ANT331H5 Lecture 2: ANT331 – Lecture 2 Study Notes
Document Summary
Ant331 lecture 2 sexual reproduction and sexual development. Sexual reproduction: variation only 50% of genes from each parent, haploid ovum. Benefits of asexual reproduction: all else being equal, a parthenogenetic female will reproduce her genes at twice the rate. Larger, immobile: bulky cytoplasmic mass, will contribute energy to the growing zygote, sociobiology - parental role of females: ovum carries nutrients, has a large energy cost - Male gamete (sperm: smaller, streamlined, greater mobility, energetically cheaper to produce, sociobiology - goal is to mate for males: sperm travels very fast in search of the ovum with the goal of fertilizing it. The role of gonadal sex differentiation - alfred jost removed gonads of undifferentiated embryonic rabbits in both genetic females and males: all formed female phenotypes, transplanted embryonic testis, all formed male phenotypes. Gonadal hormones are released at sexual maturity to induce secondary sex traits.
