BIOL 302 Chapter Notes - Chapter 7: Directional Selection, Heritability, Allopatric Speciation
17 Sep 2016
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Macroevolution: evolution in higher levels of organization. Evolution process depends on genetic variation and can occur through random processes or through selection. Chromosomes: compact structures of long strands of dna wound around proteins. Genes: regions of dna that code for a particular protein, affect particular traits. Alleles: different forms of a particular gene: diploid organisms have two sets of chromosomes, one from the mother and the other from the father"s gamete is haploid, which means it has 1 chromosome. Polygenic: single trait is affected by several genes: eye colour is an example of this. Epistasis: expression of one gene is controlled by another gene. Heterozygous: individual has two different alleles of a particular gene. Homozygous: individual has two identical alleles of a particular gene. Codominant: when two alleles contribute to the phenotype. Dominant: an allele that masks the expression of the other alleles.
