Intervention Bio P2 B3

Active transport is the movement of

• molecules from a region of their higher concentration to a region of their lower concentration.

• particles from a region of lower concentration to a region of higher concentration using energy from respiration.

• urine by relaxation of a sphincter muscle in the bladder.

• water through a partially permeable membrane from a more dilute to a more concentrated solution.

The diagram shows an experiment to demonstrate the movement of molecules. After one hour, the water in the beaker turned red. What is the most likely reason for this colour change?

• Molecules of red ink move through the membrane by diffusion.

• Molecules of red ink move through the membrane by osmosis.

• Molecules of water move through the membrane by diffusion.

• Molecules of water move through the membrane by osmosis.

Why does oxygen diffuse into the blood from an alveolus in the lungs?

• The oxygen concentration in the alveolus is greater than the carbon dioxide concentration in the blood.

• The oxygen concentration in the alveolus is greater than in the blood.

• The oxygen concentration in the blood is greater than in the alveolus.

• The oxygen concentration in the blood is greater than the carbon dioxide concentration in the alveolus.

The diagram shows water and sugar molecules on either side of a partially permeable membrane. What happens during osmosis?

• More sugar molecules pass through the membrane from X to Y than from Y to X.

• More sugar molecules pass through the membrane from Y to X than from X to Y.

• More water molecules pass through the membrane from X to Y than from Y to X.

• More water molecules pass through the membrane from Y to X than from X to Y.

A jar of air was placed upside down on top of a jar containing a brown gas as shown. Which process has taken place?

• diffusion both upwards and downwards

• diffusion downwards only

• diffusion upwards only

• diffusion and osmosis

Which statement describes how young plants are supported?

• the pressure of water inside the cells pressing outwards on the cell membranes

• the pressure of water inside the cells pressing outwards on the cell walls

• the pressure of water passing from the roots through the phloem

• the pressure of water passing from the roots through the xylem

The diagram shows a test-tube containing clear jelly. A drop of blue ink is injected into the middle of the jelly. The blue colour of the ink spreads throughout the jelly. By which process does the blue ink spread through the jelly?

• active transport

• catalysis

• diffusion

• osmosis

Which diagram shows the changes in appearance of a plant cell when it remains in a concentrated sugar solution for thirty minutes?

• 
• 
• 
• 

The diagram shows a fish in a pond. Why does oxygen diffuse from the air into the water before reaching the fish?

• Oxygen is more concentrated in the air than in the water.

• Oxygen is more concentrated in the water than in the air.

• Oxygen is needed by the fish for aerobic respiration.

• Oxygen is needed by the fish for anaerobic respiration.

Which structure provides the best surface for diffusion?

• atrium

• bronchioles

• ileum

• trachea