5.5 Classification

Classification For centuries, humans have been attempting to classify the various species on Earth in order to learn more about the species and their evolutionary history. Classification attempts to group more related species together

Binomial system of Nomenclature A “2 name” naming system that was designed by Carolus Linneaus in the 18th century.

Binomial Symstem of Nomeclature Every species has a Latin name, The first part of the name is the name of the genus, the second part is the species. The name is printed in italics If hand written, underline the name The first letter of the genus is capitalized The first letter of the species is not

Examples: Humans: Homo sapiens GENUS SPECIES Dogs: Canis lupus familiaries SUBSPECIES

Linnaeus’ system was largely based on morphology and is not the best way to classify organisms (Modern methods use evolutionary relationships to classify organisms) However, Linnaeus’ system is still the basis of how we name organisms today.

Hierarchy of Classification We now use a seven level hierarchy of taxa to classify organisms Kingdom Phylum Class Order Family Genus Species

King Phillip Coughs. Oh! Filthy Germs Spread!!!

Kingdoms Kingdoms are the broadest category Originally there were only 2 Kingdoms: Plants and Animals Today, we have identified 5

Modern Kingdoms Kingdom Plantae (plants) Kingdom Animalia (animals) Kingdom Fungi (fungi and moulds) Kingdom Protoctista (protozoa and algae – includes paramicium and amoebas) Kingdom Prokaryotae (bacteria)

Ex: Humans KINGDOM Anamalia PHYLUM Chordata CLASS Mammalia ORDER Prima FAMILY Hominidae GENUS Homo SPECIES sapiens

Ex: Garden Pea KINGDOM Plantae PHYLUM Angiospermae CLASS Dicotyledoneae ORDER Rosales FAMILY Papilionaceae GENUS Pisum SPECIES sativum

Distinguish between the following phyla of plants using simple external recognition features

Bryophyta Mosses and liverworts Small terrestrial plants that do not have true roots, stems or leaves (but may have similar structures) Leaf-like structures arranged in a spiral Usually live in clusters

Filicinophyta Ferns Have true leaves New leaves unroll Have an underground creeping stem (called a rhizome)

Coniferophyta Conifers Woody plants, with a single wooden trunk and side branches Leaves are long thin needles and dark green Produce seeds in cones

Angiospermophyta Angiosperms/ Flowering Plants Have flowers Seeds are in ovaries with become the fruit Leaves usually as a leaf blade and a leaf stalk, with veins visible on the lower surface

Distinguish between the following phyla of animals, using simple external recognition features.

Porifera Sponges Most primitive animals with a simple body Live in water Do not move around No mouth, but have small holes through which water is pumped into body and have be filtered for food before pumping out

Cnidaria Jellyfish and sea anemones Have stinging cells Radially symmetrical Have a gastro-vascular cavity (a hollow space in the centre of the body) with only one opening to the cavity Often have tentacles around the opening

Plathyelminthes Flatworms Soft flattened body with a definite head region Bilateral symmetry Gastro-vascular cavity Usually one opening to cavity Live in water or damp environments Can be free-living or parasitic

Arthropoda Animals with jointed legs Ex: insects, arachnids, crustaceans Exoskeleton made of chitin (a polysaccharide) Segmented body Appendages to each segment At least 3 pairs of legs May be free living or parasitic

Annelida Worms and leeches Bodies of ring-like segments Have a mouth and an anus Live in water or moist soil May be free living or parasitic No legs Bristles from body which help them move

Mollusca Snails, squids, clams, slugs Soft unsegmented bodies May have a shell

Dichotomous Keys Apply and design a key for a group of up to eight organisms. Keys are most commonly used to identify plants, insects, and birds.