Name: _______________________________________________ Date: __________________ Period: __________
DNA History, Structure and Replication Quiz Study Guide - Key
Covered Topics
* DNA
* Replication
* Materials to Reference
* DNA History and Structure Notes
* DNA Replication Notes
* 12-1 Reading Support
* Structure of DNA Homework
Concepts to Understand
* DNA History and Structure Notes
1. What is a nucleotide? A monomer of our nucleic acids
What are the three parts of a nucleotide?
1. Sugar (Deoxyribose)
2. Nitrogenous Base
3. Phosphate Group
2. Describe the difference between purines and pyrimidines. Pyrimidine: cytosine or thymine (base with 1 ring), purine: adenine or guanine (base with 2 rings)
3. What bases are purines? Adenine and guanine
4. What bases are pyrimidines? Cytosine and thymine
5. Describe Chargaff’s contributions to the study of DNA. Analyzed nitrogen base composition in a piece of DNA and discovered that: number of guanine = cytosine, number of adenine = thymine
6. What are the base pairing rules? A-T and C-G
7. Provide the complementary base pairs for this sequence:
ATTACCGAGTCGATATGC
TAATGGCTCAGCTATACG
8. Draw and label a diagram of DNA including:
1. Sugar phosphate backbone
2. 4 complementary base pairs
3. Hydrogen bonds
9. Why is DNA considered antiparallel? On one side the nucleotides face up and the other side they face down
* DNA Replication
10. Describe the direction in which DNA is read correctly. What does this mean? DNA is read from the old strand in order to replicate it on the new strand antiparallel to it
11. Describe where prokaryotic DNA is found and what it looks like. Circular DNA in the cytoplasm
12. Describe where eukaryotic DNA is found and what it looks like. Double helix coiled around histones coiled into a chromosome within a nucleus
13. Define histone. Protein that chromatin is wrapped around
14. Define nucleosome. Chromatin wrapped around a histone
15. Define chromatin. DNA sequence attached to sugar, phosphate backbone
16. What is DNA Replication? Process of creating a copy of DNA prior to cell division
17. What is the replication fork? Where the DNA separates
18. What is the replication bubble? Location where DNA is actively taking place
19. Explain the semi-conservative model of DNA replication. 1 old (template) strand & 1 new strand
20. Explain the steps of DNA replication:
Step 1: DNA separates at the fork (unzips)
Step 2: 2 DNA polymerases attach in pointed in both directions
The enzyme that joins individual nucleotides, proofreads for mistakes
Step 3: Each old strand acts as a template since the bases are complementary to each other
Step 4: When completed, DNA polymerase pops off, new strand is ready for a new cell
21. Why does a cell have to replicate its DNA? Has to duplicate before a cell divides