Systems of classification

Question 1

Classification

Answer 1

The organisation of living organisms into groups based on accepted principles

Question 2

Phylogeny

Answer 2

The study of evolutionary relationships

Question 3

Phylogenetic trees

Answer 3

• Living organisms at tips of branches
• Ancestral species in branches and trunks
• Common ancestors at branch points

Question 4

Taxonomy

Answer 4

Identification and naming of organisms

Question 5

Classification

Answer 5

Grouping organisms/items

Question 6

Hierarchy

Answer 6

A system of ranking in which small groups are nested components of larger groups

Question 7

Taxon

Answer 7

Any group within a system of classification

Question 8

The 3 Domain System

Answer 8

Based on molecular biology techniques, as opposed to observed physical features

Bacteria:

• Prokaryotes
• True bacteria
• Some can be extremophiles

Archaea:

• Prokaryotes
• All extremophiles
• Can survive in extreme environments e.g. temperature, pH, salinity and pressure

Eukaryota:

• All eukaryotes
• Four eukaryotic kingdoms; Animalia, Plantae, Fungi and Protoctista

Question 9

The Taxa

“King Phillip Came Over From Great Spain”

Answer 9

Kingdom:
-Sub-group of a domain e.g. Animalia

Phylum:

• Sub-group of a kingdom e.g. Chordata
• Members have distinct body plans

Class:
-Sub-group of a phylum e.g. Mammalia

Order:
-Sub-group of a class e.g. Primate

Family:
-Sub-group of an order e.g. Hominidae

Genus:
-Sub-group of a family e.g. Homo

Species:

• Sub-group of a genus e.g. Sapiens
• A group of organisms that can interbreed to produce fertile offspring

Question 10

The 5 Kingdom System

Answer 10

Only based on observed physical features, and was used before molecular biology techniques were available:

Animalia:

• Multicellular eukaryotes
• Heterotrophic (Consumes their nutrients)
• No cell wall
• Nervous coordination

Plantae:

• Multicellular eukaryotes
• Photosynthetic
• Cellulose cell wall

Protoctista:

• Single cell eukaryotes
• No tissue differentiation

Fungi:

• Eukaryotes
• Heterotrophic
• Cell walls of chitin
• Have filaments called hyphae
• Reproduce by spores

Prokaryota:

• Prokaryotic cells
• No nuclear envelope
• No membrane bound organelles
• Peptidoglycan cell wall