#Question id: 10842
#Unit 10. Ecological Principles
The number of species in a community is referred to as the
#Question id: 26838
#Unit 10. Ecological Principles
#Question id: 2863
#Unit 2. Cellular Organization
The promoter of the araBAD operon from E. coli is activated in the presence of arabinose and the absence of glucose and directs expression of genes encoding enzymes required for arabinose metabolism. Unlike the cases of lac and gal genes, where a repressor and an activator work together, here two activators work together: AraC and CAP
+ arabinose |
AraC binds that sugar and adopts a configuration that allows it to bind DNA as a dimer to the adjacent half-sites, araI1 and araI2 |
– arabinose |
the AraC dimer adopts a different conformation and binds to araO2 and araI1, there is no monomer at site araI2, and so the protein cannot activate the araBAD promoter (araPBAD). This promoter is also controlled by CAP. |
#Question id: 2988
#Unit 2. Cellular Organization
Use the figure to answer the question below.
If the cell whose nuclear material is shown in the figure continues toward completion of mitosis, which of the following events would occur next?
#Question id: 27159
#Unit 7. System Physiology – Animal
This event can cause a damage to the hypothalamus portal system