IGCSE Biology - Movement In and Out of cells

Plasmolysed

When so much water has left the plant cell by osmosis that the cell membrane peels away from the cell wall.

Flaccid

When water has moved out of a plant cell by osmosis. The cell wall is touching the cell membrane but not exerting any force upon it.

D

Which diagram shows the appearance of a cell has changed after being immersed in a concentrated sugar solution for a short time?

C

Why does a red blood cell burst when placed in water? A) Dissolved substances diffuse into the cell. B) Dissolved substances diffuse out of the cell. C) Water moves into the cell by osmosis. D) Water moves out of the cell by osmosis.

Lose water by osmosis

Would plant cells immersed in a concentrated salt solution gain or lose water by osmosis?

Gain water by osmosis

Would plant cells immersed in a dilute solution gain or lose water by osmosis?

D

Osmosis is the passage of ...1... molecules from a region of their higher concentration to a region of their lower concentration through a ...2... permeable membrane. Which words fill gaps 1 and 2?

active transport

Root hair cells use this method of transport to absorb mineral ions like nitrate and magnesium from the soil.

osmosis

Root hair cells use this method of transport to absorb water from the soil.

B

Some red blood cells were placed in distilled water and others were placed in three salt solutions of different concentrations. Which diagram shows the appearance of a cell has changed after being in the distilled water?

B

The diagram shows part of an alveolus and part of a nearby capillary. The arrows show the direction of movement of carbon dioxide and oxygen. By which process do these gases move? A) conduction B) diffusion C) osmosis D) transpiration

Concentration gradient

The difference in concentration between two areas

C

The dots represent molecules of a gas in four tubes. In which tube do more molecules move from X to Y than in the opposite direction?

A and D

The dots represent molecules of a gas in four tubes. In which tubes will there be no net diffusion?

Active transport

The movement of a substance across a membrane from a low concentration to a high concentration, against the concentration gradient, using energy from respiration.

Diffusion

The net movement of a substance from an area of high concentration to an areas of low concentration down a concentration gradient.

Osmosis

The net movement of water molecules from a dilute solution to a concentrated solution through a partially permeable membrane.

Carrier protein

These proteins are involved in active transport

Turgid

This describes a plant cell which is full of water after water has moved in by osmosis. Plant cells are normally in this state so that they can provide support and shape to the plant.