- Slides: 21
Why do we classify things? • Classification provides scientists and students a way to sort and group organisms for easier study. • There are millions of organisms on the earth! (approximately 1. 5 million have been already named) Organisms are classified by their: * physical structure (how they look) * evolutionary relationships * embryonic similarities (embryos) * genetic similarities (DNA) * biochemical similarities
UNITY AND DIVERSITY • All living things carry out the life functions. There are many different types of organisms. • In one classification system, there are 2 main groups. In others, there are 3. In the one used by most of the world's scientists, which we will also use, there are 5 main groups. All living things are placed in one of the five KINGDOMS. . . which are the most general group. They are then broken down into smaller groups, then smaller and so on until there is just one. . . SPECIES is the most specific group. . .
• KPCOFGS • Now your turn, create a sentence with the first letter of each word!
• TAXONOMY--the branch of science that classifies and names living things. • NOMENCLATURE--a system for naming things • In biology there is a two-word system that is used to name organisms. It is called BINOMIAL NOMENCLATURE (a two named-naming system). • Carolus Linnaeus devised this in the 1800's using these two subgroups for the name: GENUS & SPECIES (more general) (more specific) • Humans are known as Homo sapiens
The Five Kingdoms MONERA PROTISTA FUNGI PLANT ANIMAL
Organisms are groups among these five kingdoms by: • the presence or absence of a nuclear membrane • unicellular (one cell) or multi-cellular (many cells) • the type of nutrition used by the organism (heterotrophic or autotrophic)
I. Kingdom MONERA • have a primitive cell structure lacking a nuclear membrane—PROKARYOTE • most of this kingdom are unicellular (some exist in multicellular clusters) • two main phyla A) Bacteria (heterotrophic) B) Blue-green algae (autotrophic)
II. Kingdom PROTISTA • has a membrane around the nucleus of the cell— EUKARYOTIC • predominantly unicellular • two main phyla A) Protozoa--animal like nutrition (heterotrophic) ex. paramecia, ameba B) Algae--plant like nutrition (autotrophic) ex. spirogyra
III. Kingdom FUNGI • has a membrane around the nucleus of the cell— EUKARYOTIC • absorbs food from its environment (heterotrophic), does NOT ingest it! • organized into branched, multinucleated filaments ex. bread molds (multicellular) mushrooms (multicellular) yeast (unicellular)
IV. Kingdom PLANTS • has a membrane around the nucleus of the cell— EUKARYOTIC • Multi-cellular organisms • photosynthetic organisms (autotrophic) (photo=light) (synthesis=to make) PHOTOSYNTHESIS=TO MAKE FROM LIGHT
V. Kingdom ANIMAL • largest of 5 kingdoms • has a membrane around the nucleus of the cell— EUKARYOTIC • Multi-cellular • ingests their food (heterotrophic)