1. Chapter 3: Movement of Substances Across the Plasma Membrane
Section A
1. Diagram shows the structure of plasma membrane based on the fluid mosaic model.
a) Name the parts of the plasma membrane labeled X and Y. [2m]
______________________________________________________________________
b) (i) Describe the structure of X and the functions of its parts. [2m]
______________________________________________________________________
______________________________________________________________________
(ii) State the function of Y [1m]
______________________________________________________________________
______________________________________________________________________
c) Substances can move across the plasma membrane by passive transport and active
transport.
(i) Explain two ways by which passive transport can take place [2m]
___________________________________________________________________
(ii) Explain how active transport occurs [2m]
___________________________________________________________________
___________________________________________________________________
d) How do oxygen, glucose and calcium ions are transported across the plasma
membrane? [3m]
______________________________________________________________________
______________________________________________________________________
e) State two differences between passive transport and active transport. [2m]
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________

2. Section B (Open response)
2. The movement of substances across the plasma membrane of the root hair cells
enables the plant to obtain the substances it needs.
a) Explain how
(i) Water in the soil enters the roots of the plant [2m]
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
(ii) Calcium in the soil enters the roots of the plant [2m]
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
The concentration of solution surrounding the cell will influence the function of
the cell. Solutions that are isotonic, hypotonic and hypertonic can affect both plant
cells and animal cells
b) (i) What is the meaning of isotonic, hypotonic and hypertonic? [3m]
______________________________________________________________________
______________________________________________________________________
______________________________________________________________________
(ii) Write a report on the effects of these three solutions on erythrocyte cells. [9m]
(iii)Describe how erythrocyte cells are prevented from being destroyed in the blood.
[4m]
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________
___________________________________________________________________