1. An Introduction to the Genetic Code of Life! By C. Rhein
WHY IS YOUR
SKIN GREEN?
An Introduction to the Genetic Code of Life!
By C. Rhein
To Activity
Teacher’s Page

2. Teacher’s Page Map objectives:
The learner will be able to understand that DNA is comprised of four subunits: A,G,T,C.
The learner will be able to understand that genetic material is found in molecules of DNA.
The teacher should view this program before the presentation in class. This should be used as an introduction to genetics or heredity.
The students need a science journal to write down answers to the questions and facts about the structure and function of DNA.
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3. In the science journal, write the question and answer.
What encodes all
of your genetic
instructions?
For example, what determines your
eye color, your skin color,
or your hair color?
Move forward
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4. DNA (deoxyribonucleic acid) Your DNA contains your genetic code
DNA (deoxyribonucleic acid) Your DNA contains your genetic code! Facts to write in your science journal!
DNA is a nucleic acid.
Nucleic acids are made up of smaller units called nucleotides.
Three components of a DNA nucleotide:
1. Deoxyribose (a simple sugar)
2. A phosphate group
3. A nitrogenous base
Parts of a nitrogenous base
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5. Let’s make a Concept Map!
DNA NITROGEN BASE
In DNA there are four possible nitrogenous bases:
adenine (A)
guanine (G)
cytosine (C)
thymine (T)
Let’s make a concept map in the science journal with the components of DNA.
Let’s make a Concept Map!
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6. CONCEPT MAP Write the Concept Map and missing word in the blank!
DNA nucleotide
component
component
component
Contains either
DNA nucleotides do not exist as individual molecules. Nucleotides combine to form two long chains, producing one large molecule.
Click to see a picture of DNA
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7. Learn more about the structure
The four nitrogenous bases are paired along the sugar-phosphate backbone in a particular order. This is called the DNA Sequence:
Adenine (A) pairs with Thymine (T)
Cytosine (C) pairs with Guanine (G)
A-T and C-T are referred to as base pairs.
The two DNA strands are held together loosely by weak hydrogen bonds between the bases.
The sugar of one nucleotide is joined to the phosphate group of the next nucleotide by a covalent bond.
LOOK CLOSELY AT THE DNA STRUCTURE AND DRAW IT IN YOUR JOURNAL!
DO NOT FORGET TO LABEL!
Learn more about the structure
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8. Adenine and Guanine are double-ring bases called purines.
Thymine and Cytosine are smaller, single-ring bases called pyrimidines.
This pairing produces a long two stranded molecule compared to a ladder. But the ladder is also twisted into a structure called a:
DNA REVIEW
Double Helix
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9. In your journal, write the missing base on the strand of DNA!C T A
One last question about DNA
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10. Please, write this question in your science journal with the answer.
The genetic material of all living things is made up of DNA containing nucleotides with adenine, thymine, guanine, and cytosine.
Please, write this question in your science journal with the answer.
How can organisms be different from each other if their genetic material is made of the same nucleotides?
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Answer

11. They are different because the order of nucleotides in the DNA strands of the two organisms is different.
The more closely related two organisms are, the more alike the order of nucleotides in their DNA will be.
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THE END!