BIOL 121 Lecture Notes - Meiosis, Y Chromosome, Allosome

• School: UBC
• Department: Biology
• Course: BIOL 121
• Professor: All

Document Summary

If phenotype is due to an autosomal recessive allele. If parents of an affected individual do not have the trait. Change in a gene (mutant = individuals with mutated traits) Set of matings where mother"s phenotype in first cross is father"s phenotype in second cross; and father"s phenotype in first cross is mother"s phenotype in second cross. Sex chromosomes refer to the x and y chromosomes in organisms. X and y chromosomes are different in size and shape the y chromosome is smaller. However, they have regions that are similar enough to lead to proper pairing during prophase i of meiosis i. The gene for a trait is located on the x chromosome and the y chromosome does not carry an allele for the gene. Though x and y chromosomes synapse during prophase i, they differ in size, shape and gene content. The physical association of genes that are found on the same chromosome.