Specialisation Flashcards
Where do cells come from
All cells in a mature multicellular organisms are produced by mitosis from a fertilised egg
How are cells specialised
Cells are initially all identical in an embryo but as they develop the switching on and off of certain genes takes place, leading to changes in the organelle numbers and shapes of cell
What do all cells contain
All the genes necessary to develop into any cell
Define tissues
A collection of similar cell stat performs specific function
Epithelial tissue
Line surface of organs to perform a protective or secretory function
Eg lining the trachea to push mucus up the throat and line organs where diffusion takes place
Xylem tissue
- Adapted to transport water and ions throughout the plant
- provides plant with mechanical support
Define organs
A combination of tissues that perform one major function
How is the stomach adapted
- muscles churn and mixes stomach content
- connective tissue holds together other tissues
- epithelium tissue produces secretion and protects stomach wall
List the tissue that help the leaf as an organ
- palisade mesophyll
- spongy mesophyll
- Epidermis
- Phloem
- xylem
Function of palisade mesophyll
Carries out photosynthesis
Function of spongy mesophyll
Adapted for gaseous diffusion
Function of empidermis in plants
- protects leaf
- allows gaseous diffusion
Function of phloem
Transport organic material always from plant
Function of xylem
Transport water and ions to the leaf
Define organ system
A number of organs working together
