Name 

_______________________________________________ Date: _________________ Period: ______

Biology: DNA Review Packet

Read each question and fill in the proper answer.
1. Label EVERY sugar (S), phosphate (P), and nitrogen base (A, T, C, G) in the diagram below.

P P P P P

S S S S S

C T A

#2 T G

S S S S S

P P P P P

Nucleotide
2. Examine the objects inside the box labeled #2. What is this called? ___________________________

3. What is the special shape of DNA called? _______________________________________________
Double Helix

4. Which type of chemical bonds will join the two DNA bases? ________________________________
hydrogen bond

5. Which nucleotide part(s) make up the outside of the DNA ladder?            Sugar     Phosphate     Base

6. Which nucleotide part(s) make up the rungs of the DNA ladder?            Sugar     Phosphate     Base

DNA Replication (Review your notes on “replication” to help you answer these questions.)
7. Put the pictures of DNA replication in order by placing a 1, 2, or 3 on the line above the picture.

8. Describe what is happening on the lines below the picture. Be sure to include the names of any 
enzyme involved.

_______________
3 _______________      
1 _______________
2

____________________
DNA polymerase _____________________      
DNA Helicase splits the _____________________
free floating DNA nucleotides
reconnects 2 DNA DNA molecules match to the open DNA
____________________
strands _____________________       _____________________
 ____________________ _____________________       _____________________
DNA and RNA Comparison
9. Complete the following chart by comparing DNA, mRNA, and tRNA. Sample answers have been 
provided.

DNA mRNA tRNA

messenger ribonucleic Transfer ribonucleic
acid acid
Molecule  Deoxyribonucleic acid
full name

Name of  deoxyribose ribose

sugar Ribose

Nitrogen  Adenine, Uracil,

Bases 
Adenine, thymine, cytosine, Adenine, Uracil, 
guanine Guanine, Cytosine
Present Guanine, Cytosine
transfers an amino acid
copies the dna and to a ribosome
carries the code to a
ribosome
Stores genetic 
Function information

10. For each statement write DNA, mRNA, or tRNA.

DNA Holds the original coded information for  DNA Found in the nucleus only

making proteins
tRNA Found in the cytoplasm only
DNA Can replicate itself
mRNA Found in both the nucleus and cytoplasm
mRNA Copies DNA’s coded message
mRNA Carries the coded message to the ribosome
tRNA Carries amino acids to the ribosome for  tRNA
assembly Contains anticodons

11. For each statement write either DNA helicase, DNA polymerase, RNA Polymerase

DNA polymerase Reconnects DNA during replication

RNA polymerase Separates DNA during transcription

DNA helicase Separates DNA during replication

 12. Follow the rules of transcription and fill in the boxes below?

G A C U U A

13. Below is a strand of mRNA. Follow the rules of translation and fill in the tRNA codes below?

G A C A U G

14. What are the tRNA nucleotides called? __________________________________
Anticodon

15. Which two amino acids does the following DNA strand code for?

GLYCINE ASURAGINE
16. From the DNA information given, fill in the missing information.
DNA mRNA tRNA Amino Acid
T T T AAA UUU LYSINE
17. From the tRNA information given, fill in the missing information.
DNA mRNA tRNA Amino Acid
GTT CAA G U U GLUTAMINE
18. From the amino acid given, fill in the missing information.
DNA mRNA tRNA Amino Acid
TAC AUG UAC METHIONINE
Transcription and Translation: Use the picture to answer the questions 19­22.
 19. Describe what is forming and happening in AREA A of the diagram. 
____________________________________________________________________________________
Transcription is taking place inside area A. mRNA is combining with the strand of DNA
____________________________________________________________________________________
____________________________________________________________________________________
20. Describe what is being gathered and happening in AREA B of the diagram. 
____________________________________________________________________________________
tRNA are gathering the correct amino acids. Soon they will be delivered to the ribosome in
area C.
____________________________________________________________________________________
____________________________________________________________________________________
21. Describe what is being assembled and happening in AREA C of the diagram. Tell about each site.
____________________________________________________________________________________
In area C, the ribosome is performing the process called translation. One by one, anamino acid is
being delivered to the ribosome by the transfer RNA.
____________________________________________________________________________________
____________________________________________________________________________________
22. Examine area C. List the amino acids that will be delivered to this ribosome from start to finish. (you 
will need to use the mRNA code and a codon chart which can be found on the next page.)
1st = __________________________ 2nd = __________________________
3rd = __________________________ 4th = __________________________
5th = __________________________ 6th = __________________________
­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­
23. Which mRNA codon will start the process of translation? __________________________________
AUG

24. Which amino acid does every protein begin with? ________________________________________
METHIONIDE
 25. Which mRNA codons will end the process of translation? __________________________________
Stop codons UAA, UAG, UGA

Honors only
26. Why must the pre­mRNA be modified before it can leave the nucleus.
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
27. What are the purposes of introns and exons? Which one needs to be removed and what removes them?
__________________________________________________________________________________
__________________________________________________________________________________
_______________________________________________________________________________

28. Explain the promoter region or mRNA. 
__________________________________________________________________________________
__________________________________________________________________________________
_______________________________________________________________________________
29. Explain initiation, elongation, and termination. 
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
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