DP Biology (first assessment 2025)

Test builder »

Question 19M.1A.HL.TZ2.5

Select a Test
Date May 2019 Marks available [Maximum mark: 1] Reference code 19M.1A.HL.TZ2.5
Level HL Paper 1A Time zone TZ2
Command term Determine Question number 5 Adapted from N/A
5.
[Maximum mark: 1]
19M.1A.HL.TZ2.5

The table shows concentrations of potassium ions and sodium ions inside and outside human cells.

[Source: © International Baccalaureate Organization 2019]

 

What explains these concentrations?

A. Potassium ions diffuse in and sodium ions diffuse out.

B. Sodium ions diffuse in and potassium ions diffuse out.

C. Active transport pumps sodium ions in and potassium ions out.

D. Active transport pumps sodium ions out and potassium ions in.

[1]

Markscheme

D

Syllabus sections