BIOL239 Study Guide - Midterm Guide: Sister Chromatids, Y Chromosome, Reciprocal Cross
12 Apr 2014
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Genetic traits are passed on from one generation to the next. Artificial selection: purposeful matings to select for particular desired traits: ex. Gregor mendel (1822- 1884) is known as the father of genetics. Self- fertilization ensured that the genetic line was pure by breeding the plant with itself. Genotype: genetic makeup; description of genetic information (genes or alleles) that are carried by an individual. Phenotype: observable characteristics; the physical/visual outcome of a genetic combination. Largely determined by genotype: commonly referred to as a trait. Self- fertilize the progeny (interbreed) so that the second filial (f2) generation has no new genes coming in from other individuals. In the f2 progeny, the lost trait disappears; 3:1 ratio. Test cross: a cross against a homozygous recessive phenotype. If crossing with homozygous dominant, the offspring are identical. If crossing with heterozygote, 1:1 ratio in the offspring; recessive allele is uncovered. Pleiotrophy: multiple phenotypic effects caused by a single gene.
