5.5 CLASSIFICATION

Ms. TRS

FUNGI –eukaryotic, multicellular ( except yeast), saprotrophs

PROKARYOTA ( bacteria – unicelluar prokaryotic ,auto- or heterotrophic forms)

PROTOCTISTA – unicellular eukaryotic heterotrophs with a few exceptions

PLANTAE (eukaryotic, multicellular autotrophs)

ANIMALIA ( multicellular heterotrophs)

5.5.1: Binomial system of nomenclature

• Designed by Carolus Linneaus in 18th century• Every species has a Latin name, made up of two

parts• First part is the name of the Genus• Second part specifies the species• Name should be printed in italics (underlined if

hand written) and first part capitalized• Example• Humans are Homo sapiens

BINOMIAL SYSTEM OF NOMENCLATURE:

Two named Naming system

Homo sapiensFirst name = capital letter; if typed always in italics; if handwritten always underlined

GENUS SPECIES

Developed by Carl Linnaeus – a Swedish Bottanist (1707 – 1778)

Exam question:Outline the binomial system of nomenclature(4)

Answer:

Called binomial because two names are used;First name is genus, with first name being a capital;Second name is species, with no capital;Italics are used when the name is printed; The name is underlined if it is handwritten;

Discuss the value of classifying organisms [2]

Species Classification - It is easier to find out which species an organism belongs to when you have other organisms to compare it to; You can make assumptions about characteristics of a species in general;Evolutionary links, you can make assumptions about traits of a common ancestor; You can also predict how they evolved.

Which of these two reef sharks are most closely related and why?

Carcharhinus melanopterus

CarcharhinusPerezi

TriaenodonObesus

Same genus, different species

5.5.2: Hierarchical system of classification

• The Hierarchical system has seven levels called taxons (plural: taxa)

• Each taxon can contain one or more of the sub-group below it• The seven level hierarchies of taxa are:

1. Kingdom2. Phylum3. Class4. Order5. Family6. Genus7. Species

• To remember the taxa in the correct order:

• King Philip Came Over For Good Spagetti

Kingdom Animalia PlantaePhylum Chordata AngiospermaeClass Mammalia DicotyledoneaeOrder Primate Rosales

Family Hominidae Papilionaceae

Genus Homo Pisum

species sapiens sativum

5.5.3: Distinguish between Plant Phyla

• Kingdom: Plantae• Characteristics:

• Photosynthetic• Chlorophyll• Cellulose cell wall• Permanent vacuoles• Stores starch

• Classification of the major plant phyla is based on external observable structures

• Main points: 1.roots, leaves and stems; • 2. vascular tissue; • 3. reproduction

4 Major plant phylaBryophyta – Filicinophyta Coniferophyta Angiospermophyta

– -

PLANTAE

Bryophyta(mosses)

No roots or stemSmall leaf like

structures, rhizoids for roots

No vascular tissueReproduce using spores

Spores are formed in capsules

Filicinophyta(ferns)

Roots, leaves and short stems

Leaves divided into sections and curled

Have vascular tissueReproduce using spores produced

under leaves

Coniferophyta(conifers)

Woody treesHave narrow needles for

leaves with thick waxy cuticle

Have vascular tissueReproduce using seeds in

cones, not enclosed in fruits

Wind pollinated

Angiospermophyta(flowering plants)

Roots, leaves and stems, stem can be woodyHave vascular tissue

Produce flowersSeeds are enclosed in

ovaries that form fruitsSeeds dispersed through

fruits

Division Bryophyta

• No true roots, stem or leaves

• Have rhizoids instead of roots

• No vascular tissue – must absorb water from surface instead of absorbing from roots

• Reproduce by spores made in capsules

• Moss are commonly found in damp, shady areas

Filicinophyta (ferns)

• Have true roots, stem and leaves. Stem not woody in most of the plants

• First group of vascular plants:– Xylem and phloem

transport resources between distant organs.

Reproduce by spores made in sporangia under leave

Seen in tropical and temperate forests

Coniferophyta• Includes ~ 550 species of large trees

with thick woody stem including pines, firs, spruces, and redwoods

• Most conifers have needles or narrow leaves modified to prevent water loss and thick waxy cuticle

• Have vascular tissue

• All produce seeds in cones• Seeds are not enclosed in ovary or

fruit.• Most use wind pollination for

reproduction.• Almost all conifers are evergreens

Angiospemophyta• True flowering plants• Angion means “container,” –

seeds are enclosed in fruits. During development, the ovule becomes seed and the ovary becomes fruit.

• Includes ~ 235,000 species of flowering plants

• May rely on wind, birds, insects, and even mammals for pollination and reproduction.

• Have vascular tissue

IB exam questions

Plants are a diverse group of eukaryotic organisms. Describe the different characteristics of the bryophyta, filicinophyta, coniferophyta and angiospermophyta. 9 marks

Outline the structural differences that characterize bryophytes, filicinophytes, coniferophytes and angiospermophytes. 9 marks

Bryophyta:No roots, have rhizoids, simple stem and leavesNon vascularProduce spores in capsule

Filicinophyta:Have roots, stems and leaves, leaves are large and divided into sectionsHave primitive vascular tissueReproduce by making spores in sporangia on the underside of leaves

Coniferophyta:Have woody stem, narrow needle like leaves with thick waxy cuticleHave well developed vascular tissueProduce seeds in conesSeeds are not enclosed in fruits

Angiospermophyta:Produce flowersFlowers have ovules in ovariesSeeds are enclosed in fruits.( ovules form seeds and ovary forms fruit)

5.5.4 Distinguish between the major invertebrate phyla using external features

Features of invertebrate phylaPhylum Symmetry Digestive tract Segmentation Other features

PoriferaExample:

CnidariaExample:

PlatyhelminthesExample

AnnelidaExample:

MolluscaExample:

ArthropodaExample:

ANIMALIA

Invertebrates

Porifera(sponges)

No symmetryNo mouth or anusNo segmentation

Water flows in and out of body through pores

Cnidaria(jellyfish/coral

polyps)

Radial symmetryTentacles/ One opening to gut

No segmentationStinging cells - nematocysts

Platyhelminths(flatworms)

Bilateral symmetryOne opening to gutNo segmentation

Gas exchange over large surface areaAnnelida

(segmented worms)

Bilateral symmetryD.T:With Mouth and anus

Very segmentedBristles on body/Mollusca

(snails/clams/octopuses)

Usually bilateral/ no segmentationDT: with Mouth and anus

Most of them have a calcium shell covering soft bodyArthropoda

(insects/spiders/crustaceans, millipedes)

Bilateral symmetryD.T : with Mouth and anus

segmentedJointed legs + exoskeleton of chitin

Phylum Porifera

• Includes sponges

• Characteristics: no body symmetry, no tissues, no organs; hermaphrodites; filter feeders; water moves in and out of the body through pores; sessile 5.5.4

Phylum Cnidaria

• Includes corals, jellyfish, and sea anemone

• Characteristics: stinging cells for food and protection; one-way digestive tract; radial symmetry; no segmentation drifters or sessile 5.5.4

Phylum Platyhelminthes

• Includes flatworms like planaria, flukes, and tapeworms.

• Characteristics: distinct head region (cephalization); bilateral symmetry; most are parasites; one-way digestive tract; no heart or lungs; flat shape - why?

5.5.4

Phylum Annelida

• Includes earthworms, marine worms, and leeches.

• Characteristics: segmented; bilaterally symmetrical; well developed nervous, digestive, and circulatory systems; two-way digestive system.

5.5.4

Phylum Mollusca

• Includes snails, clams, octopus and squids.

• Characteristics: bilateral symmetry; two-way digestive tract; exoskeleton (shells) of calcium carbonate; soft bodies; most are aquatic

5.5.4

Phylum Arthropoda• Includes insects,

arachnids (spiders), and crustaceans

• Characteristics of all arthropods: exoskeleton made of chitin; jointed appendages; segmented body; bilateral symmetry, open circulatory system

• Molting – process of shedding and exoskeleton and growing a new one to grow larger.

Dichotomous Key

• A dichotomous key is a method used to identify organisms according to their physical traits based on a system of answering yes or no questions about an organism. Through a process of elimination the organism is identified.

• Visible features are used• Questions should be unambiguous• Each question should divide the organisms into two

distinct groups• Identification game: http://www.scenicoregon.com/webanic/pages/animals.html

IB exam questions

• Which phylum does sponges belong to?

• What is the important feature of flat worms?