Welcome to the DNA 2 debriefing.

Answer the questions below. If necessary, click on the Check buttons when you have entered your answer.

1. Which of the following is NOT a difference between DNA and RNA?

DNA uses thymine, RNA uses uracil DNA has two hydrogen atoms at the 2' position, RNA has a hydrogen atom and a hydroxyl group.
DNA has a 5-carbon sugar, RNA has a 6-carbon sugar. DNA is double-stranded, RNA is single-stranded.
Correct! Both DNA and RNA are built around the 5-carbon sugar ribose.
Both DNA and RNA are built around the 5-carbon sugar ribose.
No, that is a difference between DNA and RNA.

2. Predict the mRNA sequence derived from the following DNA sequence (taken from the DNA region that codes for proteins involved in tryptophan synthesis).

CGC CGC TGC GTC AAT

Correct! The mRNA sequence is complementary to the DNA sequence with T replaced by U.

The mRNA sequence is complementary to the DNA sequence with T replaced by U.
Remember, in RNA thymine (T) is replaced by uracil (U).
Remember, A pairs with U and G pairs with C.
One codon in the mRNA strand has been provided for you.

3. What will be the protein sequence specified by the mRNA molecule you entered above?

Click on the blueprint icon to see the genetic code. Use the three-letter abbreviations for the amino acids.

1.

2.

3.

4.

5.

Correct! You have selected the amino acids that match the codons in the mRNA sequence.
At least one of the amino acids you entered is incorrect. The cursor has been placed in its text field.
One of the correct amino acids has been added.
The correct amino acids have been entered. You should review the genetic code to see how the codons in the mRNA sequence specify the amino acids sequence of a protein.

Congratulations!

You have completed the DNA 2 module.

Click on the DNA 2 icon below to return to the Biomolecules gateway page.