Representing Introns and Exons?
1. Place a 15 cm (a little less than the width of a paper) strip
of masking tape on your desk. The tape represents a gene.
2. Use two colors to write the words appropriately joined on
the tape exactly as shown in the diagram below. Space the
letters so they take up the entire length of the strip of tape.
The segments in one color represent introns; those in the
other color represent exons.
Appropriately joined
3. Lift the tape. Working from left to right, cut apart the
groups of letter written in the same color. Stick the pieces
of tape to your desk as you cut them, making two strips
according to color and joining the pieces in their original
order, on your desk.
4. Put the two strips onto your piece of paper
5. Determine from the resulting strips which strip is made on
“introns” and which is made of “exons.” Label each of
your paper.
6. Answer the following: (use pg223 of you textbook for
help)
A:
1. What is the difference between pre-mRNA and the final mRNA that leaves the
nucleus?
2. Explain the purpose of “pre-RNA splicing”?
3. What is a splisosome?
4. Predict what might happen to a protein if an intron were not removed.
5. Compare and contrast prokaryotic and eukaryotic genes and translation
B: Read “Junk DNA article and answer “discussion questions.”