DNA and Chromosome Structure

Authors

• Don Lee, University of Nebraska-LincolnFollow
• Walter P. Suza, Iowa State UniversityFollow

Document Type

Learning Object

Date of this Version

2021

Citation

Plant and Soil Sciences eLibrary (PASSeL) Lessons.

Comments

Published 2021, the authors. Used by permission.

This lesson creation was supported in part by Iowa State University Libraries Open Educational Resources initiative.

Abstract

Overview

This lesson describes the chemical structure of DNA and how the structure relates to genes and chromosomes. The replication of DNA prior to cell division to create the chromatids of replicated chromosome is illustrated, showing how the main DNA replicating enzymes work together in living cells.

Learning Objectives

At completion of this lesson you should be able to:

1. Detail the molecular nature of a gene.
2. Recognize when and where replication of the DNA that is packaged in an organism’s chromosome is happening for growth, maintenance, and reproduction.
3. Describe how chromosome replication speed can be increased with multiple origins of replication and bidirectional replication.
4. Explain the role of each of the primary DNA replicating enzymes in conducting replication of a chromosome. Include the role of these enzymes in ensuring the accuracy of the replication process.
5. Predict how the semiconservative replication of a double stranded DNA will proceed given the structure of the molecule and the specific function of the DNA replicating enzymes.

Modules

1. Overview
2. Learning Objectives
3. Introduction
4. Chemical Structure of DNA Subunits
5. Packaging of DNA Into Chromatin and Chromosomes
6. DNA Replication
7. When and Where
8. Speed of Chromosome Replication
9. The Chromosome Replicating Team
10. Step 1: Initiating replication at the Ori
11. Step 2: Priming DNA with RNA
12. Step 3: Synthesis of leading and lagging strands
13. Step 4: Ligation of Okazaki fragments
14. Summary
15. Activities