Chapter 46
Animal Reproduction
Teaching Objectives
Overview of Animal Reproduction
1. Distinguish between asexual and sexual reproduction.
2. List and describe four mechanisms of asexual reproduction.
3. Describe several adaptive advantages of asexual reproduction. Discuss the
conditions that may favor the occurrence of asexual reproduction.
4. Explain the advantages of periodic reproduction. Describe factors that may
control the timing of reproductive events.
5. Describe an example of an animal life cycle that alternates between
asexual and sexual reproduction.
6. Define parthenogenesis and describe the conditions that favor its
occurrence. Note examples of invertebrate and vertebrate species that use
this form of reproduction.
7. Explain how hermaphroditism may be advantageous in sessile or
burrowing animals that have difficulty encountering a member of the
opposite sex.
8. Distinguish between male-first and female-first sequential
hermaphroditism. Note the adaptive advantages of these reproductive
systems.
Mechanisms of Sexual Reproduction
9. Describe mechanisms that increase the probability that mature sperm will
encounter fertile eggs of the same species in organisms that use external
fertilization.
10. Explain the function of pheromones in mate attraction.
11. Compare reproductive systems using internal and external fertilization on
the basis of the relative number of zygotes and protection of the embryos.
12. List and describe various methods of egg and embryo protection.
13. Compare the reproductive systems of a polychaete worm, a parasitic
flatworm, an insect, a common nonmammalian vertebrate, and a mammal.
Mammalian Reproduction
14. Using a diagram, identify and give the function of each component of the
reproductive system of the human male.
15. Using a diagram, identify and give the function of each component of the
reproductive system of the human female.
16. Describe the two physiological reactions common to sexual arousal in both
sexes.
17. Describe the four phases of the sexual response cycle.
18. Compare menstrual cycles and estrous cycles.
19. Describe the stages of the human female reproductive cycle.
20. Explain how the uterine cycle and ovarian cycle are synchronized in female
mammals. Note in detail the functions of the hormones involved.
21. Describe human oogenesis.
22. Describe spermatogenesis and the structure and function of mature sperm.
23. Describe three major differences between oogenesis and
spermatogenesis.
24. Describe human menopause. Describe a possible evolutionary explanation
for human menopause.
25. Describe the influence of androgens on primary and secondary sex
characteristics and behavior.
26. Compare the patterns of hormone secretion and reproductive events in
male and female mammals.
27. Define conception, gestation, and parturition.
28. Compare the length of pregnancies in humans, rodents, dogs, cows, and
elephants.
29. Describe the changes that occur in the mother and the developing embryo
during each trimester of a human pregnancy.
30. Explain the role of embryonic hormones during the first few months of
pregnancy.
31. Describe the stages of parturition.
32. Describe the control of lactation.
33. Describe mechanisms that may help prevent the mother’s immune system
from rejecting the developing embryo.
34. List the various methods of contraception and explain how each works.
35. Describe techniques that allow us to learn about the health and genetics of
a fetus.
36. Explain how and when in vitro fertilization, zygote intrafallopian transfer,
and gamete intrafallopian transfer may be used.
Student Misconceptions
1. Explain to your students the fundamental difference between sex and
reproduction. Sex is the creation of genetically novel individuals, with a
genetic contribution from two parents. Reproduction is the creation of new
individuals. Thus, sexual reproduction is the creation of new, genetically
novel individuals with two parents. Asexual reproduction is the creation of
new individuals whose genes all come from a single parent.
2. Clarify for your students the basic biological difference between male and
female. A male is an individual who produces many small, motile gametes;
a female is an individual who produces few large, nonmotile gametes.
3. In discussing animal reproduction, explain to your students the role of
meiosis in producing haploid animal gametes, but also point out that
meiosis is not a sexual process in the other multicellular kingdoms. In
plants and fungi, meiosis is the process for production of haploid, asexual
spores.
Chapter Guide to Teaching Resources
Overview: Doubling up for sexual reproduction
Concept 46.1 Both asexual and sexual reproduction occur
in the animal kingdom
Transparency
Figure 46.3 Sexual behavior in parthenogenetic lizards
Instructor and Student Media Resources
Video: Hydra budding
Video: Hydra releasing sperm
Concept 46.2 Fertilization depends on mechanisms that help
sperm meet eggs of the same species
Transparencies
Figure 46.7 Reproductive anatomy of a parasitic flatworm
Figure 46.8 Insect reproductive anatomy
Concept 46.3 Reproductive organs produce and transport
gametes: focus on humans
Transparencies
Figure 46.9 Reproductive anatomy of the human female (part 1)
Figure 46.9 Reproductive anatomy of the human female (part 2)
Figure 46.10 Reproductive anatomy of the human male (part 1)
Figure 46.10 Reproductive anatomy of the human male (part 2)
Student Media Resources
Activity: Reproductive system of the human female
Activity: Reproductive system of the human male
Investigation: What might obstruct the male urethra?
Concept 46.4 In humans and other mammals, a complex
interplay of hormones regulates gametogenesis
Transparencies
Figure 46.11 Human oogenesis
Figure 46.12 Human spermatogenesis
Figure 46.13 The reproductive cycle of the human female
Figure 46.14 Hormonal control of the testes
Concept 46.5 In humans and other placental mammals,
an embryo grows into a newborn in the mother’s uterus
Transparencies
Figure 46.15 Formation of the zygote and early postfertilization events
Figure 46.16 Placental circulation
Figure 46.18 A model for the induction of labor
Figure 46.19 The three stages of labor
Figure 46.20 Mechanisms of some contraceptive methods
Instructor and Student Media Resources
Video: Ultrasound of human fetus 1
Video: Ultrasound of human fetus 2
Review
Page 986
The distribution of care behavior
For additional resources such as digital images and lecture outlines, go
to the Campbell Media Manager or the Instructor Resources section of
www.campbellbiology.com.
Key Terms
acrosome
asexual reproduction
assisted reproductive technology (ART)
baculum
barrier method
Bartholin’s glands
birth control pills
blastocyst
budding
bulbourethral gland
cervix
cleavage
clitoris
cloaca
coitus
conception
condom
contraception
corpus luteum
diaphragm
egg
ejaculation
ejaculatory duct
endometrium
epididymis
estrous cycle
estrus
external fertilization
fertilization
fetus
fission
follicle
follicular phase
fragmentation
gamete
gametogenesis
gestation
glans penis
gonads
hermaphroditism
human chorionic gonadotropin (HCG)
hymen
in vitro fertilization
internal fertilization
labia majora
labia minora
labor
lactation
Leydig cell
luteal phase
mammary glands
menopause
menstrual cycle
menstrual flow phase
menstruation
myotonia
natural family planning
oogenesis
oogonia
organogenesis
orgasm
ovarian cycle
ovary
oviduct
ovulation
ovum
parthenogenesis
parturition
penis
pheromone
placenta
pregnancy
prepuce
primary oocyte
proliferative phase
prostate gland
regeneration
rhythm method
scrotum
secondary oocyte
secretory phase
semen
seminal vesicle
seminiferous tubule
sequential hermaphroditism
sexual reproduction
sperm
spermatheca
spermatogenesis
spermatogonia
testis
trimester
trophoblast
tubal ligation
urethra
uterine cycle
uterus
vagina
vas deferens
vasectomy
vasocongestion
vestibule
vulva
zygote
Chapter 46 Animal Reproduction
## Instructor’s Guide for Campbell/Reece Biology, Seventh Edition
Word Roots
a- 5 not, without (asexual reproduction: a type of reproduction involving only
one parent that produces genetically identical offspring)
acro- 5 tip; -soma 5 body (acrosome: an organelle at the tip of a sperm cell
that helps the sperm penetrate the egg)
bacul- 5 a rod (baculum: a bone that is contained in, and helps stiffen, the
penis of rodents, raccoons, walruses, and several other mammals)
blasto- 5 produce; -cyst 5 sac, bladder (blastocyst: a hollow ball of cells
produced one week after fertilization in humans)
coit- 5 a coming together (coitus: the insertion of a penis into a vagina, also
called sexual intercourse)
contra- 5 against (contraception: the prevention of pregnancy)
-ectomy 5 cut out (vasectomy: the cutting of each vas deferens to prevent
sperm from entering the urethra)
endo- 5 inside (endometrium: the inner lining of the uterus, which is richly
supplied with blood vessels)
epi- 5 above, over (epididymis: a coiled tubule located adjacent to the testes
where sperm are stored)
labi- 5 lip; major- = larger (labia majora: a pair of thick, fatty ridges that
enclose and protect the labia minora and vestibule)
lact- 5 milk (lactation: the production of milk)
menstru- 5 month (menstruation: the shedding of portions of the endometrium
during a menstrual cycle)
minor- 5 smaller (labia minora: a pair of slender skin folds that enclose and
protect the vestibule)
myo- 5 muscle (myotonia: increased muscle tension)
oo- 5 egg; -genesis 5 producing (oogenesis: the process in the ovary that
results in the production of female gametes)
partheno- 5 a virgin (parthenogenesis: a type of reproduction in which females
produce offspring from unfertilized eggs)
partur- 5 giving birth (parturition: the expulsion of a baby from the mother, also
called birth)
-theca 5 a cup, case (spermatheca: a sac in the female reproductive system
where sperm are stored)
tri- 5 three (trimester: a three-month period)
vasa- 5 a vessel (vasocongestion: the filling of a tissue with blood caused by
increased blood flow through the arteries of that tissue)
## Instructor’s Guide for Campbell/Reece Biology, Seventh EditionChapter 46 Animal Reproduction ## Instructor’s Guide for
Campbell/Reece Biology, Seventh Editionabortion