1) For each of the following partial diploids, give the cellular phenotypes for A and B. Explain.

Question

A B
a. for a negatively regulated gene:
F’pR- poA-B/ pR po-AB-

F’p-R p-oA-B/ pR- poAB-

b. for a positively regulated gene:
F’pR- poA-B/ pR po-AB-

F’p-R p-oA-B/ pR- poAB-

2) Would attenuation of the type seen in the tryp operon of E. coli be likely to occur in humans? Why or why not?

3) In the yeast gal gene system, in which genes should you be able to isolate mutations which can not turn on the gene?

4) In the developing Drosophila embryo system, what kind of mutation would give rise to:
a. an embryo with 3 abdominal segments missing
b. a fly with the correct number of segments, but had two additional thoracic segments and two fewer abdominal segments.

5) How is it possible for an organism with 20,000 genes to produce millions of different (protein) antibodies?

I was wondering if you could help out with any of these questions to help me study for a test. Thank You