#Question id: 2222
#Unit 2. Cellular Organization
The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl), and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.
In the U-tube experiment illustrated above, which of the following statements correctly describes side B at equilibrium?
#Question id: 18383
#Unit 12. Applied Biology
#Question id: 11484
#Unit 7. System Physiology – Animal
Two students studying physiology taste a known "bitter" substance, and both report sensing bitterness. They then sample another substance. Student A reports sensing both a bitter taste and a salty taste, but student B reports only a salty taste. What is the most logical explanation?
#Question id: 4539
#Unit 3. Fundamental Processes
The yeast S. cerevisiae exists in three forms: two haploid cells of different mating types—a and alpha and the diploid formed when an a and an a cell mate and fuse. The a cell and the a cell each encodes cell-type-specific regulators: a cells make the regulatory protein a1, and alpha cells make the proteins alpha1 and alpha2. A fourth regulatory protein, called Mcm1, is also involved in regulating the mating-type-specific genes (and many other genes) and is present in both cell types which shows Combinatorial Control.
The arrangement of regulators at the promoters of a-specific genes and a-specific genes is
cell type: |
gene regulatory proteins: |
target genes: |
1.a cell (haploid) |
a1 Mcm1 |
aSG alphaSG |
2.αlpha cell (haploid) |
alpha 1 alpha 2 Mcm2 |
hSG |
3.a/αlpha cell (diploid) |
a1 Mcm2 alpha2 |
#Question id: 12234
#Unit 10. Ecological Principles