Exam #4 Review

match the nitrogenous bases with their partner

• X

• E

• T

• A

• C

• G

width of DNA too narrow

• Purine + purine

• Pyrimidine + pyrimidine

• Purine + pyrimidine

Which Bases are purines? (select all the apply)

• Thymine

• Guanine

• Cytosine

• Adenine

Which bases are pyrimidines? (select all that apply)

• Thymine

• Adenine

• Guanine

• Cytosine

Out of the three DNA Replications models, which was found to occur in experiments?

• Conservative

• Semi-conservative

• Dispersive

DNA Polymerase​ ​ (a)   the ​ (b)   of new ​ (c)  

• catalyzes
• elongation
• DNA
• RNA
• Proteins
• termination
• transcription
• halts

Match the following

• 1.  adds guanine-rich repetitive seq.

• DNA Polymerase 1

• untwist DNA at the replication forks

• Telomerase

• Replaces RNA with DNA in the lagging str

• DNA ligase

• Join together the seg. of the lagging st

• DNA polymerase 3

• Elongation of new DNA

• Helicase

1. A space probe returns with a culture of a microorganism found on a distant planet. Analysis shows that it is a carbon-based life-form that has DNA. You grow the cells in 15N medium for several generations and then transfer them to 14N medium. Which pattern in the figure above would you expect if the DNA was replicated in a conservative manner?

• A

• B

• C

• D

Cytosine makes up 42% of the nucleotides in a sample of DNA from an organism. Approximately what percentage of the nucleotides in this sample will be thymine?

• 8%

• 12%

• 42%

• 16%

What direction does DNA Polymerase add nucleotides?