Glossary:

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• Cells

Living organisms are made of cells. Some organisms are only one cell big.

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• Eukaryotic

Cells that contain organelles (than have membranes). E.g. Animal and Plant.�

• Prokaryotic

Cells that don’t contain organelles e.g. Bacteria.

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• Organelles

These are parts of a cell that carry out specific roles (e.g. Nucleus).

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• Differentiation

This is the process by which cells take on certain roles.

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• Specialisation

This is how cells are adapted to carry out a specific role/task.

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• Microscopy

This is the use of a microscope to magnify objects that otherwise would not be visible to the naked eye.

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• Magnification

This is the process of increasing the size of an object via the use of lenses of different strengths.

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• Cell cycle

All cells replicate to form new cells. This process is called the cell cycle.

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• Mitosis

This is a stage of the cell cycle in which key components, including DNA replicates.�

• Chromosomes

These are the molecules that contain DNA within the cell Nucleus.

Cells are either classified as Eukaryotic or Prokaryotic

Those with true membrane bound organelles (e.g. Nucleus/Mitochondria) are Eukaryotic.

Those without these organelles are said to be Prokaryotic.

Bacteria are good examples of Prokaryotic cells.

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Eukaryotic cells include�Animal and Plant cells

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They both contain membrane �bound organelles, however�Plants have some unique to�them

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Specialised Cells – Cells have a specific role to perform. As such they need to have key organelles within them to help them to achieve this. They may also have a specific physical adaptation to help them with their role.

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Magnification

To allow us to see things that are too small to see with the naked eye we can magnify them. This means you increase their size by a specific factor (e.g x10 or x 20)

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B1: Cell Biology

Microscopy

1. To view an object under a microscope a microscope slide must first be prepared. This is where a thin piece of tissue, or sample of cells, is placed on a glass slide, and stained. The light is turned on.
2. The slide is clipped to the stage, and then the objective lens is turned to x10.
3. Using the coarse focusing wheel, the sample is observed until it is clearly visible. �������������
4. You can then increase the magnification by changing the objective lens. If you change it x 20 it means you’ve doubled the magnification.
5. The eye piece lens you look through during this has a magnification of x10. This means that your total magnification is 10 times whatever the objective lens is. (e.g 10 x 20 = x200)

Magnification equation

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The cell cycle

Stage 1

Cell growth and DNA replication

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Stage 2

Nucleus divides, and chromosomes move to each end of the cell

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Stage 3

Membrane divides, creating identical cells

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Stem Cells

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Stem cells are unspecialised cells that have the capacity to turn into any other cell type.

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They can be found in adults from blood and bone marrow

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The best ones come from Embryo’s, however their use has ethical implications

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Movement across

A membrane

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Substances need

to get in and out �of cells. This can

Be done by…

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B1: Cell Biology