Lecture Date ________ u Chapter 46 ~ Animal Reproduction

Overview u Asexual (one parent) u fission (parent separation) u budding (corals) u gemmules (porifera) u fragmentation & regeneration (inverts) u Sexual (fusion of haploid gametes) u gametes (sex cells) u zygote (fertilized egg) u ovum (unfertilized egg) u spermatozoon (male gamete)

Reproductive cycles u Parthenogenesis unfertilized egg development; haploid, sterile adults (honeybees) u Hermaphroditism both male & female reproductive systems; sessile & burrowing organisms (earthworms) u Sequential hermaphroditism reversal of gender during lifetime protogynous (female 1st) protandrous (male 1st)

Mechanisms of sexual reproduction u Fertilization (union of sperm and egg) external internal u Pheromones chemical signals that influence the behavior of others (mate attractants)

Mammalian reproduction, I u The Human Male u Testes ~ male gonads u Seminiferous tubules ~ sperm formation u Leydig cells ~ hormone production u Scrotum ~ outside body temp. u Epididymis ~ sperm development u Vas deferens ~ sperm propulsion u Seminal vesicles ~ semen u Prostate gland ~ anticoagulant; nutrients u Bulbourethral glands ~ acid neutralizer u Penis/urethra ~ semen delivery

Mammalian reproduction, II u The Human Female u Ovaries ~ female gonads u Follicle ~ egg capsule u Corpus luteum ~ hormone secretion u Oviduct ~ fertilization u Uterus/endometrium ~ womb/lining u Cervix/vagina ~ sperm receptacle

Spermatogenesis u Puberty until death! u Seminiferous tubules ~ location u Primordial germ cell (2N)~ differentiate into…. u Spermatogonium (2N) ~ sperm precursor u Repeated mitosis into…. u Primary spermatocyte (2N) u 1st meiotic division u Secondary spermatocyte (1N) u 2nd meiotic division u Spermatids (1N)~ Sertoli cells…. u Sperm cells (1N)

Oogenesis u As embryo until menopause... u Ovaries u Primordial germ cells (2N) u Oogonium (2N) u Primary oocyte (2N) u Between birth & puberty; prophase I of meiosis u Puberty; FSH; completes meiosis I u Secondary oocyte (1N); polar body u Meiosis II; stimulated by fertilization u Ovum (1N); 2nd polar body

The female pattern u Estrous cycles/estrus (many mammals) u Menstrual cycle (humans and many other primates): u Ovarian/Menstrual cycles~ follicular phase ~follicle growth ovulation ~ oocyte release luteal phase ~ hormone release

Embryonic & fetal development u Gestation ~ pregnancy u 1st trimester: u organogenesis u fetus (week 8; all adult features) u HCG hormone (menstruation override; pregnancy test detection) u Parturition ~birth u Labor ~uterine contractions u Lactation ~prolactin & oxytocin