since it passes the dominant trait to half of its offspring and the recessive trait to the other half. Examples of A. in humans: 1) the recessive trait for blue eyes corresponds to the allelomorphic dominant trait for dark eye color; heterozygotes have dark eyes; 2) the recessive trait for a normal hand is combined in one pair of A. with the dominant trait for a six-fingered hand; to this day only six-fingered heterozygotes are known, who pass the trait for six fingers to half of their offspring and the trait for a normal hand to the other half. The inherited traits of many other abnormalities are dominant in relation to the normal recessive trait; traits of some predispositions to certain diseases (diabetes, etc.), as well as the trait for some abilities (e.g., musical hearing), are usually considered recessive in relation to the normal dominant trait. In recent years, Morgan and his school have made it highly probable that the traits of each pair of A. correspond to certain material particles at certain points of known chromosomes. In the fertilized egg and in all body cells, all chromosomes are paired (in humans - 24 pairs), but during the maturation of sex cells, the chromosomes of each pair separate into different gametes, in which only 24 unpaired chromosomes are found. This explains the regular segregation of allelomorphic traits. n. Koltsov.