Download DNA Study Guide Answer Key

DNA Study Guide
ACT Course Standards:
C-1.a: Describe the basic structure and function of DNA, mRNA, tRNA, replication, transcription, and translation
C-1.c: use mRNA codon charts to determine amino acid sequences of example polypeptides
C-1.d: use mRNA codon charts to determine the effects of different types of mutations on amino acid sequence and
protein structure.
1. What does DNA stand for? Deoxyribonucleic acid
2. Where it is located? In the nucleus of your cell
3. What is DNA? It is your genetic code
4. What are the subunits of DNA? Nucleotides
5. What are the 3 parts of a DNA nucleotide? Nitrogen base, deoxyribose sugar, and a phosphate group
6. What are the 4 nitrogen bases found in DNA? Adenine, Guanine, Cytosine, and Thymine
7. Illustrate and label a DNA nucleotide. (on back of this paper)
8. Which nitrogen bases pair together in DNA? A-T and G-C
9. What is the shape of DNA? A double helix
10. How many strands of nucleotides are in DNA? 2
11. Why is DNA replication necessary and important? In order to pass exact copies to daughter cells
12. Define the following:
a. Helicase: An enzyme that moves along the DNA molecules breaking hydrogen bonds
b. DNA polymerase Attaches at many different spots on the DNA chains, adds complimentary nucleotides in effort
to copy DNA
13. What are the possible implications of mutations during replication? Not being able to make correct protein
14. Other than mistakes in replications, list 2 examples of what else may cause mutations in DNA.
Smoking and UV rays
15. What does RNA stand for? Ribonucleic acid
16. What are the 4 bases found in RNA? Adenine, Uracil, Guanine and Cytosine
17. Illustrate and label a nucleotide found in RNA. (on back of page)
18. Where does transcription (copying RNA from a strand of DNA) occur? In the nucleus
19. What is a codon? Segments of RNA that contain 3 nucleotides
20. RNA codes for amino acids which are the building blocks of protein
21. What are the subunits of RNA? nucleotides
22. Define the following:
a. RNA polymerase A protein that adds nucleotides to RNA
b. Transcription DNA to RNA
c. Translation RNA to amino acids (proteins)
d. mRNA; messenger RNA- carries “message” from DNA in nucleus to cytoplasm to be decoded for proteins.
e. tRNA; transport RNA- carries amino acids to mRNA for protein synthesis
23. Compare DNA and RNA in the following chart:
DNA
RNA
Deoxyribose sugar
Ribose sugar
2 nucleotide chains
1 chain
Nitrogen base Thymine (T)
Nitrogen base uracil (U)
24. Complete the complimentary DNA strand for the following base pairs.
A-T-T-G-C-A-C-C-G-A-T-A
T-A-A-C-G-T-G-G-C-T-A-T
26. Transcribe the following DNA strand.
A-C-G-G-A-A-T-C-G-T-T-C
U-G-C-C-U-U-A-G-C-A-A-G
27. Using the RNA strand from #26 and the chart in your book, list the amino acids that the RNA codes for.
Cys – leu – ser – lys
28. Describe the following types of mutations.
A. substitution- one nitrogen base is replaced with another
B. deletion- one or more nitrogen bases are removed from the DNA strand
C. insertion- one or more nitrogen bases are inserted into the DNA strand
D. frameshift- caused by insertion or deletion; the gene is altered so that the message no longer codes for the correct
protein (because the codon is shifted)