Biology 1201A Lecture Notes - Lecture 2: Bacterial Conjugation, Paramecium, Mating Type
14 Dec 2019
School
Department
Course
Professor
Document Summary
Most mammals: xx = female, xy = male. Birds, some fish, insects, reptiles: wz = female, zz = male. Becomes female when it is bigger, lower in stack. Mating type determined by several linked genes. Sex is the exchange of genetic material between individuals. In sexually reproducing organisms, gametes fuse to generate new combinations of alleles. With sex comes recombination eg. in producing gametes, exchange of alleles due to crossing-over in meiosis i. Reproduction by female from unfertilized eggs (no sex) Egg remains diploid during gamete formation or reduced to haploid then haploid genome duplicated. Unicellular organisms, usually haploid (but any ploid) All of an individuals genes are passed on to off-spring. Only half of an individuals genes are passed on to off-spring. Fitness (genetically) for sexual population is 2 times lower. Sex does not directly change the frequencies of alleles. Remember: non-random mating changes genotype frequencies, but not allele frequencies. No, sex does not make evolution faster.
