3.5 Cell specialisation and organisation Flashcards
What is cell specialisation?
The process by which the identical cells in an embryo becomes suited to its function.
- each cell has identical genes, but expresses different ones depending on the function
- they may vary in shape or in the number of different organelles they possess.
EG: muscle cells have lots of mitochondria, white blood cells have lots of lysosomes.
What is a tissue?
a group of similar cells which perform a specific function.
Describe epithelial tissue.
- lines organs and often has protective/secretory functions.
- can be made up of thin, flat cells like the tissue which line organs
- can be ciliated, like the tissue which line ducts such as the trachea.
Describe the xylem tissue.
- found in plants
- made up of lots of similar cell types
- transports water and minerals
- gives mechanical support.
What is an organ?
A combination of tissues which are coordinated to perform a variety of functions
Which tissues make up the stomach?
- muscle tissue- to churn and mix contents
- epithelium- to protect stomach wall and produce secretions
- connective tissue- to hold together other tissues
What tissues make up a leaf?
- palisade mesophyll- made up of leaf palisade cells which carry out photosynthesis
- Spongy mesophyll- adapted for gas diffusion
- epidermis- protects leaf and allows diffusion
- phloem- transport organic materials away
- xylem- transport water and ions to the leaf
What is an organ system?
organs which work together as a single unit.
Describe the digestive system.
- digests and processes food
- made up of salivary glands, oesophagus, stomach, duodenum, ileum, pancreas, liver
Describe the respiratory system.
- used for breathing and gas exchange
- made up of trachea, bronchi, lungs
Describe the circulatory system.
- pumps and circulates blood
- made up of heart, arteries, veins
