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Flashcards in Cellular Organisation (UNIT 2) Deck (10):


The process by which each cell becomes specialised in structure to suit the role that it will carry out.


Where do all cells in an organism derive from?

mitotic division of the fertilised egg.
They all have the same genes.


How does a cell differentiate?

Every cell contains the genes needed for it to develop into any one of the many different cells in an organism. But only a few of these genes are are switched on (expressed) in any one cell. Different genes are switched on in each type of differentiated cell. The rest are switched off.



A group of similar cells organised into a structural unit that perform a specific function


Give two examples of tissues. Describe.

-Epithelial tissues, found in animals and consist of sheets of cells. They line the surfaces of organs and often have a protective or secretory function.

-Xylem- Occur in plants and is made up of a number of cell types. Used to transport water and mineral ions throughout the plant and also gives mechanical support.



A combination of tissues that are coordinated to perform a variety of functions.


Explain how the tissues in the stomach work to digest food.

-Muscle to churn and mix the stomach contents,
-Epithelium to protect the stomach wall and produce secretions.
-Connective tissue to hold together the other tissues.


Describe and explain the tissues that make up a leaf(organ)

-Palisade mesophyll made up of leaf palisade cells, that carry out photosynthesis.

-Spongy mesophyll adapted for gaseous exchange

-Epidermis to protect the leaf and allow gaseous diffusion.

-Phloem to transport organic materials away from the leaf.

-Xylem to transport water and ions into the leaf.


Organ systems

Multiple organs working together to perform a particular function.


Describe 3 organ system in humans.

-DIGESTIVE SYSTEM- digests and processes food. Made up of organs that include the salivary glands, oesophagus, stomach, duodenum, ileum, pancreas and liver.

-THE RESPIRATORY SYSTEM- is used for breathing and gas exchange. It is made up of organs that include the trachea, bronchi and lungs.

-THE CIRCULATORY SYSTEM- pumps and circulates blood. It is made up of organs that include the heart, arteries and veins.