Biology 1001A Lecture Notes - Lecture 11: Melanocortin 1 Receptor, Melanosome, Punnett Square
Document Summary
Bio 1001a - lecture 11 inheritance in populations. Mendel figured out how variation is inherited: explanatory model. Variation in traits due to different alleles. Organisms inherit two alleles for each trait. Appearance of heterozygotes determined by dominant alleles: punnett squares. Mendel"s dihybrid cross 9:3:3:1 ratio of genotypes: phenotypes depend on how gene products interact (biochemistry) Don"t know answer for dominant alleles clicker question. Pure-breeding black and pure-breeding brown pigs crossed together. Brown pigs have w allele, black pigs have b allele. Black turns out to be dominant trait all f1 are black. Cross of f1 + f1 resulted in mostly black, some brown offspring. Skin and hair pigmentation results from melanin. In this stimulation, there is black (eumelanin) and red melanin (pheomelanin: brown skin = production of both black and red melanin. How melanocyte changes the type of melanin it produces: melanocortin 1 receptor (mc1r) = membrane receptor on melanocyte.
