731. Sickle cell disease is due to
A. a mutation in the beta chain of Hb
B. a mutation in the alpha chain of Hb
C. infection with a parasite
D. none of the above

732. The four subunits of the hemoglobin (Hb) gene represent protein’s
A. primary structure
B. secondary structure
C. tertiary structure
D. quaternary structure

733. Sex lethal (sxl) in Drosophila is transcribed when
A. the X autosome balance is less than 0.5
B. the X autosome balance is 1 or greater
C. the X autosome balance equals 0.5
D. none of the above

734. A mutation in the tip binding site of the repressor would result in
A. constitutive trp operon expression
B. inducible trp operon expression
C. no operon expression
D. none of the above

735. The first protein complex to bind to the TATA box is
A. transcription factor IIA
B. transcription factor IIB
C. transcription factor IID
D. all of these

736. Which of the following is not part of the lac operon?
A. I
B. O
C. P
D. none of these

737. The lac operon is transcribed in which segments?
A. 1
B. 2
C. 3
D. 4

738. A frameshift mutation occurs in the sigma subunit gene transcribed as part of SPOl early genes. What will be the immediate result?
A. Early genes will not be translated
B. Middle genes will not be transcribed
C. The bacterial host will lyse immediately
D. Infection will proceed as usual

739. In the presence of high levels of tryptophan
A. attenuator allows transcription of trp structural genes
B. attenuator propogates transcription
C. attenuator terminates transcription
D. none of the above

740. Tubulin is regulated by
A. binding of tubulin to tubulin mRNA
B. splicing of the tubulin transcript
C. binding of tubulin to the tubulin translational product
D. binding of tubulin to DNA