Reproduction

1. Chapter 27 Reproduction and Embryonic Development
PowerPoint Lectures for
Biology: Concepts & Connections, Sixth Edition
Campbell, Reece, Taylor, Simon, and Dickey
Copyright © 2009 Pearson Education, Inc.
Lecture by Richard L. Myers
Translated by Nabih A. Baeshen

2. ASEXUAL AND SEXUAL
REPRODUCTION
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3. 27.1 Asexual reproduction results in the generation of genetically
identical offspring
Asexual reproduction
– One parent produces genetically identical offspring
– Very rapid reproduction
– Can proceed via
– Budding /
– Fission /
– Fragmentation/regeneration
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Asexual reproduction of an aggregating sea
anemone (Anthopleura elegantissima) by fission

4. 27.2 Sexual reproduction results in the generation of genetically
unique offspring
Some animals exhibit hermaphroditism
– One individual with male and female reproductive
systems
– Easier to find a mate for animals less mobile or solitary
Hermaphroditic
earthworms mating
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5. 27.2 Sexual reproduction results in the generation of genetically
unique offspring
Sperm may be transferred to the female by
– External fertilization
– Many fish and amphibian species
– Eggs and sperm are discharged near each other
– Internal fertilization
– Some fish and amphibian species
– Nearly all terrestrial animals
– Sperm is deposited in or near the female
reproductive tract
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Frogs in an embrace that
triggers the release of
eggs and sperm

6. HUMAN REPRODUCTION
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7. 27.3 Reproductive anatomy of the human female
Both sexes in humans have
– A set of gonads where gametes are
produced
– Ducts for gamete transport
– Structures for copulation
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8. 27.3 Reproductive anatomy of the human female
Ovaries contain follicles that Nurture eggs and
Produce sex hormones
Oviducts convey eggs to the uterus where
embryos develop
The uterus opens into the vagina through the
The vagina
– Receives the penis during sexual intercourse
– Forms the birth canal
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9. Oviduct Ovaries
Follicles
Corpus luteum
Wall of uterus Uterus
Endometrium
(lining of uterus)
Vagina
Cervix
(“neck” of uterus
Front view of female reproductive anatomy (upper portion)

10. 27.4 Reproductive anatomy of the human male
Testes (singular testis) produce Sperm and Male
hormones
Epididymis stores sperm as they develop further
Several glands contribute to semen
– Seminal vesicles
– Prostate
– Bulbourethral
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11. Urinary
Bladder
Prostate gland
Bulbourethral gland
Seminal
Vesicle
(behind
Bladder)
Erectile tissue of penis
Urethra
Scrotum
Vas deferens
Epididymis
Testis Glans of
Penis
Front view of male reproductive anatomy

12. 27.4 Reproductive anatomy of the human male
SSppeerrmm pprroodduuccttiioonn
– Regulated by a negative feedback
system of hormones
– Involves the hypothalamus,
pituitary, and testes
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13. Hypothalamus
Anterior
Pituitary
Stimuli from other
areas in the brain
Releasing
Hormone
Negative feedback
FSH LH
Testis
Androgen
production
Sperm production Hormonal control of the testis

14. 27.5 The formation of sperm and egg requires meiosis
Spermatogenesis
– Occurs in seminiferous tubules
– Primary spermatocytes
– Formed by mitosis
– Divide by meiosis I to produce secondary
spermatocytes
– Secondary spermatocytes divide by meiosis II to
produce spermatids
– Round spermatids differentiate into elongate sperm
– Mature sperm released into seminiferous tubule
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15. Testis
Epididymis
Testis
Scrotum
Penis
Seminiferous
Tubule
Cross section of
seminiferous tubule

16. Diploid cell
Primary spermatocyte
(in prophase of Meiosis I)
Secondary spermatocyte
(haploid; double chromatids)
Developing sperm cells
(haploid; single chromatids)
Sperm cells
(haploid)
Center of seminiferous tubule

17. 2n
2n
Primary spermatocyte
(in prophase of Meiosis I)
Meiosis I completed
n n Secondary spermatocyte
(haploid; double chromatids)
Differentiation and
onset of Meiosis I
Diploid cell
n n n n
n n n n
Developing sperm cells
(haploid; single chromatids)
Differentiation
Sperm cells
(haploid)
Meiosis II

18. 27.5 The formation of sperm and egg requires meiosis
Oogenesis
– Begins before birth: diploid cells start meiosis and
stop
– Each month about one primary oocyte resumes
meiosis
– A secondary oocyte arrested at metaphase of
meiosis II is ovulated
– Meiosis of the ovum is completed after
fertilization
Copyright © 2009 Pearson Education, Inc.

19. 2n
2n
Differentiation
and onset of
Meiosis I
Diploid cell in embryo
Primary oocyte
Completion
of Meiosis I
and onset of
Corpus
First
n
luteum
Ovary
(arrested in prophase
of Meiosis I; present
at birth)
npolar body
n
Meiosis II
n
n
Entry of sperm
triggers completion
of Meiosis II
Second
polar body
Ovum
(haploid) Sperm
Ovulation Ruptured follicle
Growing
Follicle
Mature follicle
Secondary oocyte
(arrested at meta-phase
of Meiosis II;
released from ovary)
Oogenesis and the development of an ovarian follicle

20. 27.6 Hormones synchronize cyclic changes in the ovary
and uterus
Ovarian and menstrual cycles
– Occur about every 28 days
– Hypothalamus signals the anterior pituitary to
secrete follicle-stimulating hormone (FSH) and
leuteinizing hormone (LH), which trigger
– Growth of a follicle
– Ovulation
Copyright © 2009 Pearson Education, Inc.

22. 27.6 Hormones synchronize cyclic changes in the ovary and uterus
After ovulation, ovarian follicle becomes corpus
luteum
Corpus luteum secretes estrogen and
progesterone, which
– Stimulate the endometrium to thicken
– Prepare the uterus for implantation of the
embryo
– Inhibit hypothalamus, reducing FSH and LH
secretion
Copyright © 2009 Pearson Education, Inc.

23. 27.6 Hormones synchronize cyclic changes in the ovary and uterus
IIff eegggg iiss ffeerrttiilliizzeedd
– Developing embryo releases hormones(human chorionic
gonadotropin) that maintain the corpus luteum which
continue to secrete progesterone and estrogen
maintaining uterine lining to complete the pregnancy.
– Menstruation does not occur
IIff eegggg iiss nnoott ffeerrttiilliizzeedd
– Drop in LH shuts down corpus luteum and stop secreting
its hormones(progesterone and estrogen )
– Menstruation is triggered
– Hypothalamus and pituitary stimulate development of a
new follicle
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24. PRINCIPLES OF
EMBRYONIC DEVELOPMENT
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25. 27.9 Fertilization results in a zygote and triggers embryonic development
Embryonic development begins with fertilization
– The union of sperm and egg
– To form a diploid zygote
Sperm are adapted to reach and fertilize an egg
Streamlined shape moves more easily through
fluids
Many mitochondria provide ATP for tail movements
Head contains a haploid nucleus Tipped with an
acrosome containing penetrating enzymes
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26. Tail
Plasma membrane
Neck
Middle piece
Head
Mitochondrion
(spiral shape)
Nucleus
Acrosome
The structure of a human sperm cell

27. 27.9 Fertilization results in a zygote and triggers embryonic
development
Fertilization events
– Sperm squeeze past follicle cells
– Acrosomal enzymes pierce egg’s coat
– Sperm binds to vitelline layer
– Sperm and egg plasma membranes fuse
– Egg is stimulated to develop further
– Egg and sperm nuclei fuse(become diploid)
Copyright © 2009 Pearson Education, Inc.

28. The sperm squeezes
through cells left
over from the follicle
1 2
3
4
5
6
The sperm’s
acrosomal
enzymes digest the
egg’s jelly coat
Proteins on the
sperm head bind to
egg receptors The plasma membranes
of sperm and egg fuse
The sperm nucleus
enters the egg
cytoplasm
A fertilization
envelope
forms
Sperm
Nucleus
Acrosome
Plasma
membrane
Sperm
head
Acrosomal
enzymes
Sperm
nucleus
Receptor protein molecules
Plasma
membrane
Vitelline layer
ا
ط ا
Cytoplasm
Egg
nucleus
Jelly coat

29. ف ا
ا
Egg cell
The nuclei
of sperm and egg fuse
7
Zygote nucleus

30. 27.10 Cleavage produces a ball of cells from the zygote
Cleavage is a rapid series of cell
divisions
– More cells
– Embryo does not get larger
– Thus new cells are smaller in size
Copyright © 2009 Pearson Education, Inc.

31. 8 cells
4 cells
Zygote 2 cells
Blastula
(hollow ball) Cross section
of blastula
Blastocoel
Many cells
(solid ball)
Cleavage in a sea urchin

32. 27.11 Gastrulation produces a three-layered embryo
Gastrulation
– Cells migrate
– The basic body plan of three layers is established
– Ectoderm outside—becomes skin and nervous
systems
– Endoderm inside—becomes digestive tract
– Mesoderm in middle—muscle and bone
– A rudimentary digestive cavity forms
Copyright © 2009 Pearson Education, Inc.

33. Blastula
(end of cleavage)
Animal pole
Blastocoel
Vegetal pole
Gastrulation
(cell migration)
Blastocoel
Formation of a
simple digestive
shrinking
cavity
Blastopore
Ectoderm
Mesoderm
Gastrula
(end of gastrulation)
Simple Endoderm
digestive
cavity
Development of the frog gastrula

35. You should now be able to
1. Explain how fertility drugs have affected multiple births in the United States
2. 2. Compare the types of asexual and sexual reproduction
3. Describe the structures and functions of the male and female human reproductive
tracts
4. Describe and compare spermatogenesis and oogenesis
5. Describe the events of the menstrual cycle
6. Describe the nature of the most common STDs
7. Describe the most common forms ooff bbiirrtthh ccoonnttrrooll
8. Relate the structure of sperm to its roles in fertilization
9. Describe the processes of cleavage and gastrulation
10. Describe the functions of the four extraembryonic membranes
11 Describe the main changes that occur during each trimester of human
development
12. Describe the most common reproductive technologies
Copyright © 2009 Pearson Education, Inc.

36. Reproduction
ــــــــ ا ـــ ا

37. ــ
Angiosperms
ت ا ور Sporophyte :The Diploid Generation. .

38. #$ % ا
ا :ا ا د ا وزو ا
ا :ا أ دي ا Gametophyte: The Haploid Generation. .

39. د
( % ا وزو Pollen Grain: The Male ح :ا ا ا Gametophyte. .

40. + ,(
Embryo ا
ا : ا ا ا Sac: The Female Gametophyte. . ي./0 - Endosperm: ا
وم : وا ة دا ا ا Central Cell Within The
- %3 45

41. ( 43

42. /2 Embryo Sac Has Two Nuclei.
ن. ا/ 8
Pollination :Transfer Of Pollen From Anther
To Stigma.
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Double Fertilization: One Sperm Fertilizes
The Egg To Produce A Zygote, The Other
Fuses With The Central Cell Nuclei To
Produce 3n Endosperm.
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ج /C ى

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46. د ا
ا
Seed Dormancy: Embryo Growth And
Development Are Suspended.
.A ا A و /
H رة: ن ا
Two Cotyledons = Eudicot Seeds ن9+N
Single Cotyledon = Monocot Seeds ة( وا 4+N

47. Reproduction
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48. ــ
ا
ة: ا Fruit: Developed Ovary. . %9 O

49. . ا
Germination ت/2 Asexual Reproduction: One Parent
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50. $ 9 ا
ا : أ ا اذر ورا ً . Produces Genetically Identical Offspring.
Hermaphroditism: One Individual With
Male And Female Reproductive Systems.
. 4./ وأ 4

51. ذ

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53. N : 4$E ا
External Fertilization: Eggs And Sperm Are
Discharged Near Each Other.
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ا 8J
A ب

54. +
Internal Fertilization: Sperm Is Deposited
In Or Near The Female Reproductive Tract.
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55. H
Gonads: Where Gametes Are Produced. . ت ج ا 9/ ا ;9 X( : % ا
Ovaries: Contain Follicles That Nurture
Eggs And Produce Sex Hormones.
4Y ــ م + 9 ت وا I( =: ي 9G : O ا
.- ت ا /

56. ج ھ 9/ وا O ا
Testes (Singular Testis): Produce Sperm And
Male Hormones.
4 ت ا / اG ا L9 ): 43 دھ

57. [ ( E ا
رة . ت ا /

58. ھ
Epididymis: Stores Sperm As They Develop
Further
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59. ا

60. Reproduction
ــــــــ ا ـــ ا

61. ــ
Spermatogenesis: Formation Of Sperms. 4 / G A 4:
ا ات ا Oogenesis: Formation Of Ovum. O ا A 4:
Menstrual ا
Cycle 4

62. 8] ورة ا Menstruation ا
OG Corpus ا
ا Luteum

63. [^0 ; اا Endometrium ;(

64. 4/
Cleavage: Rapid Series ا
Of Cell Divisions. .: ھ ا ت ا 4E +/C A 4

65. 4 L[9 ا
: ھ ة ا و Gastrulation: Cells Migrate And Basic Body
40 4E ا ا -S ;9 IE

66. A9 ذو ا ث ط ت . Plan Of Three Layers Is Established.
+ I. ;