Human Biology

Instructor: Steven Clark            Clark Community College    Email: sclark@clark.edu

The following reading assignment will be due June 10.  Reading assignments are not accepted one minute late.

Reading Homework

Chapter 20 page 430-438 NOTE: Figure 20.6 in my book is incorrect.  If the top cell on the right has a large pink chromosome (it is X shaped with a gold dot) with a small pink chromosome, it is wrong.  It should be the large pink paired with the large blue.  If your book is wrong, ignore figure 20.6 entirely.

1.      If you were Steve, would you have your DNA tested as Dan did?  Explain.

2.      In order to understand chapter 20, you will need to know a little about how a sperm cell and an egg cell are made.  That process is called meiosis.  It is the subject of chapter 19.  It is also displayed on this meiosis website.  (I've put the same link on my Human Biology page and titled it "Meiosis Review).  Don't worry about all the vocabulary.  I want you to understand how a sperm cell and an egg cell carry DNA information from dad or mom.  Were you able to watch the animation?

3.      Give an example of an allele that you have (remember, I want an example not a definition).

4.      Brown eyes are usually dominant to non-brown.  Considering your eyes and your parents' eyes, do you think your eye color gene is homozygous or heterozygous.  Explain your thinking.

5.      Give two examples of gametes (there are only two examples possible).

6.      Do you understand figure 20.3?

7.      After you’ve finished reading page 437, use the internet to find a human codominant trait other than blood type [Note—I’ll accept an animal co-dominant trait but I’d greatly prefer human].  What did you find?

8.      What would you like me to make clearer in lecture?

Next Reading due June 12 

Chapter 20 page 438-end 

1. After you read past figure 20.13, use the internet to find a human trait that exhibits pleiotropy or a trait that is recessive.  Find traits that weren't already mentioned in the text.  What did you find?
2. Page 440 says, “Genes on the same chromosome are usually inherited together.”  Why wouldn’t genes on the same chromosome ALWAYS be inherited together?  Explain.
3. Do you understand why some genes are linked to the Y or X chromosomes (i.e. sex linked)?
4. Suppose a girl had one recessive gene for Duchenne's syndrome.  Suppose a boy also had a recessive gene for Duchenne's syndrome.  The boy will get the disease but the girl won't.  Explain. 
5. Ask and answer a question from the section that discusses "Breaks in Chromosomes . . ."
6. Answer the "Stop and Think" question related to blood type on page 438.
7. What did you find interesting in the gene testing section?
8. How is PKU prevented?
9. Take the online chapter quiz.  How did you do?
10. What can I make more clear in lecture?