1. What is the name of the section of DNA that unwinds in order to be transcribed during protein synthesis?
ANS: a gene
2. What is the function of a gene?
ANS: To produce the recipe for a protein
3. What is the name of the process that assembles proteins on the ribosome?
ANS: translation
4. When does replication occur?
ANS: During “S” phase of interphase

5. Translation is accomplished by what molecule?
ANS: tRNA
6. Name of the process that uses DNA to make mRNA
ANS: transcription
7. Molecule carrying a codon
ANS: mRNA
8. Codons for “stop”
ANS: UAA; UAG; UGA
9. AUG=
ANS: start

10. Many prokaryotes do not produce intervening segments of less understood code in the mRNA that is transcribed
(introns). It is possible to determine the original sequence of
DNA from the sequence of amino acids carried in by the tRNA. Given the sequence below, and using the codon chart, determine one possible DNA sequence:
Alanine-Isolucine-Tryptophan
ANS:
CGA-TAA-ACT
CGG-TAG-ACT
CGT-TAT-ACT
CGC-TAA-ACT
You must first “un-translate” by turning amino acid sequence into a codon, and then turn the codon into the DNA message.

11. Where do Okazaki fragments form?
ANS: on the lagging strand (5’-3’) of DNA
12. During what process do Okazaki fragments form?
ANS: DNA replication
13. The name given to the daughter DNA complement that forms in continuous fashion is…
ANS: leading strand
14. In what direction is the parent strand of DNA always read?
ANS: 3’-5’
15. DNA segments that can move around on a chromosome…
ANS: transposon

16. What is the name given to the small circular extrachromosomal DNA in noneukaryotes?
ANS: plasmids
A B
17. What is one function of a plasmid?
ANS: convey antibiotic resistance to the organism
18. Which of the above molecules is deoxyribose?
ANS: A
19. How do you know?
ANS: because of the hydrogen on the 2’ carbon, instead of a hydroxide group.

20. What are the less understood segments in the genetic code that must be excised before a mature mRNA molecule can be produced called?
ANS: Introns
21.On what molecule would you find the anticodon?
ANS: tRNA
22. Why do frameshift mutations have the potential to be the most “life-altering” of all the mutations?
ANS: if the mutation occurs near the beginning of the genetic code, then the entire message could be disrupted, creating a completely different protein.

23. Using the codon chart to the right, what sequence of amino acids will the following anticodons carry in?
UAC; AAA; UGU
ANS: Methionine;
Phenylalanine; Threonine
24. What is the function of a snRNP?
ANS: A “snurp” basically functions to cut introns out of
(excise) the free transcript’s message, and then reattach the exons back together.

25.What sequence of events MUST occur in order for a free transcript to become a mature mRNA?
ANS: First, the introns must be excised, and the exons be joined together. Then it must acquire a poly-A tail, and a cap.
26.During what processes does “termination” occur?
ANS: Replication; Transcription; Translation
27. Briefly describe termination during replication.
ANS: A repeating sequence of “TAG” occurs on the DNA template, called a telomere, signaling an end to the process, slightly shortening the DNA copy each time.

28. The bond that forms between the nitrogenous bases…
ANS: hydrogen
29. The bond that forms the “backbone” of the DNA molecule, between the phosphate and two sugars…
ANS: phosphodiester
30. What is the significance of each of these bonds and their formation?
ANS: Hydrogen is weak, between the bases, so they can separate easily with just a nudge from an enzyme.
Phosphodiester is strong covalent, making it far less likely to break (which may produce mutations that are not conducive to life)

31. Describe the “wobble” effect, in terms of protein synthesis.
ANS: There is a “loosening” of the base-pairing rule during translation. When codons are interpreted by anticodons, they aren’t strictly read. The third base in the group may not matter at all in the interpretation of the message, and the actual amino acid that is carried in.
32. Why would it be impossible to determine the original
DNA sequence that coded for the following amino acid sequence?
Methionine; Alanine; Valine; Glutamine; Stop
ANS: Because the original DNA message could have included many introns that were unnecessary, and were, therefore, excised out.