Sexual reproductionin Chlamydomonasreinhardtiiplus agglutininsminusagglutininsFusionMeiosisZygoteMatingGGametogenesis
Sexual reproduction in Chlamydomonas reinhardtii 6
Sexual dimorphismSecondarysexualdifferentiationPrimarysexualdifferentiation(gonads)
Sexual dimorphism Secondary sexual differentiation Primary sexual differentiation (gonads)
Unisexual vs. BisexualasselsHermaphrodite（雌雄同体）
Unisexual vs. Bisexual Hermaphrodite (雌雄同体)
1. Different sex determining systemDNuclearstructureoftheGrasshoppersperm
1. Different sex determining system Nuclear structure of the Grasshopper sperm
(a)Eg. 1 Nematodes(b).Caenorhabditiselegans· XX/XO systemHermaphroditeSelf-fertilizationXXX.Ratio of sex chromosomes toMaleHermaphroditeautosomes(<1%)(>99%)Cross-fertilization42X/2A=1XXX.1X/2A=0.5MaleHermaphrodite(50%)(50%)
Eg. 1 Nematodes • Caenorhabditis elegans • XX/XO system • Ratio of sex chromosomes to autosomes • ♀ 2X/2A=1 • ♂ 1X/2A=0.5 XX X XX X