SCIENCE

Before reading

1.    Everybody has the same number and the same types of genes. But each of those genes can vary somewhat. List some ways those variations can show up in the differing appearances of you and your friends.

During reading

1.    How many genes do we have?

2.    What does RNAi turn off?

3.    What do A, T, C and G stand for?

4.    Where might you find uracil?

5.    What does “express” mean when used in discussing genes.

6.    Explain what Argonautes do.

7.    When Argonautes cut mRNA, what is lost?

8.    How can viruses help deliver RNAi triggers?

9.    List two ways, besides using viruses, that scientists might get RNAi triggers into cells.

10. Why do mutated genes sometimes cause problems?

11. Explain why cancer’s triggering the off switch on an immune cell could be bad for your health.

After reading

1.    Why do experts liken RNAi to fiddling with the fuses or circuit breakers in your house?

2.    Explain how RNAi might one day lead to a cure for Huntington’s disease.

MATHEMATICS

1.       Imagine adenine (A) makes up 20 percent of the bases in a DNA sample. If so, then what percentage of the bases in that sample must be guanine (G)?