Unit A Reproduction

Use What You’ve Learned
18. List at least three differences between the male
and female reproductive systems.
19. Explain the difference between ovulation and
implantation.
20. The endometrium is important during the
menstrual cycle and pregnancy. Explain the
role and fate of the endometrium.
21. Why do you think the circulatory system is the
first to function in a developing human embryo?
22. Why are scientists interested in stem cell research?
23. Draw diagrams to show the difference between
identical twins and fraternal twins.
24. (a) Does the karytoype in Figure 3 belong to a
female or a male?
(b) Explain how you can tell the gender.
Think Critically
27. The human embryo develops inside a sac filled
with amniotic fluid. What is the purpose of
this fluid?
28. Human males produce millions of sperm each
day and release millions of sperm into the
female vagina during ejaculation. Females only
release one egg at a time. Explain this difference
in the number of gametes released.
29. During the second trimester, the fetus swallows
amniotic fluid and urinates. If the fetus is
getting its nutrition from the mother through
the umbilical cord, what is the purpose of
swallowing the fluid?
30. Some references list 280 days as the length of a
human pregnancy, while others list 266 days.
Both are considered to be correct. How might
this difference be explained?
31. Many multiple births result from using artificial
reproductive technologies. Explain why these
multiple births occur.
32. Home pregnancy test kits are very common. Use
the Internet and other sources to research how
they work and how reliable they are.
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Figure 3
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Reflect on Your Learning
33. Reproductive technologies often involve
complicated procedures that are expensive and
may not be successful. Why do you think many
parents choose these invasive methods instead
of adopting a baby?
34. Did the discussion about hiring surrogate
mothers change your opinion about the use of
surrogate mothers? Explain why or why not.
25. Explain how nondisjunction can cause
disorders. Use examples.
26. List three prenatal diagnostic procedures and
the disorder or condition that the procedure
can diagnose.
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Chapter 4 Review 143