Name:       Sec:

Chapter 5: Chromosomes and Inheritance

Module 5.6. Gametes have half as many chromosomes as body cells.

1.       is the process that results from the union of gametes from two different parents.

2. A skin cell is to a somate as a(n) ________ is to a gamete.

A) |_| embryo

B) |_| zygote

C) |_| brain cell

D) |_| egg

3. Determine whether each of the following cells is haploid or diploid:

A) An egg

B) A cell from your liver

C) A zygote

D) A sperm

E) A cell from your heart

4. A normal human egg or sperm has 23 chromosomes, which is exactly one half what a somate has. Briefly explain what would happen every generation if gametes were actually diploid.

5. _______contain the same genes at the same locations.

A) |_| Sex chromosomes

B) |_| Autosomes

C) |_| Gametes

D) |_| Homologous chromosomes

6. Are the two chromosomes shown here homologous? Briefly explain why or why not.

7. Can a karyotype be used to determine the gender of an individual? Briefly explain your answer.

Module 5.7. Meiosis produces gametes.

8.       is the type of cell division that produces gametes.

9. A similarity that meiosis shares with mitosis is which of the following:

A) |_| They both undergo chromosome duplication.

B) |_| They both have two rounds of cell division.

C) |_| They both occur in somatic cells.

D) |_| They both have only one round of cell division.

10. Fill in the following table (yes or no) contrasting mitosis and meiosis:

	Mitosis	Meiosis
Chromosomes duplicate prior to cell division
Chromosomes condense prior to division
How do chromosomes line up prior to cell division

11. Is the following cell in undergoing mitosis or meiosis. Assume the starting cell was diploid and had two pairs of chromosomes. Briefly explain your answer.

12. True for False; If false make a true statement: At the end of meiosis I, the two cells are both diploid.

13. At the end of meiosis II, there are ____ cells and they are all ____.

A) |_| four; diploid

B) |_| two; haploid

C) |_| four; haploid

D) |_| two; diploid

Module 5.8. Mitosis and meiosis have important similarities and differences.

14. Mitosis is to a somate as meisosis is to a(n)      .

15. Give an example of a cell in your body that undergoes mitosis. How many chromosomes does that cell have?

16. Mitosis creates ____, while meiosis creates ____:

A) |_| haploid gametes; diploid gametes

B) |_| diploid somates; diploid gametes

C) |_| haploid somates; haploid gametes

D) |_| diploid somates; haploid gametes

17. A cell biologist observes a cell under a microscope and determines that the cell contains nine chromosomes. Is this cell diploid or haploid? Briefly explain.

Module 5.9. Several processes produce genetic variation among sexually reproducing organisms.

18. The process of a sperm and egg uniting is called:

A) |_| crossing over

B) |_| independent assortment

C) |_| fertilization

D) |_| mitosis

19. Sexual reproduction produces a tremendous amount of diversity in organisms. List three ways in which this diversity is accomplished.

1.

2.

3.

20. Each homologous pair of chromosomes can line up in one of two orientations. This kind of alignment is known as      .

21. A biologist is studying cells from a new organism recently discovered in a rain forest. He determines that the somates contain a total of eight chromosomes. How many possible combinations of chromosomes could this organism produce as a result of independent assortment? Assume the organism reproduces sexually.

22. Explain why the term crossing over is accurate for the process it names.

23. Crossing over produces:

A) |_| hybrid chromosomes

B) |_| independent assortment

C) |_| random fertilization

D) |_| a zygote

24. Has the homologous pair of chromosomes in the following figure undergone crossing over? Explain your answer.

Module 5.10. Mistakes during meiosis can produce gametes with abnormal numbers of chromosomes.

25. The failure of chromosomes to separate properly is known as

26. True or False; If false, make a true statement: Nondisjunction always results in a zygote with the incorrect number of chromosomes.

27. A human zygote is created from a sperm that contained an extra chromosome 21. How many total chromosomes did the sperm contain? How many chromosomes does the zygote have?

28. Does the individual from the karyotype shown here have a normal number of chromosomes? If not, what syndrome does he or she have?

29. Complete the following table regarding sex chromosome abnormalities:

Sex chromosomes	Syndrome	Sex
	Klinefelter syndrome
XYY
		Female
XO

30. An individual is determined to have Jacob’s syndrome. Is it possible to determine which parent’s gamete had the incorrect number of chromosomes? If so, which one was it? Briefly explain your answer either way.