B1.1

Question	Answer
Bacterial cell has a Cytoplasm and Membrane surrounded by a cell wall	Cellulose strengthens a cell, a bacterial cell wall has no cellulose in it.
Yeast is a single celled organism. Yeast cells have a Nucleus, cytoplasm, cell membrane and surrounded by a cell wall	Dissolved substances need to pass through cell membranes to get in and out of cells.
Cells are living things; so they need to replace substances that are used up like oxygen and food but remove substances that accumulate like carbon dioxide and waste products. They pass through cell membranes by diffusion.	Diffusion is the spreading of the particles of a gas or of any substance in a solution.
A net movement occurs from a region of high concentration to a region of low concentration. For example, oxygen required for respiration process passes through all membranes by diffusion.	The greater the difference in concentration, the faster the rate of diffusion. For example, Oxygen and Amoeba, there is lots of oxygen outside the amoeba but much less inside because it's being used up in respiration. Rapid diffusion of oxygen into the amoeba through the cell membrane.
Diffusion can take place automatically without need for energy.

Resource summary

	Created by Kyle Campbell over 8 years ago