RNAi is a technique that silences genes by targeting them and degrading their mRNA. How can this technique be used in scientific laboratories?

A. RNAi has been used in laboratories to make bacteria more susceptible to antibiotics, but has limited application in eukaryotic cells.
B. RNAi is a powerful tool for degrading mRNA, but because it doesn't degrade other types of RNA, its use is limited.
C. RNAi is observed in nature, but it can't be used in laboratories.
D. RNAi allows scientists to turn off one gene specifically to study its effect
The enzyme DNA polymerase works only in the 5′ to 3′ direction. How does this affect the leading strand and the lagging strand?



The enzyme DNA polymerase works only in the 5′ to 3′ direction. How does this affect the leading strand and the lagging strand?

A. DNA polymerase can work on both the leading and the lagging strand but is much faster on the leading strand.
B. DNA polymerase can use only the leading strand as a template. A different enzyme is used to synthesize DNA on the lagging strand.
C. DNA polymerase can work continuously on the leading strand but works discontinuously on the lagging strand, creating Okazaki fragments.
D. DNA polymerase can work continuously on the leading strand but must flip the lagging strand around before it can work on it.

Refer to the family pedigree shown here. In generation I, one parent is affected by the gene mutation and one parent isn't. In generation II, all three children are affected by the gene mutation. What can you conclude about this gene mutation?

A. All children born in future generations will be affected by this disorder.
B. This gene mutation is a dominant disorder.
C. The generation I mother is a carrier of this gene mutation.
D. This gene mutation is a recessive disorder.