Cellular Organisation Flashcards
Why do cells differentiate into different cells?
To be more suited to their function, to carry it out more efficiently
How does a cell differentiate?
Every cell contains genes needed for it develop into any cell. Different genes are switched on (expressed) in different cells.
How do cells vary, once differentiated?
- in shape, size and number of organelles they contain
What is a tissue?
A collection of similar cells that perform a specific function.
Give 2 examples of tissues
- epithelial; line the surfaces of organs and have protective function
- xylem; used to transport water and give mechanical support
What is an organ?
a combination of tissues that are coordinated to perform a variety of functions, but usually have 1 major function
Give 2 examples of organs, and their various tissues that make them up
Stomach:
- muscle to churn food
- epithelium to protect wall and produce secretions
- connective tissue to hold together tissues
Plant leaf:
- palisade mesophyll and spongy mesophyll
- xylem and phloem
- epidermis
why is an artery described as a tissue but a capillary is not?
An artery is made up of many tissues; epithelial, connective and muscle. A capillary is only made up of epithelium
What is an organ system?
- a group of organs that work together as a single unit to perform particular functions more efficiently
Give 3 examples of organ systems
- digestive system
- respiratory system
- circulatory system
