BIO260H1 Lecture Notes - Sister Chromatids, Meiosis, Centromere
Document Summary
Loci = location of gene on a chromosome. Homologous chromosomes = members of the same diploid chromosome pair (can be aa or aa or aa doesn"t matter) Heterozygous chromosomes = two chromosomes with two different alleles (aa) Homozygous chromosomes = same alleles on both chromosomes in a pair (aa or aa) Sister chromatids = appear during replication, when a chromosome replicates itself and as a result you end up with two chromosomes that are identical (must be homozygous) 2n: simply implies that the chromosomes we are talking about exist in diploid pairs n: number of centromeres. Centromeres = that pinch in the middle that holds two sister chromatids together. C = absolute number of chromosomes (dna content) During meiosis cells undergo two different kinds of division reductional and equational division. At metaphase i the homologous chromosomes separate and replicate doubling the value of c while the value of n remains the same.