BIOLOGY 151 Lecture Notes - Lecture 32: Genetic Marker, Chromosome, Heritability
Document Summary
Multiple alleles- 3 or more variants in a population, phenotype depends on which 2 alleles are inherited, abo blood types in humans. Sex-linked inheritance- allele is dominant in one sex but recessive in the other. A man and a woman could have the same genotype but express a different phenotype. Females have random x inactivation, where some cells express one chromosome and some express others. All traits that are on different chromosomes sort independently. If a gene on a chromosome is really far apart, it is more likely to cross over. The frequency of recombination is smaller for genes that are closer together. Expected frequency of recombination between genes is dependent on the distance between adjacent genes. Y-linked genes: if only males exhibit the trait, females do not inherit or transmit the trait and all sons of males with the trait also show the trait.
