BIO 311D Lecture 1: Meiosis & Sexual Life Cycles Lecture Notes
Document Summary
Cluster of organic molecules& aggregation of them in water. Independent assortment main source of genetic variability; during meiosis i, homologous pairs are lined up in the middle, each homologous pair (tetrad) lines up by itself. Each alignment is random; different homologous line up independently and randomly. Crossing over/ genetic recombination maternal and paternal homologous exchange segments. Sexual reproduction in diploid 2n (self-fertilization also counts) O(cid:373)e have elo(cid:374)gate (cid:272)ell (cid:862)h(cid:455)pha(cid:863) to (cid:373)a(cid:454)i(cid:373)ize surfa(cid:272)e area. Me(cid:374)del"s pri(cid:374)(cid:272)iple of segregatio(cid:374) of alleles homologs separate in meiosis i. Principle of independent of assortment each tetrad separate independently of each other. Traits seem to disappear then reappear in future generations. Traits seem to be inherited as units, not blended. Only 2 possible alleles per gene locus. Monohybrid cross mating between two individuals who are heterozygous; one trait only (e. g. Aabb x aabb) know all possible gametes (ab, ab, ab, ab) Incomplete dominance heterozygote has a phenotype unlike either homozygote.
