BLG 400 Lecture Notes - Lecture 3: Allosome, Y Chromosome, Pseudoautosomal Region
Document Summary
Mitosis: nuclear division that generates 2 daughter cells containing the same number and type of chromosomes as parent cell. Meiosis: nuclear division that generates gametes (egg and sperm) containing half the number of chromosomes found in other cells. Fertilization is the union of haploid gametes to produce diploid zygotes. Fertilized eggs carry matching sets of chromosomes, one set from maternal gamete and one set form paternal gamete. Gametes are haploid (n: carry only a single set of chromosome. Zygotes are diploid (2n: carry 2 matching sets of chromosome. Mitosis ensures that all cells of developing individuals have identical 2n chromosome sets. Metaphase chromosomes can be classified by centrosome position: Metacentric chromosome: centromere is in the middle. Homologous chromosomes are matched in size, shape and banding patterns: Homologues: contain the same set of genes but can have different alleles for some genes. Nonhomologues: carry completely unrelated sets of genes. Karyotype: micrograph of stained chromosomes arranged in homologous pairs.