The structure and function of DNA

After you’ve read the letter that Francis Crick wrote to his son and found out about the structure and function of DNA, complete these interactive resources to be able to explain the structure and function of DNA inside a nucleus. The resources/ activities are for one school hour and one homework session.

On the side, complete the SoMi self assessment handout.

Animation and quiz: DNA structure

Learn Genetics: What are DNA and genes?

Learn Genetics: What are proteins (remember that making and processing proteins are main cellular processes: the genetic information to make proteins is stored in the DNA code).

Learn Genetics: Build a DNA molecule

Learn Genetics: Things you may not know about DNA

If you have more time, you can also review the interactive section Inside a Cell to review the structure of animal and plant cells.

DNA Microarray Chips

DNA microarray chips are a technology that can be used to analyze gene expression patterns  and monitor the expression of thousands of genes simultaneously. Here are some brilliant resources for independent learning:

DNA Microarray at the DNA Learning Center

DNA Microarray (with an interactive lab exercise) at Learn Genetics, University of Utah

Using a DNA Microarray at Glencoe Biology online (animation and quiz)

Microarrays at Pearson Microbiology (animation and quiz)


p53: Molecule of the Year – Suggestions for independent learning

In 1993 the protein p53 was awarded Molecule of the Year by the magazine Science. It was the time that scientists began to understand that complex cellular regulation mechanisms control the expression of the human genome. The human protein p53 is 393 amino acids long; the abbreviation stands for p for protein and 53 for it’s molecular mass (53 kilodalton). The protein regulates the cell cycle because it is capable of stopping the cell cycle temporarily to allow the repair of DNA damages. If repair mechanisms fail, p53 induces apoptosis (programmed cell death). This mechanism prevents genetic damage to be passed to further generations.

The main focus of the activities this week is put on a) evaluating the quality of website content and b) biological principles of complex human cell cycle regulation processes.


Research on the biological role of p53. In doing so, find and evaluate the quality of several websites first (Tutorials: in English: Evaluate website content, University of Edinburgh || in German: Bewerten von Internetquellen, Universität Hamburg) and choose two sources for your work.

Create a Concept Map to illustrate the biological role of p53 (tutorial here).Only include new content in your concept map and avoid basic knowledge you’ve already learned about p53 in class.

p53: Maintaining Genome Integrity

The Nobel Prize in Chemistry 2015 was awarded „for mechanistic studies of DNA repair“ (click here for further resources, choose popular information). p53 is a protein that acts as a quality control at the cell cycle’s G1 checkpoint; it can be regarded as one component of the ‚cellular toolbox‘ to maintain a cell’s genome integrity.

These resources are helpful supplements to our classroom activities/ studies:

How Tumor Suppressor Genes Block Cell Division

Control of the Cell Cycle

Cell Proliferation Signaling Pathway (Advanced)


Regulation of Gene Expression II (eukaryotes)

In this sequence, you’re going to work in different groups: exam writers and non-writers. Keep in mind that the objective for the end of this week is a) to describe different methods of pro- and eukaryotic protein synthesis control b) compare how prokaryotes and eukaryotes control protein synthesis.

Exam writers:

You obtain an overview of different methods of eukaryotic protein synthesis control based on the animations and their narratives below. On the side, add new information to your existing overview.

Non writers:

You each focus on one method in detail and can outline one method of eukaryotic protein synthesis control in a presentation.

Time available for independent learning: 30 minutes

Overview: Control of Gene Expression in Eukaryotes 

A Closer Look: Regulated Transcription

A Closer Look:mRNA Processing

A Closer Look: mRNA Splicing


Regulation of Gene Expression I (prokaryotes)

In 1961, French scientists François Jacob and Jacques Monod proposed the existence of messenger RNA and a model of gene regulation in E. coli, the operon model. They determined that the levels of lactose in the cell were linked to the regulation of the galactosidase gene (galactosidase is an enzyme involved in lactose breakdown).

After this independent learning session you’ll be able to compare and explain different gene regulation mechanisms found in prokaryotes.

Compete tasks 1,2 and 4 (last page on the handout) based on the print and online materials.

 This activity is scheduled for 90 minutes classroom time (Wednesday and Thursday) and 1 homework activity.

Virtual Cell Animation: The lac-operon

The lac-operon: Combination of switches.

The trp- repressor


The mechanism of DNA replication

The Meselson-Stahl experiment was a milestone in demonstrating the mechanism of DNA replication.

In this lesson you research about the Meselson and Stahl experiments. Based on your research, design a laboratory report from Meselson and Stahl’s point of view on the mechanism of DNA replication.

Animation: Meselson and Stahl experiment 

Interactive resource: Meselson and Stahl experiment

Homework for Monday, 18 January:

PARTNER A: Research about the experiments carried out by Avery and Griffith and outline the experimental design, procedure and result. Explain why the discovery of that experiment contributed to identify that DNA is the material of heredity.

PARTNER B: Research about the experiments carried out by Hershey and Chase and outline the experimental design, procedure and result. Explain why the discovery of that experiment contributed to identify that DNA is the material of heredity.


The epigenome influences DNA and changes the level of gene expression. These resources provide excellent additional information for furhter independent learning and revision:

Epigenetics at LearnGenetics, University of Utah

Cancer Epigenetics: A university lecture delivered by Professor Susan Clark at the Walter and Eliza Hall Institute (24 June 2013), a public science website

ARTE TV Documentation „Wenn Essen auf die Gene schlägt“. You need to find the documentation on the internet.


1 2