U2. Organisation of organisms Flashcards
Name the organisation level of living things
Organelle, cell, tissue, organ, organ system, organism
Define organelle
a structure in a cell
Define cell
A functional basic unit of an organism
Define tissue
A group of cells with similar structures, working together to perform a shared function
Define organ
A structure made up of a group of tissues, working together to perform specific functions
Define organ system
A group of organs with related functions, working together to perform body functions
Define organism
All organ systems working together to form a biological entity
How are new cells produced?
by division of exsisting cells
What are common in all living cells?
- cytoplasm
- cell membrane
- DNA as a genetic material (cytoplasm/enclosed in nucleus)
- enzymes for respiration (release energy)
- ribosomes (making protein)
Functions of cytoplasm
Contains enzymes for chemical reactions
- supports cell structures
- site of many chemical reactions
- contains water and many solutes
- e.g respiration
- found in all cells
Where is cytoplasm found and what does it contain?
enclosed by cell membrane
contains cell organelles (mitochondria, nucleus)
Functions of cell membrane
Controls entry and exit in and out of the cell
- present in all cells
Functions of ribosomes
Make proteins from amino acids using the information on mRNA (protein synthesis)
- present in all cells
- only visible under electron microscope
Functions of nucleus
Enclose DNA, controls cell activities
- not present in prokaryotes
What is the nucleus surrounded by and what does this do?
The large nucleus is surrounded by a nuclear membrane to separate it from the cytoplasm