3.1.1 - Principles of classification

Question 1

What is classification?

Answer 1

Process of sorting living things into groups.

Question 2

What are the 8 heirarchial levels in order?

Answer 2

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 3

What are the 3 domains?

Answer 3

Eukaryotae
Archaea
Bacteria

Question 4

5 kingdoms?

Answer 4

Anamilia
Plantae
Fungi
Protoctista
Prokaryota

Question 5

How are organisms classified in the phylum level?

Answer 5

Based on body design eg. backbone or not

Question 6

How are organisms classified in the class level?

Answer 6

Based on general traits e.g number of limbs

Question 7

How are organisms classified in the order level?

Answer 7

Further division based on specific information e.g dividing wolves and cows.

Question 8

How are organisms classified in the family level?

Answer 8

Closely related genera e.g dogs and cats separated

Question 9

How are organisms classified in the genus level?

Answer 9

Closely related species e.g homo erectus and homo sapiens

Question 10

How are organisms classified in the species level?

Answer 10

Basic unit of classification in which members show little variation

Question 11

2 ways you can write the name of a classified organism

Answer 11

Genus Species (both underlined)
G.Species

Question 12

Explain the evidence that led to the three-domain model of classification replacing the
five-kingdom model.
(3)

Answer 12

The use of techniques such as molecular phylogeny.
Allowed us to see similarities and differences between archaea and bacteria.
Such as membrane structure.

Question 13

Scientists agreed to separate the African elephants into two species based on new
evidence from DNA sequencing.
State how scientists reach agreement on new evidence.

Answer 13

Peer review
Published in journals

Question 14

Describe the information scientists can use to classify an organism as a new species.
(4)

Answer 14

Compare anatomy/morphology
Observe behaviour or the niches they occupy.
Use DNA profiling and bioinformatics
See if they are unable to breed to produce fertile offspring.

Question 15

Explain why it may be difficult to classify a newly discovered organism as a separate
species.
(2)

Answer 15

Some species can interbreed to produce fertile offspring.
Species are evolving over time.
Sexual dimorphism

Question 16

Describe evidence, other than the gel electrophoresis of DNA, that a scientist could use to
establish the evolutionary relationships between species.
(4)

Answer 16

use information about morphology/anatomy.
use of bioinformatics.
Look at the ecological niche and where the species is found.
Using information about the similarities in proteins.