Unequal crossing over during Prophase I can result in one sister chromosome with a deletion and another with a duplication. A mutated form of hemoglobin, known as hemoglobin Lepore, is known in the human population. Hemoglobin Lepore has a deleted set of amino acids. If it was caused by unequal crossing over, what would be an expected consequence?

#Question id: 2218

#Unit 2. Cellular Organization

Human alkaline phosphatase protein is attached to the plasma membrane by a GPI anchor. In an experiment you treat cells with each of the following enzymes and find one of them inhibits the activity of the protein because it releases it into the extracellular matrix. Which specific enzyme led you to conclude that this anchor on alkaline phosphatase was both necessary and sufficient for binding the protein to the membrane where it can perform its normal activity?

#Question id: 2219

#Unit 2. Cellular Organization

Cholesterol and phospholipids are transported between organelles by

i. Golgi-dependent mechanisms.

ii. incompletely characterized vesicle populations.

iii. direct contact between membranes and, to some extent, small, soluble lipid-transfer proteins.

Which of the following statements are correct?

#Question id: 2220

#Unit 2. Cellular Organization

Cell membranes have distinct inside and outside faces. Which of the following statements is the most likely explanation for the membrane's asymmetrical nature?

#Question id: 2221

#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.

At the beginning of the U-tube experiment illustrated above, which of the following statements is true?

#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: 2223

#Unit 2. Cellular Organization

Five dialysis bags, constructed of a type of membrane that is permeable to water and impermeable to sucrose, were filled with various concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10-minute intervals, the bags were massed (weighed), and the percent change in mass of each bag was graphed.

 Which line in the graph represents the bag that contained a solution isotonic to the 0.6 M solution at the beginning of the experiment?