BIOCHEM C 785| 2nd OA Readiness Check Exam| Grade A+

The 2nd OA Readiness Check is designed to give you additional practice with new assessment-
stylequestions to help prepare for success on the OA. Thus, please try to mimic exam-like
conditions by taking the test in one <2 hr sitting without any study aids apart from your
whiteboard/scrap paper.
Note: You can take the 2nd OA Readiness Check again if you're so inclined, but you can not
edit your response as you may have done with the topic questions. You will be able to see the
results afterwards.

1. What is the complementary sequence to 3’ ATG CGA ATA 5’?
1/1
3’ TAT TCG CAT 5’

3’ TAC GCT TAT 5’
3’ GAT AGC ATA 5’
5’ ATA AGC GTA 3’
Feedback
The correct answer is 3' TAT TCG CAT 5'. Remember complementary means “Matching or Pairing”You
have to remember to pay attention to your numbers as well as your letters (A-T, G-C, 5'-3'). Thecorrect
answer is
3‟ ATG CGA ATA 5‟ (original sequence)
5‟ TAC GCT TAT 3‟ (complementary sequence)
But we asked for it in the 3‟ direction, so mirror answer to give correct answer:3‟
TAT TCG CAT 5‟


2. Which amino acid sequence would result from this Coding DNA
strand? 3’ ATG CAG ATA 5’?
1/1

,Tyr Val Tyr
Ile Gln Ile
Ile Asp Val

Leu His Lys
Feedback
The correct answer is Ile Asp Val. We are starting at the coding strand, and have to remember the
relationship between coding DNA and mRNA. These two strands are non-complementary and parallel. So
we copy the coding strand , change T ---> U, and then write the mRNA sequence:
3‟ ATG CAG ATA 5‟ coding
3‟ AUG CAG AUA 5‟ mRNA
Mirror by changing orientation: 5‟ AUA GAC GUA 3‟ Read
chart Ile Asp Val (chart is in direction of 5' ---> 3')



3. Which amino acid sequence would be made from this templateDNA
strand? 5’ TAT TAC CGA 3’? *
0/1

,Tyr Tyr Arg

Ile Met Ala
Ser Val Ile
Ser His Gln
Correct answer
Ser Val Ile
Feedback
The correct answer is C because
5‟ TAT TAC CGA 3‟ template is complementary and antiparallel so3‟
AUA AUG GCU 5‟ but it is in the wrong orientation, so mirror
5‟ UCG GUA AUA 3‟ and read the chart
Ser Val Ile



4. Which of the following are the correct components for a PCR
reaction?
1/1
dNTPs, Primer, RNA Polymerase, template RNAdNTPs,
Primer, DNA Polymerase, template DNA

ATP, Primer, mRNA polymerase; template mRNA

, Acetyl CoA, RNA primer, DNA Ligase, Template phosphate
Feedback
The correct answer is b


5. If you had a mother who is homozygous for a recessive disease,and a
father who is a heterozygous carrier, what percentage of children will
have the disease?
1/1
0%
25%
50%

75%
100%
Feedback
The correct answer is c 50%
Homozygous recessive: aa
Heterozygous: Aa


6. Which of the following would represent a silent mutation if this is the
original sequence: 5’ AUC GUA ACA 3’?
1/1