ANTHR-140 Lecture Notes - Lecture 5: Sickle Cell Trait, Haemophilia, Genetic Code
Document Summary
Genetic code: information to make proteins encoded in nucleotide base sequence. Codon sequence of 3 nucleotide bases which code for one amino acid. Gene: sequence of dna bases that carries info for synthesizing a particular protein and occupies a specific chromosomal locus. Dna splits in region and attracts complementary mrna. Outside nucleus @ribosome trna binds to complementary mrna bringing with them a. a. specified by mrna codon. Mendelian inheritance (single gene, autosomal, dom-recessive model) Useful for examining traits with qualitative variation. Polygenic traits: quantitative variation influences by more than 2 genes. Pleiotropy: single gene influences expression of multiple traits. Ex: stature influenced by diet, health, altitude. Types of genes: 5% structural and 95% regulatory. Gene pool- sum of alleles in population. Evolution: change in allele frequency from one generation to next. Genetic equilibrium- no change in allele frequency. Hardy- weinberg: determine if populations are evolving. Compares observed genotype frequency with predicted genotype frequency assuming no evolution is occuring.