4B - Classification of organisms

Question 1

What is phylogeny?

Answer 1

The study of the evolutionary history of organisms.

Question 2

What have all organisms evolved from?

Answer 2

Shared common ancestors.

Question 3

How can evolutionary relationships be shown?

Answer 3

On a phylogenetic tree.

Question 4

What does phylogeny tell us?

Answer 4

Who is related to who and how closely related they are.

Question 5

What is taxonomy?

Answer 5

The science of classification, it involves naming organisms and organising them into groups.

Question 6

What are the 8 levels of taxonomy?

Answer 6

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 7

What is phylogenetic classification?

Answer 7

A system that attempts to arrange species into groups based on their evolutionary origins and relationships.

Question 8

Can groups in the taxonomy system overlap?

Answer 8

No

Question 9

How are groups arranged in taxonomy?

Answer 9

In a hierarchy with the largest groups at the top and the smallest groups at the bottom.

Question 10

What is important to note about where organisms are found in the hierarchy in taxonomy?

Answer 10

Each organism can only belong to 1 group at each level in the hierarchy - there’s no overlap.

Question 11

What are the 3 domains?

Answer 11

Eukarya, Bacteria and Archaea.

Question 12

What is the definition of a species?

Answer 12

A group of similar organisms able to reproduce to give fertile offspring.

Question 13

Why do scientists constantly update classification systems?

Answer 13

Because of discoveries about new species and new evidence about known organisms (e.g. DNA sequence data).

Question 14

What naming system is used in classification?

Answer 14

The binomial naming system.

Question 15

How many parts of a name are there is classification?

Answer 15

2

Question 16

What are the 2 parts of the names used in classification?

Answer 16

The first part is the genus name and the second part is the species name.

Question 17

What are the rules for writing names using the binomial naming system?

Answer 17

The first part is the genus name and it has a capital letter.

The second part is the species name and begins with a lowercase letter.

Names are always written in italics (or they’re underlined if they’re handwritten).

Question 18

What does the binomial system help to avoid?

Answer 18

The confusion of using common names as there are lots of common names used for different things.

Question 19

What is courtship behaviour used for?

Answer 19

To help classify species.

Question 20

What is courtship behaviour?

Answer 20

Behaviour that helps attract a mate.

Question 21

What is courtship behaviour essential for?

Answer 21

Survival of a species.

Question 22

What is a taxon?

Answer 22

A group used to classify organisms.

Question 23

What does courtship behaviour allow individuals to do?

Answer 23

Recognise members of their own species,
Identify a mate that is capable of breeding.
Form a pair bond.
Synchronise mating.
Become able to breed.

Question 24

How does courtship help to prevent interbreeding?

Answer 24

Only members of the same species will do and respond to courtship behaviour allowing members of the same species to recognise each other.

Question 25

What is courtship behaviour like with increasing closeness of relation?

Answer 25

The more closely related species are, the more similar their courtship behaviour.

Question 26

What are some examples of courtship behaviour?

Answer 26

Fireflies give off pulses of light in a pattern specific to each species.

Crickets make sounds similar to Morse code, the code being different for different species.

Male peacocks show off their colourful tails - this tail pattern is only found in peacocks.

Male butterflies use chemicals to attract females - only those of the correct species respond.

Question 27

How is courtship behaviour used in classification?

Answer 27

The courtship behaviour is specific to the species.