third exam key 2010 - Biology 310 Third Midterm Examination...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Biology 310 Third Midterm Examination Spring 2010 Name: [Print]________Key________________ Name:[Signature]____________________ Student number___________________________ Instructions: Write in INK. Examinations written in pencil or erasable ink will not be read and a failing grade will be assigned. DO NOT USE DIAGRAMS FOR ANY ANSWER. The value of each question is shown in parentheses. If your handwriting is poor, PRINT your answers. Illegible answers will not be read and will be given a score of ZERO . Use the back of the pages to write or print your answers if you do not have enough room on the front of the exam. THINK before you write. Make your answers concise and correc t. Ask yourself what the question is really asking. Take your time. We will use the entire 21/2 hours for the exam, even though it has been written as a 60 minute exam. You will note that we are suggesting limits on the amount of writing needed for many answers. This is to prevent excess verbosity. Some students feel if they write everything they can think of for a question we will find some piece of the answer buried in there. We discourage such a practice. _____________________________________________ 1. As cells exit mitosis several events are regulated by the eleven subunit APC complex. a. What is the APC complex and how does it regulate the components of the cell cycle at the end of mitosis. [One-two sentences] [2] The APC complex is a ubiquitin ligase which adds ubiquitin to the cyclins at the end of mitosis for degradation in proteosomes. All this information was required for credit. 2. How is the interaction of cyclins and Cdks regulated? [2] [One-two sentences] They are regulated by phosphatases and kinases. i.e Wee1 kinase and cdc25 phosphatase. 3. A mutation was found in yeast cells in which the cells could not proceed beyond the G 1 phase of the cell cycle. The mutation was traced to a ubiquitin ligase. a. What is a ubiquitin ligase? [One sentence] [1] A ubiquitin ligase adds ubiquitin to proteins thus marking them for destruction in the proteosome. b. Why would a mutation of an ubiquitin ligase block the cell cycle beyond the G 1 phase? [One-two sentences] [2] The cell could not proceed beyond G1 because the cyclin regulating cdk at the end of G1 could not be ubiquinated and thus destroyed.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4. In marmoset cells a mutation causes a failure the kinetochore of chromosome #6 to attach to the spindle. a. What is a kinetochore? [One sentence ] [1] The kinetochors is a protein complex attached to the centromere of chromosomes to which the spindle microtubules are attached. b. What G-protein is involved in chromosome-kinetochore attachment ? [1] ___RanGTP____________- c. One consequence of the mutation was the activation of caspase 9. 1
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 07/22/2010 for the course BIOLOGY 315 taught by Professor Bio during the Spring '10 term at SUNY Stony Brook.

Page1 / 11

third exam key 2010 - Biology 310 Third Midterm Examination...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online