What is diffusion?
Diffusion is a process whereby molecules move from areas of their higher concentration to areas of their lower concentration.

When will it stop?
It will stop when all the molecules are evenly dispersed.

Do molecules even stop moving?
Molecules never stop moving. They are always moving because of their kinetic energy.

What are the factors that determine the rate of diffusion?
Temperature, size of molecules and the steepness of the concentration gradient.

Can you name some examples of diffusion in a living organism?
1. Diffusion takes place when animals breathe in oxygen and that oxygen is distributed to all cells in that animal. Carbon dioxide in turn is also diffused from the cells into the lungs to be breathed out.

2. Diffusion takes place when a plant takes in carbon dioxide and gives out oxygen during photosynthesis.

These are the procedures of a very fun experiment I conducted in class.

	Procedures
1.	Fold the paper towel into two to make it a 2-ply piece of paper.
2.	Cut it into 3 strips of about 30x20mm and briefly soak them in the cabbage juice.
3.	Remove immediately once the paper turns light purple.
4.	Spread them open and leave aside to dry on the white tile.
5.	Cut your agar block to the following specifications: a.     3 pieces of 5x5x5mm b.     1 piece of 5x5x20mm c.      1 piece of 10x10x10mm
6.	Label your petri dish accordingly based on the solutions that are assigned to you.
7.	Immerse ONE piece of agar of size 5x5x5mm, 5x5x20mm and 10x10x10mmi in lemon juice or baking powder solution.
8.	Record the time it takes for each of the agar to turn uniformly into a different colour in table 1 below.
9.	Immerse the 2 other pieces of 5x5x5mm agar into each of the 2 remaining liquids.
10.	Observe the colour change and record the results in table 2.
11.	Introduce a few drops of each of your 3 solutions onto a different strip of the cabbage juice soaked 2-ply paper towel.
12.	Observe the colour change and record the results in table 2.
13.	Transfer 2cm3 of each of the solution into separate test tubes.
14.	Label the test tube accordingly.
15.	Add an equal volume of cabbage juice to each of these test tubes and record the colour change in table 2. (2cm3 is approximately 2cm in height)

Task 4 and 5: Diagrams of plant and animal cell with labels

Task 6: List briefly the functions of the following organelles: 


1. Nucleus - Control all the activities in the cell.


2. Nucleus membrane - Controls what enters and leaves the nucleus.


3. Chromatin - To package DNA into a smaller volume to fit in the cell, to strengthen the DNA and prevent DNA damage,  and to control gene expression and DNA replication.


4. Cytoplasm - Provides support for the cell.


5. Cell membrane - Controls what enters and leaves the cell.


6. Vacuole - In plant cells, vacuoles tend to be very large and are extremely important in providing structural support, as well as serving functions such as storage, waste disposal, protection, and growth. Vacuoles in animal cells are more commonly used to temporarily store materials or to transport substances.


7. Mitochondria - Provides energy for the cell.


8. Chloroplasts - Contain chlorophyll which aids in photosynthesis.


9. Cellulose cell wall - Protects the cell, provides support for the cell and acts as a filter.

Task 3: List the differences between Plant and Animal cells


A plant cell has a cell wall while an animal cell does not.
Most plant cells have chloroplasts (cells in the roots may not have) but animal cells do not have any.

Task 2: List the similarities of plant and animal cells

Both cells have a nucleus.

Both cells have a cell membrane.

Both cells contain cytoplasm.

Task 1: A table that shows the differences between Prokaryote and Eukaryote Cells.

	EUKARYOTIC CELL	PROKARYOTIC CELL
Cell size:	1-10um	10-100um
DNA wrapping on proteins:	Yes	No
Number of chromosomes:	More than one	One -- but not true chromosome: Plasmids
Nucleus:	Present	Absent
Chloroplasts:	Present (in plants)	Absent
Differentiation:	Multicellular	Unicellular