Levels of organization
Organisms are made from organizations of smaller structures. You need to know the following hierarchy of structures.
Organelles – intracellular structures that carry out specific functions within a cell
Cells – the basic structural and functional unit from which all biological organisms are made
Tissues – a group of specialized cells, which are adapted to carry out a specific function.
Organs – a collection of two or more tissues, which carries out a specific function or functions
Organ Systems – a group of two or more organs
Differences between plant and animal cells
Found in chloroplast
Roughly 50чm long
Roughly 150чm long
No fixed shape
Functions of the Organelles
Cytoplasm – site of chemical reactions in the cell
Cell Membrane – controls what enters / leaves the cell (selectively permeable)
Nucleus – contains nucleic acids, which code for the synthesis of specific proteins. These proteins control all activity in the cell
Mitochondrion – site of respiration
Chloroplast – site of photosynthesis
Cell Wall – made from cellulose. Strengthens the cell and allows it to be turgid
Sap Vacuole – contains the cell sap. Acts as a store of water, or of sugars or, in some cases, of waste products the cell needs to excrete.
That's the end of the topic!
Drafted by Joey (Biology)