Reproduction & Development (PB Lecture18 – Spring 2008 Althoff, reference Ch. 36) Animal Reproduction Human Reproduction Animal Development

Modes of Reproduction ______________ budding (in Hypha ) parthenogenesis (in some insects, lizards, salamanders) spontaneous fission (planaria) _____________ “true” hermaphoditism (rare, few insects) _____________ fertilization—union of gametes from two different individuals

HYDRA LIFE CYCLE

BUDDING…. by Hydra ( who also carrying on sexual reproduction )

Asexual Reproduction ____________________--females (of some species) reproduce without fertilization…resulting in haploid offspring. Some species can do this AND sexual reproduction example: Aphids can do both: no wasted energy or gametes in midst of plenty

Aphid “taps” into phloem tissue of plants (the “sugar” pipeline)….so, rich source of energy and other nutrients allows for optimum production of young…without having to find a mate !!!!

Some species… it is a ________ world only, thus, considered _________species FISH: mollies and platies LIZARDS: whiptails

Planaria Spontaneous (binary) fission

Sexual Reproduction: the norm among Animalia species Some species have “both sets” of sex organs (hermaphroditic: earthworms example) Just one set of sex organs ( or ) is the norm Two basic categories: ______________ fertilization—most primitive ______________ fertilization—most advanced

Human Reproduction Reproductive system consists of 2 components: (1) _______: testes or ovaries which produce gametes and sex hormones (2) ________________: a) males: conduct (move) gametes b) females: house embryo/fetus

TESTIS PENIS Bladder Urethra EPIDIDYMIS VAS DEFERENS SEMINAL VESICLE PROSTATE GLAND testes epididymis vas deferens bulbourethral gland prostrate gland seminal vesicle urethra penis B.G.

Semen Combination of _________ + secretions from 3 glands: 1) seminal vesicles: thick, viscous fluid containing _________ for possible use by sperm 2) prostrate gland: milky, ________ fluid that a) activates/increases sperm motility b) protects sperm in vagina’s low pH (3.8 to 4.5) environment 3) bulbourethral glands: muscous secretions with a ____________ effect (some pre- ejaculate fluid)

EPIDIDYMUS TESTIS SEMINIFEROUS TUBULES Site of gamete production (_________ occurs here) TESTES: site of gamete production, “__________” environment

SPERMP ____________ (a lysosome) MITOCHONDRIA

OVIDUCT OVARY UTERUS CERVIX VAGINA

OVARIAN CYCLE 28-days in humans here occurs at this stage

OVARY site of oogenesis does NOT take place in the ovary!

Developing, ovulating, …and gone! The ovary

Follicle  Ovulation  Evidence of Ovulation  New __________ containing primary oocyte  Developing follicle  Mature follicle with secondary oocyte  ______________ – egg erupts from ovary into oviduct…”ruptured follicle remains  Egg goes into oviduct, “that” follicle is done for life. But, if pregnancy occurs it will become a _________________ (easily detected) producing primarily ______________  & 7 No pregnancy, then “that” corpora luteum reduces in size and quits producing progesterone

Menstrual Cycle - Under hormonal control GnRH - gonadotropin-releasing hormone FSH - follicle stimulating hormone LH - lutenizing hormone ESTROGEN PROGESTERONE WHERE DO THESE HORMONES COME FROM?

________ (HT) _______ (AP) ______ (AP) ___________(OV) _______________ (OV) HT =hypothalamus AP = anterior pituitary OV = ovary (oocyte  follicle  corpus luteum

DAY OF MENSTRUAL CYCLE HORMONE CONCENTRATION 01428

HORMONE CONCENTRATION DAY OF MENSTRUAL CYCLE 01428

DAY OF MENSTRUAL CYCLE THICKNESS Uterine lining menstruation

Post - ovulation 1) SECONDARY OOCYTE (EGG) enters OVIDUCT with action by fimbriae 2) sperm “meets” egg somewhere in oviduct resulting in _______________ 3) ___________ results, and travels on 4) ______________ develops and implants in the _________________ 5) _____________ develops into ________

= when 3 germs layers have formed. Occurs 3 rd week of development

Embryonic layerAdult tissue Ectoderm Mesoderm Endoderm GERM LAYERS  specific tissues/organs

Human embryo at beginning of week 5 SOMITES

The PLACENTA – the most ______________ “support” structure for development

PLACENTA Maternal blood and fetal blood never mix… because exchange occurs across the ___________________ Chorionic villi: ______________  fetal side ______________  maternal side Risk: harmful chemicals moving across placenta to fetal side… _______________ during EMBRYONIC (0-90 days) stage because various structure first forming OTHER TIMES (including 3-9 months) different organs “at risk” because they develop at different times during pregnancy