Multiple Choice
In the context of passive transport (osmosis), what typically happens to an animal cell placed in a hypertonic solution compared with its cytosol?
23
views
9. Transport Across Membranes
Passive Transport: Diffusion and Osmosis
Multiple Choice
Which of the following is an example of passive transport across a cell membrane?
A
Oxygen moving from a region of higher concentration to lower concentration directly through the lipid bilayer
B
Glucose being pumped into a cell against its concentration gradient by a membrane ATPase
C
Sodium ions entering a cell through a pump that hydrolyzes ATP
D
Bulk uptake of extracellular fluid by endocytosis (pinocytosis)
Verified step by step guidance1
Step 1: Understand the definition of passive transport. Passive transport is the movement of molecules across a cell membrane without the use of cellular energy (ATP), typically moving from an area of higher concentration to an area of lower concentration (down the concentration gradient).
Step 2: Review each option to determine if it fits the criteria of passive transport. Check if the process requires energy or moves substances against their concentration gradient.
Step 3: Analyze the first option: Oxygen moving from a region of higher concentration to lower concentration directly through the lipid bilayer. Since oxygen is moving down its concentration gradient and does not require energy, this is an example of passive transport.
Step 4: Examine the other options: Glucose being pumped against its gradient by ATPase, sodium ions entering via an ATP hydrolyzing pump, and bulk uptake by endocytosis all require energy input, so they are examples of active transport or energy-dependent processes.
Step 5: Conclude that the correct example of passive transport is the movement of oxygen directly through the lipid bilayer down its concentration gradient.
Related Videos
Related Practice
