BSCI 207 Lecture Notes - Lecture 14: Mustard Plant, Androdioecy, Gonochorism
5 Oct 2016
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Definition of terms: gonochorism = two sexes, male and female. Dioecy for plants: hermaphrodite = one sex that makes both sperm and egg. Variations: ancestor of animals was likely a hermaphrodite, sexual systems can switch very fast. Mustard plant also transitioned to selfing recently. Receptor gene that normally killed pollen from the same organism was fragmented into many pieces through mutations. Animal life cycles can mix outcrossing and asexuality: in daphnia: During times of stress (cold or lack of food) eggs are fertilized and are made into a resistant resting egg . Animals can also exhibit a complete commitment to asexuality: cnemidophorus uniparens lizards. Formed as a cross between two species. Parthenogenesis developed spontaneously to keep the lineage alive. Asexual reproduction can occur without the development of an embryo. Aquatic fungi were probably haplodiplontic and anisogamous. Movement onto land altered mode of reproduction: became haplontic, became isogamous.
