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Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
PowerPoint TextEdit Art Slides for Biology, Seventh Edition
Neil Campbell and Jane Reece
Chapter 46Chapter 46
Animal Reproduction
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Figure 46.2 Asexual reproduction of a sea anemone (Anthopleura elegantissima)
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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.
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Figure 46.1 Earthworms mating
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Figure 46.5 External fertilization
Eggs
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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
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Vagina
Uterus
Cervix
OvariesOviduct
Uterine wallEndometrium
Follicles
Corpus luteum
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Figure 46.13b Oogenesis
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Figure 46.9x Ovary (left) and follicle (right)
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Figure 46.10 Reproductive anatomy of the human male
Erectile tissueof penis
Prostate gland
(Urinarybladder)
Bulbourethral gland
Vas deferensEpididymisTestis
Seminalvesicle(behind bladder)
Urethra
Scrotum
Glans penis
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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
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
Activity
• Work in groups to tell me about the travel of a group of sperm to see the legendary follicle
• Each member of your group will need to choose a role from below:
• Leader, Reporter, Recorder, Noise monitor
• Start out in the seminiferous tubules and work your way to the follicle
• Be sure to include structure and function
• This is a G rated classroom
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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
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Figure 46.12 Structure of a human sperm cell
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Figure 46.11 Human Oogenesis
Ovary
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
nnSecondpolarbody
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Figure 46.13 The reproductive cycle of the human femaleControl by hypothalamus Inhibited by combination of
estrogen and progesteroneStimulated by high levelsof estrogenInhibited 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
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Activity
• Work in pairs to compare the timing of the menstrual and ovarian cycles
• Answer:
– “Why does it make sense that each phase occurs when it does?”
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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
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Figure 46.15 Formation of the zygote and early postfertilization 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)
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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
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Figure 46.17 Human fetal development
5 weeks. Limb buds, eyes, the heart, the liver, and rudiments of all other organs have started to develop in the embryo, which is only about 1 cm long.
(a) 14 weeks. Growth and development of the offspring, now called a fetus, continue during the second trimester. This fetus is about 6 cm long.
(b) 20 weeks. By the end of the second trimester (at 24 weeks), the fetus grows to about 30 cm in length.
(c)
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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
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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
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Figure 46.20 Mechanisms of some contraceptive methodsMale Female
Method Event Event Method
Production ofviable sperm
Production ofviable oocytes
Vasectomy Combinationbirth 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
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Figure 46.21 Ultrasound image
Head
Body
Head
Body
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46.21 Ultrasound Of Fetus 1
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46.21 Ultrasound Of Fetus 2