Campbell Essential Biology with Physiology

Eric J. Simon, Jean L. Dickey, Jane B. Reece

Chapter 26

Reproduction and Development - all with Video Answers

Educators

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Chapter Questions

Problem 1

Some animals, such as rotifers and aphids, are able to alternate between sexual and asexual reproduction. Under what conditions might it be advantageous to reproduce asexually? Sexually?

Nicole Hewett

Nicole Hewett

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Problem 2

A fertility specialist determines that a patient is producing a normal amount of sperm, but the semen does not contain enough of the fluids needed to nourish the sperm. Which male reproductive system anatomical structures are most likely responsible for this problem?

Krista Holliday

Krista Holliday

Numerade Educator

Problem 3

Match each reproductive structure with its description:
a. uterus
b. vas deferens
c. oviduct
d. ovary
e. endometrium
f. testis
1. female gonad
2. site of spermatogenesis
3. site of fertilization
4. site of pregnancy
5. lining of uterus
6. sperm duct

Krista Holliday

Krista Holliday

Numerade Educator

Problem 4

A woman has had several miscarriages. Her doctor suspects that a hormonal insufficiency has been causing the lining of the uterus to break down as it does during menstruation, terminating her pregnancies. Treatment with which of the following might help her remain pregnant?
a. oxytocin
b. HCG
c. follicle-stimulating hormone
d. prolactin

Prashant Bana

Numerade Educator

Problem 5

Why is it important that the hormones $F S H$ and $L H$ are inhibited after ovulation has occurred in the female cycle? Which female hormones inhibit $FSH$ and $LH$?

Sage Copling

Numerade Educator

Problem 6

What advantage do abstinence and condoms have over other forms of contraception?

Krista Holliday

Krista Holliday

Numerade Educator

Problem 7

How does a zygote differ from a mature egg?
a. A zygote has more chromosomes.
b. A zygote is smaller.
c. A zygote consists of more than one cell.
d. A zygote is much larger.

Krista Holliday

Krista Holliday

Numerade Educator

Problem 8

During what stage of development do layers of cells start to become different from one another?
a. fertilization
b. cleavage
c. gastrulation
d. birth

Krista Holliday

Krista Holliday

Numerade Educator

Problem 9

A pregnant woman is two weeks past her due date, and the doctor decides to induce her labor. The natural hormone that would be needed is _____.

Krista Holliday

Krista Holliday

Numerade Educator

Problem 10

The procedure that creates a "test-tube baby" is _____. What does this term literally mean?

Ajay Singhal

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Problem 11

For each statement, identify which major theme is evident (the relationship of structure to function, information flow, pathways that transform energy and matter, interactions within biological systems, or evolution) and explain how the statement relates to the theme. If necessary, review the themes (see Chapter 1 ) and review the examples highlighted in blue in this chapter.
The shape of a sperm provides insight into its role as the male gamete.

Raeann Mettler

Numerade Educator

Problem 12

For each statement, identify which major theme is evident (the relationship of structure to function, information flow, pathways that transform energy and matter, interactions within biological systems, or evolution) and explain how the statement relates to the theme. If necessary, review the themes (see Chapter 1 ) and review the examples highlighted in blue in this chapter.
The timing of menstruation and ovulation depends upon the coordination among the brain and several hormones.

Shiksha Dutta

Numerade Educator

Problem 13

For each statement, identify which major theme is evident (the relationship of structure to function, information flow, pathways that transform energy and matter, interactions within biological systems, or evolution) and explain how the statement relates to the theme. If necessary, review the themes (see Chapter 1 ) and review the examples highlighted in blue in this chapter.
By increasing genetic variability, sexual reproduction can increase the range of traits within a population upon which natural selection can act.

Bryan Lynn

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Problem 14

A typical egg cell survives about 24 hours, but some may survive up to 48 hours. A typical sperm survives 48 hours, but some may live up to 5 days. Assume that a female ovulates on day 14 of her cycle. How many days prior to ovulation and after ovulation is there a chance for pregnancy to occur? What is the total fertility window for this female?

Courtney Burson

Courtney Burson

Numerade Educator

Problem 15

A physician is trying to determine the cause of a male patient's infertility. Based on what you know about the male reproductive system, what would be the most logical things to test for?

Sage Copling

Numerade Educator

Problem 16

How effective are condoms at preventing the spread of HIV? Although this question is obviously very important to public health, it is difficult to study for many reasons: Animal models can't be used because HIV infects only humans, researchers cannot perform controlled studies, and research subjects may be hard to identify. A 2007 study was able to overcome some of these issues by studying HIV-negative partners of HIV-positive individuals. Such couples were divided into those who reported always using condoms and those who reported never doing so. The "always" group was found to have an HIV transmission rate of 1.1 new infections per 100 person-years. The "never" group had an HIV transmission rate of 5.8 infections per 100 person-years. What does it mean for the data to be reported in "person-years" and why is this important? What would be wrong about simply comparing the number of people who became infected in each group?

Ali Crampton

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Problem 17

New technology enables doctors to save a small percentage of babies born 16 weeks prematurely. A baby born this early weighs just over 1 pound and faces months in an intensive-care nursery. The cost of caring for the infant may be hundreds of thousands of dollars. Some people wonder whether such a huge technological and personnel investment should be devoted to such a small number of babies. They feel that limited resources might be better directed at providing prenatal care that could prevent many premature births. What do you think? In what ways should cost influence medical decisions?

Nick Johnson

Numerade Educator

Problem 18

Some infertile couples hire a surrogate mother to have their biological child. When couples enter into an agreement with a surrogate mother, all parties sign a contract. But there have been cases where a surrogate mother signed a contract but then decided not to give up the baby to the couple who hired her. Do you think a surrogate mother should have the right to change her mind and keep the baby, even though it is not genetically hers? In some cases, the surrogate will also donate her eggs to be fertilized by the male's sperm, making the baby genetically hers. Should she have a right to change her mind after she has signed a contract and the baby is born? How should judges decide these cases? Can you suggest any laws or regulations for such situations?

Josee Pacheco

Numerade Educator

Problem 19

When a couple uses in vitro fertilization to produce a baby, they are faced with some novel choices. Typically, more embryos are produced than will be used during any one procedure. Thus, a subset of prepared embryos has to be chosen for implantation. How should parents decide which embryos to use? Should they have the right to choose embryos based on the presence or absence of disease-causing genes? What about the sex of the embryo? Should parents be able to choose embryos for implantation based on any criteria? How would you distinguish acceptable criteria from unacceptable ones? Do you think such options should be legislated?

Josee Pacheco

Numerade Educator