IB Biology SL D2.3.3 Osmosis Into Out of Cells Questions
Compare solute concentrations inside and outside animal cells to predict water’s direction across the membrane, and explain no net osmosis at isotonic balance in IB Biology SL D2.3.3.
Syllabus
First assessment 2025
Course
Biology SL
Level
SL
Exam points
Explain how matching osmolarity between cells and their surroundings prevents net osmosis.
Predict whether water enters or leaves animal cells by comparing the surrounding solution’s osmolarity with the cell interior.
IB Biology SL D2.3.3 Osmosis Into Out of Cells Questions question 1
[Maximum number: 3]
The electron micrograph shows the surface membrane of an animal cell.
Explain the reason that animal cells and tissues under investigation must be maintained in solutions with the same osmolarity.
a
to prevent osmosis;
b
cells placed in the incorrect osmolarity might swell/burst/shrink;
c
hypotonic solution would cause water to enter cells/tissues;
d
hypertonic solutions would cause water to leave cells/tissues;
e
water loss would hinder (metabolic) reactions in cell cytoplasm OR distort appearance of the cells (for the investigation);