Name: ______Date:______Period: ______

Chapter 12 Review Guide

Part I. Please complete the following questions from your book: pg. 315 (1-10; 14-17; 19-23).

Part II. Complete the following review handout.

12-1: Fill in the following chart for the important scientists

Scientist

/

Briefly describe experiment

/

Important Contribution

Griffith

Avery
Hershey-Chase
Watson and Crick
Rosalind Franklin

1. DNA is made up of monomers called ______, and each monomer is made up of 3 parts (list them):

2. a) Describe the structure of DNA

b) What are the base pairing rules?

3. Differentiate between chromatin and chromosomes.

4. Differentiate between histones and nucleosomes.

5. When are chromosomes visible in the cell?

DNA Replication

6. What do the DNA "instructions" (genes) code for?______

7. What is the purpose of DNA replication?

8. When and where does DNA replication occur?

9. Explain the role of the enzyme Helicase in DNA replication?

10. Explain the role of DNA polymerase (it has 2 functions remember)?

11. What are the nitrogenous bases found in DNA?

12 Assume the original DNA strand has been “unzipped” and DNA polymerase is adding each complimentary nucleotide. Fill in the complimentary DNA sequence for each strand.

Strand 1Strand 2

C-G-

T A-

A- T-

T- A-

A- T-

G- C-

C- G-

T- A-

C- G-

13. DNA replication results in two DNA molecules (circle your answer)

A.each with two original strands

B.each with one new strand and one original strand

C.one with two new strands and the other with two original strands

D.each with two new strands

Transcription

14.What is the purpose of mRNA?

15.How is RNA different than DNA?

a)

b)

c)

16.What is transcription?

17.Why is it necessary to make an mRNA strand?

18.Transcribe the following DNA strand?

DNA: A T T- C T C- G A G- T C A- TGA

mRNA :______

Translation

19. What RNA molecules are involved in translation (3 of them)? Give their function.

20. What is the difference between a codon and an anticodon?

21. If the code on a DNA is AAT, what is the mRNA codon? ______What would be the tRNA anticodon (remember it’s a compliment to the mRNA strand)? ______What amino acid would be brought? ______

22. Where does transcription happen? ______translation? ______

DNA replication? ______

23. a) How many mRNA bases are in 5 codons? ______

b) If there are 21 mRNA bases, how many codons are there? ______

24. If a piece of DNA contains 85 base-pairs (170 total bases), how many guanines are represented if

there are 12 thymines? (show your work)

25. What is the difference between a gene mutation and a chromosome mutation?

  1. Define point mutation.
  1. Define frameshift mutation.
  1. Explain what is meant when a mutation can cause a change in the “reading frame” of a genetic message (making a protein). (read pg. 307 again in your book).
  1. original DNA: TAC-GCA-TGG-AAT

mRNA:______

protein:______

mutated DNA: TAC-GTA-TGG-AAT (what kind of mutation?______)

mRNA: ______

protein: ______

  1. Did the mutation on the original strand of DNA in question #29 cause any changes to the protein produced? (explain in detail).
  1. original DNA: TAC-GCA-TGG-AAT

mRNA:______

protein:______

mutated DNA: TAT-CGC-ATG-GAA-T (what kind of mutation?______)

mRNA: ______

protein: ______

  1. Did the mutation on the original strand of DNA in question #31 cause any changes to the protein produced? (explain in detail).
  1. Decode the secret message hidden in the DNA strand below.

DNA: ACC-TAA-TAC-AGA-ATC-AGA-TTA-AAT-GCA-TAC-TAA-ATC-GTA-CGA-AGA-ATC- CTT-

TAA-TTT-AAT-AGA-ATC

mRNA: ______

______

Secret Message: (write down the first letter of each amino acid/ stop indicates a space between words).______