In Class
Work Hard. Get Smart.
1. Pen/Pencil/
Geneticist’s Name: _________________________________ Class: 8__ Date: ______________
And Binder
_______
Mrs. Bouchard – 8th Grade Science
2. 100% Effort _______
DNA
3. On time
_______
4. Speak/Think/ as a
Scientist
_______
Total:
DNA (deoxyribose nucleic acid) molecules are large and complex. They carry the _____________
______________________________________________________________________________.
Except for identical twins, each person’s DNA is _________________.
DNA can be cut up and separated, forming a sort of “bar code” that is _____________________
______________________________________________________________________________.
DNA is composed of 4 bases: _______________.
Directions: Read the following text on this page and the next page. Then, answer the
questions.
A strand of DNA (Deoxyribose nucleic acid) looks like a twisted ladder. This shape is known as a
double helix. The two sides of the ladder are made of alternating sugar parts and phosphate
parts. The rungs of the ladder are made with a pair of bases. A (adenine) on one side of the
ladder always pairs with T (Thymine) on the other side. G (Guanine) always pairs with C
(Cytosine). These matching pairs are considered to be complementary. The width of the
DNA ladder matches the combined width of the matching bases. Only the correct pairs of
bases fit within the ladder’s width. This also allows for the DNA structure to be split down
the middle, or unzipped, when it is time to make copies of the DNA strand.
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Work Hard. Get Smart.
Directions: Please answer the questions using complete sentences.
1. What are the four bases that make up DNA?
2. What is the basic structure of DNA?
3. Where is DNA stored?
4. What is the difference between genes and chromosomes?
5. If DNA has the same basic characteristics for all living things, why are all living things so
different? How is that possible?