cell specialisation and organisation Flashcards
how is a cell specialised?
every cell contains the gene needed for it to develop into any one of the different cells in an organism but only some of these genes are expressed in any one cell, at any one time. Different genes are switched on in each type of specialised cell.
what is a tissue?
collection of similar shells that perform a specific function
where are epithelial tissues found?
they line the surfaces of organs and often have a protective or secretory function
what are some roles of epithelial tissues?
epithelial tissues can be made up of thin, flat cells that lie organs where diffusion takes place, e.g. the alveoli of the lungs
ciliated epithelium that lines a duct such as the trachea- cilia used to move mucus over the epithelial surface
what is the job of the xylem?
used to transport water and mineral ions throughout the plant and also gives mechanical support
what is an organ?
a combination of tissues that are coordinated to perform a variety of functions, although they often have a major function
what tissues is the stomach made of?
-muscle to churn and mix stomach contents
-epithelium to protect the stomach wall and produce secretions
-connective tissue to hold together other tissues
what is an organ system?
organs working together as a single unit known as an organ system
what are 3 examples of organ systems?
-digestive system
-respiratory system
-circulatory system
