BIOL308 Lecture 6: Lecture 6- Xmes
11 Jun 2017
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Total # of chromosomes in each cell of humans (except gametes): 46 chromosomes (23 pairs) humans have 22 autosomal pairs + xx (or y) (sex) = 23 pairs of homologous chromosomes. Creates gametes = egg 22+x 22+x(ory)- 22 autosomal chromosomes + one sex. Germ cells formed by mitosis (2n as well)- will go through meosis and form gametes (n) Gametophyte = haploid form of an organism can grow through mitotic division of 1n. Cells differentiate and form different tissues = gametophyte. Male and female gametes fuse (fertilization) into 2n zygote zygote (mitosis and differentiate) into diploid form = sporophyte in specific organs 2n cells go through meiosis to form 1n spores an organism gametophyte grows through mitosis from 1n spore. Asexual reproduction organism produces an exact copy of itself (occurs in all prokaryotes and some eukaryotes) Sexual reproduction diploid organisms (2n chromosomes) fertilization (fusion of 1n gametes) progeny is produced through meiosis and fusion of gametes.
