Download doc Practice Midterm 2006

PRACTICE MIDTERM EXAM BIOL 200 2006
IMPORTANT NOTE: This exam is substantially longer that the actual midterm
exam will be.
FILL IN THE BLANK
1. In the lac operon, the lac repressor binds to the ____________________.
2. If the adenine content of DNA from an organism is 36%, the guanine content is
_________________.
3. A protein composed of two polypeptide chains that are different from each other is
called a __________________.
SHORT-ANSWER QUESTIONS
These questions are intended to test your understanding of concepts that have been
covered in the course. These questions can usually be answered in 25 words or less,
certainly no more than 50. While a precise word count of your answers will not be
conducted, excessively long answers and inclusion of irrelevant information may be
penalized on the actual exam.
1. Identify three types of post-transcriptional regulation of protein-coding genes.
2. Describe three features of eukaryotic mRNAs that generally are not shared with
prokaryotic mRNAs.
3. Which of the common Watson-Crick base pair in DNA is the most stable? Why?
How does this property affect the melting temperature of DNA?
4. The three-dimensional structure of a protein is determined by its primary, secondary,
and tertiary structures. Define the primary, secondary, and tertiary structures.
5. What do TATA boxes, initiators, and CpG islands have in common?
QUESTIONS CONCERNING GENERAL CONCEPTS AND/OR
INTERPRETATION OF EXPERIMENTAL RESULTS
These questions are intended to determine how well you know, and can apply, the
concepts covered in class. As for the questions above, it is important that your answers
are concise and unambiguous, and that they directly address the questions posed.
1. Which of the common Watson-Crick base pairs is more stable? Why? How does this
property affect the melting temperature of DNA?
2. You obtain the sequence of a gene containing 10 exons, 9 introns, and a 3’
untranslated region containing a polyadenylation consensus sequence. The fifth intron
also contains a polyadenylation site. To test whether both polyadenylation sites are used,
you isolate mRNA and find a longer mRNA from muscle tissue and a shorter mRNA
from all other tissues. What is the likely mechanism involved in the production of these
two transcripts?
3. What is the functional advantage of heterodimeric transcription factors?