Background

Genetics, the branch of biology that studies biological inheritance, or how traits are passed down from one generation to the next, is a fascinating and hugely important topic. Fundamental concepts of genetics were first established by Gregor Mendel, an Austrian-Hungarian monk and scientist who is now considered to be the father of modern genetics. Mendel developed his theories of heredity through careful experiments with pea plants in his monastery garden.

There are two fundamental concepts in genetics that were first theorised by Mendel: genes and Mendelian inheritance. Genes are the basic units of heredity, located on chromosomes, which carry the information that dictates how organisms develop and function. Mendelian inheritance, on the other hand, refers to how these genes are passed down from parents to offspring, leading to the segregation of traits.

In the 20th century, the understanding of these concepts was greatly enhanced by the advancement of molecular biology, which enabled the discovery of DNA and its structure, the transcription and translation of DNA into proteins, and the replication of DNA. These advancements have allowed for a detailed and comprehensive picture to be built up of how genes work and are inherited, leading to huge advances in medicine, agriculture, ecology and many other fields.

Genetics has profound implications for our world. Applications of genetics can be found in fields as diverse as medicine, with genetic medicine enabling the diagnosis and treatment of genetic diseases, agriculture, where genetic engineering leads to more productive or disease-resistant varieties of plants and animals, and law enforcement, where forensic DNA is used to solve crimes.

However, genetics also brings with it complex ethical and privacy issues. For example, could genetic information be used to discriminate against or stigmatise individuals or ethnic groups? Who should have access to our genetic information and how should it be protected? How should gene-editing technology such as CRISPR-Cas9 be regulated to ensure it is used in an ethical and equitable way? These are all important issues that genetics raises, and ones that we all need to consider.

To learn more about this topic, and to provide a good foundation for your project, we recommend the following resources:

• The Complete Guide to Human Genetics: A special report from the Genetic Science Learning Center at the University of Utah that gives a comprehensive overview of genetics.

• BBC Bitesize - Genetics: An educational resource from the BBC website with videos, text and quizzes on the subject.

• Videos from Khan Academy on the topic, including Heredity: Crash Course Biology #9, which gives a clear and concise overview of the basics of heredity.

Activity

Activity Title: "Heredity and Family Trees"

Project Aim

The aim of this project is to familiarise students with basic concepts in genetics and Mendelian inheritance. By constructing a family tree, students will explore how traits are passed from one generation to the the next, and how these traits may vary or stay consistent.

Detailed Project Description

Groups of students should choose a specific physical characteristic (e.g. blue eyes, curly hair, height, a genetic disorder). They should then research and gather information about the inheritance of this characteristic, such as how it is determined genetically and how likely it is for an individual to inherit this characteristic from their parents.

Students will then construct a three generation family tree (grandparents, parents and children), showing the inheritance of the chosen characteristic over each generation. For each individual in the family tree, students should indicate whether or not the individual has the characteristic and should mark the possible gene combinations that could result in the presence or absence of the characteristic.

Students should then use the family tree to predict how the characteristic is likely to be inherited in future generations, and to discuss what factors could influence its inheritance.

Required Materials

1. Paper, pens, pencils, highlighters etc. to draw the family tree.
2. Access to the internet for research.

Detailed Step-by-Step Guide to the Activity

1. Divide students into groups of 3-5.
2. Have each group choose a specific physical characteristic or genetic disorder for their project.
3. Have students research the inheritance of the chosen characteristic/genetics - how it is inherited, how likely it is to be passed on, what genes are involved etc.
4. Using the information gathered, have students create a three-generation family tree, showing the inheritance of their chosen characteristic.
5. For each individual in the tree, indicate whether or not they have the characteristic, and the possible gene combinations that could result in its presence or absence.
6. Have students use their family tree to predict the likely inheritance of the characteristic in future generations, and discuss possible influences.

Project Submission

The project submission should include the following:

1. The completed family tree, fully annotated and interpreted.
2. A written report, which should include the following sections:
   • Introduction: Students should introduce the characteristic they have chosen, why they have chosen it, and the importance of genetics in studying the characteristic.
   • Method: Students should outline the theory behind the genetics of their chosen characteristic, and explain how they constructed their family tree. This section should also discuss the likely inheritance of the characteristic in future generations, based on the family tree.
   • Conclusion: Students should conclude by summarising the importance of genetics in the inheritance of this characteristic, what they have learnt from their project, and what conclusions they have drawn based on the family tree.
   • Bibliography: Students should list all of the sources they used to complete the project, including books, websites, videos etc.