UNIT 4: DNA Structure & Cellular Reproduction
4A: DNA Structure & Replication
Roadmap for the year:
Unit 1: Interconnectedness of Life
Unit 2: Ecological Biochemistry
Unit 3: Cellular Biology: Structure Leads to Function
Unit 4: DNA Structure and Cellular Reproduction
  • 4A- DNA Structure and Replication
  • 4B- Asexual Reproduction and Mitotic Cell Division
Unit 5: Gene Expression and Inheritance
Unit 6: Evolution and Classification of Living Things
Unit 7: Biotechnology, Human Biology, and Disease / Themes for the year:
How does this unit contribute to your understanding of the following themes?
  • Life on Earth has various Levels of Organization
  • The Structure of Living Things leads to their Function

The Big Picture for Unit 4…
DNA is a self-replicating molecule which is the universal code for life; it enables an organism to transmit hereditary information and, along with the environment, determines an organism’s characteristics.
  • What is the importance of DNA?
  • How is DNA copied and passed from one generation to the next?
  • What is the role of DNA in passing on traits and proper development?

Suggested Resources…
Textbook – Biology (Miller and Levine, 2010) (Sections 12.2, 12.3)
Notes packets
Homework worksheets
Lab activity packets
PowerPoint presentations
Media resources (videos, images, Internet)
Directions: Below are check lists of things you should know and things you should be able to do by the end of the unit. Use this tool to help you prepare for the unit assessment.
By the conclusion of this unit, you should know the following:
  1. Watson, Crick, Franklin and Wilkins are generally credited with the discovery of the double helix structure of DNA.
  2. DNA is a nucleic acid consisting of two long strands of covalently bonded nucleotides, held to each other by hydrogen bonds between complementary nitrogen bases.
  3. A nucleotide contains deoxyribose sugar, a phosphate group, and a nitrogen base (adenine, guanine, cytosine or thymine).
  4. The double-helix model explains Chargaff’s rule of base pairing and how the two strands of DNA are held together.
  5. DNA is a molecule which is able to undergo self-replication using enzymes.
  6. Replication in most prokaryotic cells starts from a single point and proceeds in two directions until the entire chromosome is copied.
  7. In eukaryotic cells, replication may begin at dozens or even hundreds of places on the DNA molecule, proceeding in both directions until each chromosome is completely copied.
  8. A gene is a section of DNA (or part of a chromosome) that codes for a trait or part of a trait.
  9. Changes in DNA (mutations) can occur spontaneously or due to the effect of mutagens. An altered gene may be passed on to every cell that develops from it
/ By the conclusion of this unit, you shouldbe able to do the following:
Name the scientists who contributed to the discovery of the basic structure of DNA.
Identify the chemical components of DNA by labeling/coloring nucleotides and the double helix.

Given a strand of DNA, determine the sequence of the complimentary strand.

Compare and contrast chromatin and chromosomes.

Relate the terms DNA, chromosome, and trait.
Sequence the different parts of the cell cycle and justify the importance of each.

Articulate and/or model the steps of DNA replication.
Given the percentage of one particular nucleotide in a sample, use Chargaff’s rules to determine the relative percentages of the other 3 types of nucleotides.
Recognize when a mutation has occurred during DNA replication, identify its possible causes, and realize that this change might affect the function of the affected gene.

DNA Structue and Replication Terms

Words found in the textbook Page 344:

1) / Adenine:
2) / Guanine:
3) / Cytosine:
4) / Thymine:
Words found in the textbook Page 346:
5) / Rosalind Franklin
6) / James Watson
7) / Francis Crick
Words found in textbook glossary
8) / Chromatin
9) / Chromosome
10) / Base Pairing (complementary base pair)
11) / Eukaryote:
12) / Homologous Chromosome (structures):
13) / Mutation:
14) / Prokaryote:
15) / Replication:
Words NOT Found In Textbook:
1) / Deoxyribose:
2) / Double Helix:
3) / Histone:
4) / Human Genome Project: