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Appetizer
What's in a Word?
Remembering Last Lesson's Important Points
Main Course
Activity 2.1: Mystery Decoder
Activity 2.2: M&M Codes
*Activity 2.3: Sudoku Codes
Final Course
Dessert
Stuffed, But Still Hungry for More?
SET Concepts Addressed
Leader Supplements for Lesson 2
Handout 2.1: Genome Sequence
Handout 2.2: Decoding Key
Handout 2.3: Sudoku Puzzle
Handout 2.4: DNA Sequencing
Puzzle
Handout 2.5: Genomics Puzzle
Download lesson as PDF
* optional

Appetizer

In Lesson 1 participants learned that diversity results from differences in the all of the genetic recipes or genes in the master cookbook of the organism, which is called the genome. You can think of the genome as many volumes in a master cookbook with each volume containing thousands of recipes.

The genome cookbook is written in combinations of four different chemical units that together comprise deoxyribonucleic acid, or DNA for short. The chemical units are arranged in a code, called the genetic code, which follows a specific set of rules. Some genomes are small; some are larger. Wheat, used to make bread and cookies, contains 32 billion chemical units; the human genome is 20% that size.

The genetic information specified by the code is like the recorded information in the cookbook recipes. The recipes and the DNA both serve to hold information. Just as the alphabet is used to communicate ideas in a recipe through words, the chemicals that make up DNA communicate information about the characteristics of an organism. Substituting one letter for another or inserting/deleting a letter in a word may have no effect on sentence’s meaning or it can dramatically change its meaning. For example, inserting a letter in the following sentence can change its meaning. "I saw my friend eat her sandwich" is different from "I saw my friend heat her sandwich". Substituting a letter in this sentence changes its meaning. "My best friend got an A on his math quiz" certainly differs from "My best friend got an F on his math quiz"! The same situation occurs with DNA. Changing a single chemical unit, referred to as causing a mutation, can have no effects or a profound effect depending on the change.

Next: What's in a Word?

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