Biology, Seventh Edition
Solomon • Berg • Martin
Chapter 48
Reproduction
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Asexual reproduction
• A single parent endows its offspring
with genes identical to its own
–Energy efficient
–Most successful in a stable
environment
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Means of asexual reproduction
• Budding
–Part of the parent’s body grows and
separates from the rest of the body
• Fragmentation
–The parent’s body breaks into pieces
–Each piece can grow into a new animal
• Parthenogenesis
–An unfertilized egg develops into an
adult
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Asexual
reproduction
by budding
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Sexual reproduction
• Offspring produced by fusion of two
gametes
–Ovum
–Sperm
• A fertilized egg (zygote) forms
• Promotes genetic variety and is
adaptive in an unstable
environment
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• External fertilization
• Mating partners typically release
eggs into the water simultaneously
• Internal fertilization
• Male delivers sperm into the
female’s body
• Hermaphroditism
• Single individual produces eggs
and sperm
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human male reproductive system
• Testes
–Housed in the scrotum
–Contain the seminiferous tubules,
where sperm production takes place
–Interstitial cells secrete testosterone
–Sertoli cells produce signaling
molecules and a fluid that nourishes
sperm cells
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human male reproductive
system, cont.
• Sperm
–Stored in the epididymis and vas
deferens
–During ejaculation, sperm pass from
the vas deferens to the ejaculatory
duct and into the urethra
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human male reproductive
system, cont.
• Penis
–Three columns of erectile tissue
–Two cavernous bodies
–One spongy body that surrounds the
urethra
• Erectile tissue becomes engorged
with blood and causes erection
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Male reproductive
system
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Spermatogenesis
• Takes place in the seminiferous
tubules
• Spermatogonia divide by mitosis
• Head of a sperm consists of the
nucleus and an acrosome,
containing enzymes that help
penetrate the egg
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Spermatogenesis in the seminiferous tubules
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Spermatogenesis
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Sperm pass in sequence through
• Seminiferous tubes of the testes
• Epididymis
• Vas deferens
• Ejaculatory duct
• Urethra
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Structure of
a
mature sperm
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Endocrine regulation of
reproduction in the human male
• Testosterone establishes and
maintains
–Primary sex characteristics
–Secondary sex characteristics
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Internal
structure of
the penis
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Endocrine regulation of reproduction
involves the
• Hypothalamus
–GnRH
• Pituitary gland
–FSH and LH
• Testes
–Testosterone
–ABP and inhibin
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
Principal male reproductive hormones
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Regulation of
reproduction in
the male
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human female reproductive
system
• Ovaries
–Produce gametes
–Steroid hormones estrogen and
progesterone
• Fertilization takes place in the
oviducts
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Female
reproductive
system
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human female reproductive
system, cont.
• Uterus
–Incubator for the embryo
–Endometrium thickens each month
–Cervix extends into the vagina
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human female reproductive
system, cont.
• Vagina
–Lower part of the birth canal
–Vulva includes the labia majora, labia
minora, vestibule, clitoris, and mons
pubis
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Female
reproductive
system,
anterior view
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human female reproductive
system, cont.
• Breasts
–Function in lactation
–Prolactin stimulates milk production
–Oxytocin stimulates milk ejection from
the alveoli into the ducts
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Development of a human ovum
• Oogenesis takes places in the
ovaries
• Oogonia differentiate into primary
oocytes
–Primary oocyte and granulosa cells
make up a follicle
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Oogenesis
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Development of a human ovum,
cont.
• As the follicle grows
–Connective tissue cells form a layer of
theca cells
–Primary oocyte undergoes meitosis,
giving rise to a secondary oocyte and
a polar body
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Development of
follicles in the
ovary
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Development of a human ovum,
cont.
• During ovulation
–The secondary oocyte is ejected and
enters an oviduct to be fertilized
–The part of the remaining follicle
develops into a corpus luteum
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Endocrine regulation of
reproduction
• Preovulatory phase
–GnRH stimulates the pituitary to
secrete FSH and LH
–Estrogen stimulates endometrium
development
–LH stimulates final maturation of the
follicle and ovulation
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Endocrine regulation of
reproduction, cont.
• Postovulatory phase
–LH promotes development of the
corpus luteum
–The corpus luteum secretes
progesterone and estrogen
–If fertilization does not occur, the
corpus luteum degenerates, hormone
levels fall, and menstruation occurs
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
Principal female reproductive hormones
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Feedback mechanisms in endocrine regulation of
female reproduction
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Physiological changes that occur
during sexual response
• Sexual excitement
• Plateau
• Orgasm
• Resolution
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human fertilization
• Fusion of secondary oocyte and
sperm to form a zygote
• Embryo implants in the uterus
• hCG is the hormone that maintains
the corpus luteum
• Estrogen and progesterone
–Secreted by corpus luteum (first
trimester) and then by placenta
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Fertilization
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Events following fertilization
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Human birth process
• Several hormones, including
estrogen, oxytocin, and
prostaglandins regulate parturition
• Labor
–Divided into three stages
–The baby is delivered during the
second stage
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Contraception
• Hormonal methods, such as oral
contraceptives
• Intrauterine devices
• Condoms and contraceptive
diaphragms
• Sterilization (vasectomy or tubal
ligation)
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Sterilization
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Abortions
• Spontaneous miscarriages occur
without intervention
• Induced abortions
–Therapeutic performed to maintain the
mother’s health, as birth control, or
when the embryo is thought to be
grossly abnormal
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Biology, Seventh Edition
CHAPTER 48 Reproduction
• Common sexually transmitted
diseases (STDs)
• Chlamydia
• Gonorrhea
• Syphilis
• Pelvic inflammatory disease (PID)
• Genital herpes
• HIV
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
• Endocrine regulation of reproduction
involves the
• Hypothalamus
–GnRH
• Pituitary gland
–FSH and LH
• Testes
–Testosterone
–ABP and inhibin
Copyright © 2005 Brooks/Cole — Thomson Learning
Biology, Seventh Edition
CHAPTER 48 Reproduction
Some types of endocrine signaling
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Biology, Seventh Edition
CHAPTER 48 Reproduction
Major
chemical
groups of
hormones
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