Classification of Living Things Why classify Think of

Classification of Living Things

Why classify? Think of three examples where we group things. Why do we group these things?

What is classification? Classification is the grouping of living organisms according to similar structures and functions.

Early classification systems Aristotle grouped animals according to the way they moved

HIERARCHIAL SPECIES CLASSIFICATION Increasing level of specificity RANK: level in the hierarchy TAXON: names of the levels TAXONOMY: the use of taxons to classify species

The modernbyclassification system : Developed Carolus Linnaeus Consists of 7 levels: Domains Kingdoms Phyla Classes Orders Families Genera Species

Helpful way to remember the 7 levels King Philip Came Over For Grape Soda. King Philip Came Over For Green Skittles.

Binomial Nomenclature Developed by Carolus Linnaeus Two-name system: First name is the organism’s genus Second name is the organism’s species

What rules are used to write scientific names? The first letter of the genus is ALWAYS capitalized The first letter of the species is NEVER capitalized Scientific names of organisms are always italicized or underlined

Using the Classification System Field guides help identify organisms. -they highlight differences between similar organisms (like trees) Taxonomic Key (Dichotomous Key) -paired statements that describe the physical characteristics of different organisms

IDENTIFYING SPECIES Three concepts for ways to define a species No consensus on definition 1) Morphological 2) Biological 3) Phylogenetic

1) MORPHOLOGICAL: Physical descriptions and measurements ADVANTAGE: simple DISADVANTAGE: difficult to distinguish bw variations within a species and bw species

2) BIOLOGICAL Ability to produce fertile offspring ADVANTAGE: Testable for existing species DISADVANTAGE: Not testable for extinct or asexual species

3) PHYLOGENETIC: Evolutionary relationship, DNA ADVANTAGE: living or extinct species DISADVANTAGE: not all evolutionary histories are known

TWO TYPES OF CELLS • All living things are made of cells: • TWO TYPES: 1) Prokaryotic cells (“lacks nucleus”, ancient) Ex: Bacterial cells 2) Eukaryotic cells (“true nucleus”, more advanced) Ex: Animal cells and plant cells

WHAT’S THE DIFFERENCE?

PROKARYOTIC CELLS First type of cell on Earth! NO nucleus (DNA is floating around) NO mitochondria NO chloroplast (or any membrane-bound organelle) Smaller in size Small piece of DNA (1 chromo) ALL bacterial cells are prokaryotic

DOMAINS 1) Archaea (prokaryotic cells) 2) Bacteria (prokaryotic cells) 3) Eukarya (eukaryotic cells)

The 6 Kingdoms 1. Plants 2. Animals 3. Protists 4. Fungi 5. Eubacteria 6. Archaebacteria

How are organisms organised into kingdoms? Cell type, complex or simple Their ability to make food The number of cells in their body

Archaebacteria discovered in 1983 in a spot deep in the Pacific Ocean where hot gases and molten rock boiled into the ocean from the Earth’s interior they are unicellular (one cell) organisms found in extreme environments such as very high temperatures, no oxygen, or in highly acidic environments Pyrococcus CH 1, discovered thriving on a mid-Atlantic ridge within a temperature range of 80 to 105°C an

Eubacteria complex and single celled most common bacteria are classified in their own kingdom because their chemical makeup is different Staphylococcus aureus (found in the nose) Streptococcus pyogenes (Strep throat is a common disease in children )

Fungi Mushrooms, mold and mildew Most fungi are multicellular and consist of many complex cells

Protista slime molds and algae include all microscopic organisms that are not bacteria, not animals, not plants and not fungi most are unicellular they are not classified in the Archaebacteria or Eubacteria kingdom because, unlike bacteria, protists are complex cells

Plantae Plants are multicellular most don't move, although gametes of some plants move using cilia or flagella Organelles: nucleus, chloroplasts are present, and cell walls are present photosynthesis they are autotrophs

Animalia Animals are multicellular they move with the aid of cilia, flagella, or muscular organs based on contractile proteins. Organelles: a nucleus, but no chloroplasts or cell walls. animals acquire nutrients by ingestion they are heterotrophs

REVIEW All living things are made of cells Prok (no memb) and Euk 3 Domains: 1) Archaea (prok): extremophiles, primitive 2) Bacteria(prok): evolved more recently 3) Eukarya (euk): more recent organisms Bacteria are classified by shape and structure: Structure: Gram +/ Shape: Bacillus, coccus, spirilla, cilia, flagella, pseudopods 6 Kingdoms: Archaea/Bacteria/Protista/Fungi/Plantae/Animalia

Classifying Living Things We put livings things into two large groups: Animals Plants

Animals are spilt into two major groups: Vertebrates Invertebrates

Vertebrates These are animals with a backbone. There are five groups of vertebrates: Amphibians Birds Fish Mammals Reptiles

Amphibians Have moist skin Lay jelly coated eggs in water Lives on land water

Birds Have feathers and hollow bones Lay hard shelled eggs Warm blooded

Fish Have wet scales Lays eggs in water Lives in water

Mammals Have hair and produce milk Give birth to live offspring (no eggs) Warm blooded

Reptiles Have dry scales Lay leathery shelled eggs Cold blooded

Summary of Vertebrates

Invertebrates These are animals without a backbone There are eight groups of invertebrates Molluscs Flatworms Annelids Roundworms Sponges Echinoderms Cnidarians Arthropods

Molluscs Crawl on a single fleshy pad. Can have a shell

Flatworms Have flat worm like bodies

Annelids Have round worm like bodies Have bodies divided into segments

Roundworms Have long thin round worm like bodies Have bodies with no segments

Sponges Have bodies made of loosely joined cells

Echinoderms Have bodies divided into five parts Have spiny outer covering

Cnidarians Have thin sack like bodies Have tentacles

Arthropods Have lots of legs and segmented bodies. There are four group of arthropods: Arachnids Centipedes & Millipedes Crustaceans Insects

Arthropods Arachnid Have four pairs of legs. Have bodies divided into two sections

Arthropods – Centipedes & Millipedes Have long thin bodies and pairs of legs on each of their many body sections

Arthropods - Crustacean Have five-seven pairs of legs First pair often used as pincers Bodies covered in shell

Arthropods Insects Have three pairs of legs Bodies divided into three sections Often have wings

Taxonomic Key 1 a Fruits occur singly. . . . Go to 3 1 b Fruits occur in clusters of two or more. . . Go to 2 2 a Fruits are round. . . . Grapes 2 b Fruits are elongate. . . . Bananas 3 a Thick skin that separates easily from flesh. . . Oranges 3 b Thin skin that adheres to flesh. . . . Go to 4 4 a More than one seed per fruit. . . . Apples 4 b One seed per fruit. . . Go to 5 5 a Skin covered with velvety hairs. . . . . Peaches 5 b Skin smooth, without hairs. . . . Plums What steps would you use to identify a peach?