Sperm Egg Purpose Deliver haploid genetic information from male to the female’s egg. Provide haploid genetic information from the female, nourish the embryo until its placental or feeding stage, and provide cytoplasmic determinants that interact with nuclei. System A closed system except for water (H2O), gas (O2 and CO2) and limited ion exchange. Contents Haploid [...]

The egg must provide a nucleus (genetic informatino), specific regulatory molecules (mRNAs, cytoplasmic determinants) that interact with nuclei, and building materials for development (protein, carbon source) until the embryo’s feeding or placental stage. The volume of the egg can range from 103 (mammals, sea urchin) to 106 (amphibian) to 1011 (ostrich egg) times larger than [...]

A sperm’s role is to deliver a male’s nucleus (namely, the genetic information within) to the egg. Mature sperm lack ribosomes and mRNA; they are transcriptionally and translationally inactive. Component Overview Haploid Nucleus The sperm nucleus is very condensed, thus reducing its size for faster swimming. The sperm nucleus contains only DNA and positively charged [...]

Gametogenesis is the development of germ cells into gametes. Gametes are large nonmotile oocytes in females, and small motile sperm in males. Gametogenesis occurs in the gonads: ovaries in females and testes in males. The two main differences between oogenesis and spermatogenesis: prophase arrest; and unequal division. Step Start Result Overview Germ Cell Germ Cell [...]