Genetic Mutations

Tara McCoy

DeWitt Clinton High School, Bronx

Summer Research Program for Science Teachers

August 2011

Subject:  Living Environment (Biology)

Grade Level: 9 & 10

Unit: Genetics

Lesson:  Cooperative learning (3 students/group)

Learning Objectives:

SWBAT:

Ø  Identify the source of genetic variation in a population.

Ø Explain how genetic variations are not always harmful.

Ø  Describe how mutations can cause genetic disorders

Ø Demonstrate how mutations can cause genetic disorders.

Background Information:

Mutations occur as random chance events. Gene mutations can also be caused by such agents as radiation and chemicals. When they occur in sex cells, the mutations can be passed on to offspring; if they occur in other cells, they can be passed on to other body cells only.

There are two categories of mutations: Gene mutation and Chromosomal mutation.  Chromosomal mutation is most severe since many inherited traits will be affected. Example of Chromosomal mutation would be Down’s Syndrome, extra chromosome. Severe mental and physical impairments in people with Down’s Syndrome.  Genetic mutation could be colored blindness, have difficulty recognizing colors.  Genetic mutations are specific to the gene it is affecting.  Chromosomal mutations are affecting many genetic traits.

Engagement:

1. STUDENTS WILL GET INTO ASSIGNED GROUPS (3-4 STUDENTS)
2. STUDENTS WILL RECEIVE MATERIALS:

• HANDOUTS AND BACKGROUND MATERIALS

                                                         a) Changes to Genetic Code Handout

                                                         b) What is a Mutation Handout

• Post-Its

• DNA Strand (Sentence)

• Instructions Handout

3. GROUPS WILL READ INSTRUCTIONS FOR THEIR RESPECTIVE GROUP.
4. EACH GROUP WILL POST GROUP MUTATIONS ON THE APPROPRIATE POSTER BOARDS.
5. WHEN ALL GROUPS ARE FINISHED, STUDENTS WILL OBSERVE THE POSTER BOARDS AND THE TYPES OF DISEASES/DISORDERS THAT ARE PRODUCED FROM EACH.

 

Exploration: Students will fill out their group charts on the handout.  Students will present to the class how they filled out their chart (handout).  They will discuss each mutation type.  Each group will observe all the findings posted to the poster boards representing the different mutation types.  The group will use their observations to answer the following questions.

Question: “Which mutation type caused the most severe disease/disorders? Explain your answer.” Students will use their observation of the poster boards to support their answers. 

Question: “Which mutation type caused the least severe disease/disorder? Explain your answer.” Students will use their observation of the poster boards to support their answers.

Teacher note: On poster boards, write at top a specific mutation type.  One mutation type for each poster board.  Students will record their data by placing their Post-it notes on the appropriate poster board according to the instruction handout.



Analysis of Results: From group results, observations, and question responses, the students should be able to see the mutation types that are severe (i.e., sentences that don’t make sense) and mutation types that people can live with (i.e., sentences that have English words in them).

 

Assessment: Students will complete homework handout assignment.

 

New York State Standards

Living Environment Core Curriculum

• 2.1a Genes are inherited, but their expression can be modified by interactions with the environment.
• 2.1b Every organism requires a set of coded instructions for specifying its traits. For offspring to resemble their parents, there must be a reliable way to transfer information from one generation to the next. Heredity is the passage of these instructions from one generation to another.
• 2.1c Hereditary information is contained in genes, located in the chromosomes of each cell. An inherited trait of an individual can be determined by one or by many genes, and a single gene can influence more than one trait. A human cell contains many thousands of different genes in its nucleus.
• 2.1f In all organisms, the coded instructions for specifying the characteristics of the organism are carried in DNA, a large molecule formed from subunits arranged in a sequence with bases of four kinds (represented by A, G, C, and T). The chemical and structural properties of DNA are the basis for how the genetic information that underlies heredity is both encoded in genes (as a string of molecular bases) and replicated by means of a template.
• 2.1g Cells store and use coded information. The genetic information stored in DNA is used to direct the synthesis of the thousands of proteins that each cell requires.
• 2.1h Genes are segments of DNA molecules. Any alteration of the DNA sequence is a mutation. Usually, an altered gene will be passed on to every cell that develops from it.
• 2.1i The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins. Protein molecules are long, usually folded chains made from 20 different kinds of amino acids in a specific sequence. This sequence influences the shape of the protein. The shape of the protein, in turn, determines its function.
• 2.1j Offspring resemble their parents because they inherit similar genes that code for the production of proteins that form similar structures and perform similar functions.
• 2.1k The many body cells in an individual can be very different from one another, even though they are all descended from a single cell and thus have essentially identical genetic instructions. This is because different parts of these instructions are used in different types of cells, and are influenced by the cells environment and past history.
• 2.2d Inserting, deleting, or substituting DNA segments can alter genes. An altered gene may be passed on to every cell that develops from it.
• 2.2e Knowledge of genetics is making possible new fields of health care; for example, finding genes which may have mutations that can cause disease will aid in the development of preventive measures to fight disease. Substances, such as hormones and enzymes, from genetically engineered organisms may reduce the cost and side effects of replacing missing body chemicals.
• 5.2g Some allergic reactions are caused by the body's immune responses to usually harmless environmental substances. Sometimes the immune system may attack some of the body's own cells or transplanted organs.