Chapter 46 Animal Reproduction. Overview of sexual reproduction.
Reproduction & Development (PB Lecture18 – Spring 2008 Althoff, reference Ch. 36) Animal...
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Transcript of Reproduction & Development (PB Lecture18 – Spring 2008 Althoff, reference Ch. 36) Animal...
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
PROSTATEGLAND
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
SEMINIFEROUSTUBULES
Site of gamete production
(_________ occurs here)
TESTES: site of gamete production, “__________” environment
SPERMP
____________(a lysosome)
MITOCHONDRIA
OVIDUCT
OVARYUTERUS
CERVIX
VAGINA
OVARIAN CYCLE
28-days in humans
here
occurs at this
stage
OVARYsite of
oogenesis
does NOT take place in the ovary!
1
2
3
45
6 7
Developing, ovulating,…and gone!
Theovary
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 folliclecorpus luteum
DAY OF MENSTRUAL CYCLE
HO
RM
ON
E C
ON
CE
NT
RA
TIO
N
0 14 28
HO
RM
ON
E C
ON
CE
NT
RA
TIO
N
DAY OF MENSTRUAL CYCLE
0 14 28
DAY OF MENSTRUAL CYCLE
0 14 28
TH
ICK
NE
SS
Uterinelining
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 layershave formed. Occurs 3rd week of development
Embryonic layer Adult 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 developat different times during pregnancy