BIOL 111- Midterm Exam Guide - Comprehensive Notes for the exam ( 17 pages long!)
Document Summary
Mendel"s laws explained by chromosome behavior in meiosis. We get the 3:1 ratio through meiosis. Random alignment in metaphase i leads to the independent assortment of alleles. Question: the a and b loci are on the same chromosome. Crossing over reduces the effects of linkage. The farther apart alleles are the easier it is to assort independently, the closer they are the more rare crossing over is. Crossover more likely to occur on loci that is far apart: the human genome. 1 pair of sex chromosomes: x and y. Karyotype: diagram of 22 autosomes and one sex chromosome: sex chromosomes: X chromosome much larger, many more loci than y chromosome. Y chromosome lacks many loci of the x chromosome. X linked loci: only present on x chromosome. No such thing as a heterozygous male (they only have one x chromosomes) Boys have 50% chance of being blind. It does matter that females have 2.