Brodie's+Work

=__My Glossary Page__=

__﻿__ =__What is an Organism?__= An organism is an individual living thing. It can be either virus, fungi, bacteria, animal or plant.

=__History of Science__=

How did early civilizations explain biological diversity?
Biological diversity (the huge variety of different organisms that exist on Earth) was explained by early philosophers as that they were created by a surpreme being or god figure and that they were immutable (they could not change).

=__Classification__= The process of organising organisms into groups based on predetermined criteria is called classification. The classification of living things is said to be a strong, multilevel classification. Strong, because the scheme gives predictable results. Multilevel because major groupings may be further subdivided into smaller, subgroups. The criterion we use to assign organisms to groups is the closeness of the evolutionary relationships between members of the group. This is usually ovserved by looking at the number of features shared by organisms when we compared them. Features that might be used when looking to group organisms could include:
 * 1) Physical structures (e.g. anatomy of bones, teeth, organs etc)
 * 2) Biochemistry (e.g. protein similarities)
 * 3) Manner of development
 * 4) Behavioural characteristics
 * 5) Similarities in DNA

=__Hierarchies of Organisation__= Organisms have the following levels of organisation:
 * 1) Atoms
 * A unit of matter and the smallest unit of an element, having all the characteristics of that element and consisting of a dense, positively charged nucleus surrounded by a electrons. Example: Calcium.
 * 1) Molecules
 * A molecule is two or more atoms that have combined chemically to form and become a single species. Example: H ² O.
 * 1) Cells
 * A self replicating unit that may either be part of a multicellular organism or a be itself a unicellular organism. Example: Bacteria.
 * 1) Tissues
 * Any distinct type of material that an animal or plant is made from. Tissue contains specialized cells. Example: Heart Tissue.
 * 1) Organs
 * A group of tissues that can perform together a function or variety of functions. Example: Kidney.
 * 1) Organ systems
 * A group of organs working together to do certain tasks. Example: The Human Nervous System.