BIO120H1 Lecture Notes - Lecture 4: Gregor Mendel, Meiosis, Dna Replication
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BIO120H1 Full Course Notes
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Bio120 - lecture 4: neodarwinism and the evolutionary significance of genetic variation. Requirements for darwin"s theory: variation, heredity, selection. But darwin had no understanding of genetics and the mechanism of inheritance. Used in relation to a particular gene or gene combinations. Used when discussing a trait or a feature of an organism that varies. Genome: entire organism"s dna including both genes and non-coding regions. Unit of hereditary information located on the chromosomes consisting of dna. Dna sequence composed of codons essential for a special biological function. Codons: sequence of 3 nucleotides that makes up genetic code. Mutation is the ultimate source of genetic variation. Stable change in dna sequence resulting in change of genotype. Occurs at very low but variable rate in all organisms. Effects: neutral, deleterious, lethal, beneficial in my cases fitness effects depend on environment. Important for evolution, must occur in germ cells (sperm/eggs) somatic mutations not inherited. Recombination generates new combinations of alleles, arises through mutations.
