students test – thursday transport – friday ap commitment forms – to me or guidance ap checks...
TRANSCRIPT
Students•Test – Thursday •Transport – Friday•AP Commitment forms – to me or Guidance•AP checks – to me
Chapter 46: Animal Reproduction1. What are the 2 ways that animals reproduce?
- Asexual – mitosis – same genes as parent- Fission – separation of a parent into 2 or individuals of the same size- Budding – individuals split as an outgrowth from an existing one
- Some cnidarians- Fragmentation – breaking of the body into several pieces followed by
regeneration- Sponges, cnidarians, tunicates
- Sexual – fusion of haploid gametes- Motile sperm swims to non-motile egg- Increases genetic variability
2. What are the 2 types of sexual reproduction?- External – eggs shed by female & fertilized by male in wet environment
- Courtship behaviors involved- Pheromones used
- Internal - sperm deposited in or near female reproductive tract & fertilized within female- Fewer zygotes but more parental care- Embryo develops in reproductive tract
Figure 46.5 External fertilization
Eggs
Chapter 46: Animal Reproduction1. What are the 2 ways that animals reproduce?2. What are the 2 types of sexual reproduction?
- External – eggs shed by female & fertilized by male in wet environment- Courtship behaviors involved- Pheromones used
- Internal - sperm deposited in or near female reproductive tract & fertilized within female- Fewer zygotes but more parental care- Embryo develops in reproductive tract
3. What is parthenogenesis?- Process in which an egg develops without fertilization- Produces haploid adults that produce eggs without meiosis- Daphnia (water flea), bees (male drones), wasps, ants
Figure 46.3 Sexual behavior in parthenogenetic lizards
Time
Ova
rysi
zeH
orm
ones
Beh
avio
r
Ovulation Ovulation
ProgesteroneEstrogen
Female-like
Male-like
Female-like
Male-like
(a) Both lizards in this photograph are C. uniparensfemales. The one on top is playing the role of a male. Every two or three weeks during the breeding season, individuals switch sex roles.
(b) The sexual behavior of C. uniparens is correlated with the cycle of ovulation mediated by sex hormones. As blood levels of estrogen rise, the ovaries grow, and the lizard behaves like a female. After ovulation, the estrogen level drops abruptly, and the progesterone level rises; these hormone levels correlate with male behavior.
Chapter 46: Animal Reproduction1. What are the 2 ways that animals reproduce?2. What are the 2 types of sexual reproduction?3. What is parthenogenesis?4. What does the male reproductive tract look like?
Seminal vesicle
(Rectum)
Vas deferens
Ejaculatory duct
Prostate gland
Bulbourethral gland
(Urinarybladder)
(Pubic bone)
Erectiletissue of
penis
Urethra
Glans penis
Prepuce
Vas deferens Epididymis
Testis
Scrotum
Figure 46.10 Reproductive anatomy of the human male
External – scrotum & penisInternal – gonads produce sperm & hormones
- testes – packed with highly coiled seminiferous tubules- accessory glands that help sperm movement
- seminal vesicles - bulbourethral glands- prostate gland
Erectile tissueof penis
Prostate gland
(Urinarybladder)
Bulbourethral gland
Vas deferensEpididymisTestis
Seminalvesicle(behind bladder)
Urethra
Scrotum
Glans penis
5. Where do the sperm travel during ejaculation?Propelled from epididymis vas deferens ejaculatory duct
6. How many sperm are released during ejaculation? 2 – 5 mL of semen per ejaculationx 50 – 130 million sperm per mL 100 – 650 million sperm per ejaculation
7. What happens after ejaculation?- Prostaglandins in semen thin mucus as the opening of the uterus &
stimulate uterine contractions which help semen move up uterus- Semen (slightly alkaline) neutralizes vagina (slightly acidic)
- Protects sperm & increases motility- Initially sperm are coagulated & become liquified so sperm can swim
8. How does viagra work?- Promotes the action of nitric oxide (NO) which enhances relaxation of
smooth muscle in blood vessels of penis so blood can enter erectile tissue
9. What does the female reproductive anatomy look like?
Figure 46.9 Reproductive anatomy of the human female
Glans
(Rectum)
Cervix
Vagina
Bartholin’s gland
Vaginal opening
Ovary
Oviduct
Labia majora
Labia minora
(Urinary bladder)
(Pubic bone)
Uterus
Urethra
Shaft
Prepuce Clitoris
External – clitoris & 2 sets of labia which surround the clitoris & vaginal openingInternal – pair of gonads (ovaries) with ducts & chambers for gametes & fetus
Vagina
Uterus
Cervix
OvariesOviduct
Uterine wallEndometrium
Follicles
Corpus luteum
Ovaries – contain many follicles- Follicle – all formed before birth
- egg cell surrounded by follicle cells which nourish & protect the egg- produce estrogens
- Endometrium – inner lining of uterus- After ovulation, “egg” falls down the oviduct into uterus
7. What happens after ejaculation?- Prostaglandins in semen thin mucus as the opening of the uterus &
stimulate uterine contractions which help semen move up uterus- Semen (slightly alkaline) neutralizes vagina (slightly acidic)
- Protects sperm & increases motility- Initially sperm are coagulated & become liquified so sperm can swim
8. How does viagra work?- Promotes the action of nitric oxide (NO) which enhances relaxation of
smooth muscle in blood vessels of penis so blood can enter erectile tissue9. What does the female reproductive anatomy look like?10. How are “eggs” made?
- Oogenesis
Figure 46.11 Human OogenesisOvary
Primary germ cell in embryo
Differentiation
OogoniumOogoniumin ovary
Mitoticdivision
Primary oocyte,arrested in prophaseof meiosis I(present at birth)
Completion of meiosis Iand onset of meiosis II
Primaryoocytewithinfollicle
Secondary oocyte,arrested at meta-phase of meiosis II
Firstpolarbody
Ovulation
Entry ofsperm triggerscompletion ofmeiosis II
Ovum
Growingfollicle
Mature follicle
Rupturedfollicle
Ovulatedsecondary oocyte
Corpus luteum
Degeneratingcorpus luteum
2n
2n
nn
nn
Secondpolarbody
Follicles grow in response to FSH completing meiosis I & stopping at metaphase II
Smaller polar body is discardedSecondary oocyte is ovulated…NOT AN EGGMeiosis is completed IF 2° oocyte is fertilizedAfter ovulation, remaining tissue reorganizes to
form the corpus luteum
7. What happens after ejaculation?- Prostaglandins in semen thin mucus as the opening of the uterus & stimulate
uterine contractions which help semen move up uterus- Semen (slightly alkaline) neutralizes vagina (slightly acidic)
- Protects sperm & increases motility- Initially sperm are coagulated & become liquified so sperm can swim
8. How does viagra work?- Promotes the action of nitric oxide (NO) which enhances relaxation of smooth
muscle in blood vessels of penis so blood can enter erectile tissue9. What does the female reproductive anatomy look like?10. How are “eggs” made?
- Oogenesis 11. How are sperm made?
- Spermatogenesis
EpididymisSeminiferous tubule
Testis
Cross sectionof seminiferoustubule
Sertoli cellnucleus
Lumen ofSeminiferous tubule
Spermatogonium
Primary spermatocyte(in prophase of meiosis I)
Secondary spermatocyte
Earlyspermatids
Spermatids(at two stages ofdifferentiation)
Differentiation(Sertoli cells providenutrients)
Meiosis II
Meiosis I completed
Mitotic division,producing large numbersof spermatogonia
Sperm cells
Acrosome
NucleusMitochondria
Neck
TailPlasma membrane
Head Midpiece
2n
2n
n n
nnnn
n n n n
Differentiation andOnset of meiosis I
Figure 46.12 Human Spermatogenesis
- Seminiferous tubules – produce sperm- Leydig cells – secrete testosterone &
other androgens- Sertoli cells – provide nutrition for
spermatids so they can mature- Takes 65 – 75 days to make sperm- 20 days to travel epididymis where
they mature & are stored
7. What happens after ejaculation?- Prostaglandins in semen thin mucus as the opening of the uterus & stimulate uterine contractions which help semen
move up uterus- Semen (slightly alkaline) neutralizes vagina (slightly acidic)
- Protects sperm & increases motility- Initially sperm are coagulated & become liquified so sperm can swim
8. How does viagra work?- Promotes the action of nitric oxide (NO) which enhances relaxation of smooth muscle in blood vessels of penis so blood
can enter erectile tissue9. What does the female reproductive anatomy look like?10. How are “eggs” made?
- Oogenesis 11. How are sperm made?
- Spermatogenesis12. What are the differences between spermatogenesis & oogenesis?
- Unequal cytokinesis in oogenesis produces 1 haploid ovum (& 2 polar bodies) & not 4 haploid sperm- Spermatogenesis mitosis occurs throughout life but ovary has all its follicles at birth- Oogenesis has long resting periods but spermatogenesis is uninterrupted & continuous
13. How do hormones control the menstrual cycle?
Figure 46.13 The reproductive cycle of the human femaleControl by hypothalamus Inhibited by combination of
estrogen and progesterone
Stimulated by high levelsof estrogen
Inhibited by low levels ofestrogen
Hypothalamus
Anterior pituitary
GnRH
FSH LH
Pituitary gonadotropinsin blood
LH
FSHFSH and LH stimulatefollicle to grow
LH surge triggersovulation
Ovarian cycle
Growing follicle Maturefollicle
Corpusluteum
Degenerating corpus luteum
Estrogen secretedby growing follicle inincreasing amounts
Progesterone andestrogen secretedby corpus luteum
Follicular phase Luteal phaseOvulation
Ovarian hormonesin blood
Peak causes LH surge
Estrogen Progesterone
Estrogen levelvery low
Progesterone and estro-gen promote thickeningof endometrium
Uterine (menstrual) cycle
Endometrium
Menstrual flow phase Proliferative phase Secretory phase
0 5 10 14 15 20 25 28
Day
s
1
(a)
(b)
(c)
(d)
(e)
3
6
7 8
4
5
2
9
10
GnRH – Gonadotropin Releasing Hormone- hypothalamus- stimulates release of FSH & LH
by anterior pituitaryFSH - Follicle Stimulating Hormone
- follicle grows & expresses LH receptorsLH - Lutenizing Hormone
- triggers ovulation (1 day after LH peak)- stimulates formation of corpus luteum
Estrogen – produced by growing follicle- stimulates GnRH release which triggers
more LH & FSH- estrogen peak causes LH peak
Progesterone – from corpus luteum- maintains thick endometrium in
preparation for embryo implantIf pregnancy does not occur the endometrium is shed….menstruation.Menopause – cessation of ovulation & menstru-
ation because ovaries lose responsive-ness to LH & FSH & estrogen decreases
7. What happens after ejaculation?8. How does viagra work?9. What does the female reproductive anatomy look like?10. How are “eggs” made?11. How are sperm made?12. What are the differences between spermatogenesis & oogenesis?13. How do hormones control the menstrual cycle?14. How do hormones control the male reproductive system?
- GnRH, FSH, & LH
Figure 46.14 Hormonal control of the testes
Stimuli from otherareas in the brain
Hypothalamus
GnRH from thehypothalamus reg-ulates FSH and LH
release from theanterior pituitary.
FSH acts on theSertoli cells of the
seminiferoustubules, promotingspermatogenesis.
LH stimulates the Leydig cells to maketestosterone, whichin turn stimulatessperm production.
Anteriorpituitary
Negativefeedback
Leydig cellsmake
testosteronePrimary andsecondary sexcharacteristics
Sertoli cells
Spermatogenesis Testis
7. What happens after ejaculation?8. How does viagra work?9. What does the female reproductive anatomy look like?10. How are “eggs” made?11. How are sperm made?12. What are the differences between spermatogenesis & oogenesis?13. How do hormones control the menstrual cycle?14. How do hormones control the male reproductive system?
- GnRH, FSH, & LH15. What is detected in pregnancy tests?
- HCG – human chorionic gonadotropin- Mimics LH which keeps corpus luteum secreting estrogen & progesterone- Endometrium stays thick
16. What happens after fertilization?
Fig 46.15 Formation of the zygote and early post-fertilization events
Ovary
Uterus
Endometrium
From ovulation to implantationEndometrium Inner cell mass
Cavity
BlastocystTrophoblast
Ovulation releases asecondary oocyte, whichenters the oviduct.
1
The blastocyst implants in the endometriumabout 7 days after conception.
5
Cleavage continues. By the time the embryoreaches the uterus, it is a ball of cells.It floats in the uterus forseveral days, nourished byendometrial secretions. It becomes a blastocyst.
4
Fertilization occurs. A sperm enters the oocyte; meiosis of
the oocyte finishes; and the nuclei of the ovum and sperm
fuse, producing a zygote.
2
Cleavage (cell division)begins in the oviduct
as the embryo is movedtoward the uterus
by peristalsis and themovements of cilia.
3
(a)
Implantation of blastocyst(b)
Inner cell mass – develops into embryo & extra-embryonic membranesTrophoblast – outer layer of blastocyst that grows out & mingles with endometrium &
helps form the placentaPlacenta – disk shaped organ containing embryonic & maternal blood vessels
Figure 46.16 Placental circulation
Placenta
Umbilical cord
Chorionic villuscontaining fetalcapillaries
Maternal bloodpools
Uterus Fetal arterioleFetal venuleUmbilical cord
Maternal portionof placenta
Fetal portion ofplacenta (chorion)
Umbilical arteriesUmbilical vein
Maternalarteries
Maternalveins
As placenta forms, HCG levels decline & placenta secretes its own progesteroneFetal nutrients gained from maternal blood pools….no mixing of blood.
7. What happens after ejaculation?8. How does viagra work?9. What does the female reproductive anatomy look like?10. How are “eggs” made?11. How are sperm made?12. What are the differences between spermatogenesis & oogenesis?13. How do hormones control the menstrual cycle?14. How do hormones control the male reproductive system?
- GnRH, FSH, & LH15. What is detected in pregnancy tests?
- HCG – human chorionic gonadotropin- Mimics LH which keeps corpus luteum secreting estrogen & progesterone- Endometrium stays thick
16. What happens after fertilization?17. How do hormones regulate parturition, aka child birth?
Figure 46.18 A model for the induction of labor
Estrogen Oxytocin
fromovaries
from fetusand mother'sposterior pituitary
Induces oxytocinreceptors on uterus
Stimulates uterusto contract
Stimulatesplacenta to make
Prostaglandins
Stimulate morecontractions
of uterus
Pos
itive
fee
dbac
k
Figure 46.19 The three stages of labor
PlacentaUmbilicalcordUterusCervix
Dilation of the cervix
Expulsion: delivery of the infant
UterusPlacenta(detaching)
Umbilicalcord
Delivery of the placenta
1
2
3
7. What happens after ejaculation?8. How does viagra work?9. What does the female reproductive anatomy look like?10. How are “eggs” made?11. How are sperm made?12. What are the differences between spermatogenesis & oogenesis?13. How do hormones control the menstrual cycle?14. How do hormones control the male reproductive system?
- GnRH, FSH, & LH15. What is detected in pregnancy tests?
- HCG – human chorionic gonadotropin- Mimics LH which keeps corpus luteum secreting estrogen & progesterone- Endometrium stays thick
16. What happens after fertilization?17. How do hormones regulate parturition, aka child birth?18. How does contraception work?
Figure 46.20 Mechanisms of some contraceptive methodsMale Female
Method Event Event Method
Production ofviable sperm
Production ofviable oocytes
VasectomyCombinationbirth control pill (or injection,patch, orvaginal ring)Sperm transport
down maleduct system
Ovulation
Abstinence
Condom
Coitusinterruptus(very highfailure rate)
Spermdepositedin vagina
Capture of theoocyte by the
oviduct
Abstinence
Tubal ligation
Spermicides;diaphragm;cervical cap;progestin alone(minipill, implant,or injection)
Sperm movementthrough female
reproductivetract
Transportof oocyte in
oviduct
Meeting of sperm and oocytein oviduct
Morning-after pill (MAP)Union of sperm and egg
Implantation of blastocyst in properly prepared
endometrium
Birth
Progestin alone
Birth control pills – estrogen & progesterone combo- prevents ovulation by decreasing the release
of GnRH which inhibits FSH & LH
Morning after pill – higher doses of estrogen & progesterone- prevents fertilization or implantation