Topic 5.5 Classification

Question 1

5.5.1 Outline the binomial system of nomenclature.

Answer 1

• Genus written first and capitalised (Homo)
• Species follows and is written in lower case (Homo sapiens)
• Some species may also have a sub-species designation (Homo sapiens sapiens)
• Should be underlined when handwritten, italicized when typed

Question 2

5.5.2 List seven levels in the hierarchy of taxa – kingdom, phylum, class, order, family, genus and species, using an example from two different kingdoms for each level.

Answer 2

King Phillip Comes Over For Great Sex

Kingdom Phylum Class Order Family Genus Species

e. g. Animalia, Chrodata, Primates, Hominidae, Homo, sapiens
e. g. Plantae, Angiospermophyta, Dicotyledoneae, Ranales, Ranunculacae, Ranunculus, acris

Question 3

5.5.3 Distinguish between the following phyla of plants, using simple external recognition features: bryophyta, filicinophyta, coniferophyta, and angiospermophyta

Answer 3

Bryophyta

• no ‘true’ leaves or roots
• spores produced in capsule at end of stalk
• anchored by rhizoids
• e.g. mosses

Filicinophyta

• leaves, roots & non-woody stems
• spores in sporangia on underside of leaf
• large leaves (fronds) that are divided into leaflets
• e.g. ferns

Coniferophyta

• leaves, roots & woody stems
• seeds found in cones
• leaves usually narraw with thick waxy cuticle
• e.g. conifers & pine trees

Angiospermophyta

• leaves, roots & stems (both woody & non-woody)
• seeds found in fruits
• have flowers
• e.g. flowering plants and grasses

Question 4

5.5.4 Distinguish between the following phyla of animals, using simple external recognition features: porifera, cnidaria, platyhelminthes, annelida, mollusca, arthropoda

Answer 4

Porifera

• asymmetrical
• no mouth/anus
• pores through body
• e.g. sponges

Cnidaria

• radial symmetry
• mouth but no anus
• may have tentacles with stinging cells
• e.g. jellyfish

Platyhelminthes

• bilateral symmetry
• mouth but no anus
• flat, softened body
• e.g. flatworms & tapeworms

Annelida

• bilateral symmetry
• mouth and anus
• segmented body, bristles often present
• e.g. earthworm

Mollusca

• bilateral symmetry
• mouth and anus
• muscular foot and mantle; may have shell
• e.g. snails and slugs

Arthropoda

• bilateral symmetry
• mouth and anus
• jointed appendages, exoskeleton
• e.g. spiders, insects, crustaceans

Question 5

5.5.5 Apply and design a key for a group of up to eight organisms.

Answer 5

Example

1. Simple undivided leaves —— Elodea​

Leaves forked or divided into segments —— 2

2. Leaves forked once or twice to form two or four segments —— Ceratophyllum

Leaves divided into more than four segments —— 3

3. Leaves divided into many flattened segments —— Cabomba
Leaves divided into many filamentous segments —— Myriophyllum