BIOL 211 Lecture Notes - Lecture 6: Asexual Reproduction, Multicellular Organism, Y Chromosome
Document Summary
Three types of cell division: binary fission (prokaryotes, mitotic cell division (eukaryotes, meiotic cell division (eukaryotes) Meiosis: a parent cell divides to form four daughter cells that have only half as many chromosomes as the parent; each daughter cell is usually genetically different from the parent cell. Since somatic cells typically have two sets of chromsomes, the number of chromosomes in a cell is usually 2n, called diploid. Gametes contain only one set of chromosomes; called haploid, number of cells is n. Though the genes on the maternal and paternal chromosomes code for the same products, they might code for slightly different versions of those products: alleles different versions of the same genes. Diplontic life cycle: gametes, produced by meiosis, are the only haploid cells in the life cycle, fertilization produces a diploid zygote, which undergoes mitosis to produce a multicellular, diploid organism, characteristic of most animals (including humans)
