#Question id: 4108
#Unit 3. Fundamental Processes
The yeast Gal4 transcription activator comprises two domains: a DNA binding domain and an activation domain. The DNA-binding domain allows Gal4 to bind to appropriate DNA sequences located near genes that are required for metabolism of the sugar galactose. The activation domain binds to components of the transcriptional machinery (including RNA polymerase), attracting them to the promoter, so the regulated genes can be turned on. In the absence of Gal4, the galactose genes cannot be turned on. When Gal4 is expressed normally, the genes can be maximally activated. When Gal4 is massively overexpressed, however, the galactose genes are turned off. Choose correct explanation for this regulation?
A. In order for Gal4 to work properly, the DNA-bound Gal4 recruits many proteins, including RNA polymerase, to the promoter.
B. When there is too much Gal4 in the cell, the free and DNA-bound Gal4 will compete for the limited quantities of these other components.
C. In the presence of excess Gal4, those components are tied up in unproductive complexes with free Gal4, thereby preventing their recruitment to the promoter.
D. cells that massively overexpress Gal4 grow poorly because of the reduced availability of critical components of the transcription machinery.
E. Over concentration of Gal4 prevent suppressors to bind with DNA
#Question id: 10200
#Unit 6. System Physiology – Plant
Following are some facts regarding C3 and C4 Plants
a.) In C4 plants the reduction is caused by the additional energy requirements such as 1 ATP per CO2 from C3 plants
b.) C4 leaves are exposed to low O2 concentrations, the quantum yields for CO2 fixation remain constant while C3 leaves are exposed to low O2 concentrations quantum yield increases
c.) C3 leaves are exposed to low O2 concentrations, photorespiration is maximized
d.) Plant with the C4 metabolism need more rubisco than C3 plants to achieve a given rate of Photosynthesis
Which of the following combination would be correct?
#Question id: 12052
#Unit 7. System Physiology – Animal
#Question id: 3748
#Unit 3. Fundamental Processes
How are the BRCA proteins and their genes implicated in breast cancer?
#Question id: 29003
#Unit 7. System Physiology – Animal
Parathyroid cell membrane contains___