Module 4.3 - Classification And Evolution

Question 1

Why do we classify organisms?

Answer 1

For convenience for more manageable study of organisms
To make it easier to identify organisms
To help see relationships between organisms

Question 2

List the 8 taxonomic groups used for classification

Answer 2

Domains
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 3

Why do classification systems change over time?

Answer 3

Scientific knowledge changes as new discoveries are made
Technological developments lead to new discoveries (e.g. microscopes, new DNA technology)
Differences of opinion amongst biologists/scientists

Question 4

Why is the binomial name given in Latin?

Answer 4

It acts as a universal language so everyone in the world can use and understand it

Question 5

Limitations of common names

Answer 5

Same species can have a different common name in another place
Different common names in different languages
Same common name could be used for a different species in another place

Question 6

Define classification

Answer 6

Process of sorting living things into groups of similar organisms
Reflects how closely related they are and evolutionary relationships

Question 7

Define taxonomy

Answer 7

Study of principles behind classification

Study of the differences between species (physical and genetic)

Question 8

Define phylogeny

Answer 8

Study of the evolutionary relationships between organisms

Study of how closely related they are

Question 9

Name the 5 kingdoms

Answer 9

Animals
Plants
Fungi
Protoctista
Prokaryotes

Question 10

Characteristics of animal kingdom

Answer 10

Eukaryotes
Multicellular
Heterotrophic feeders
No cell walls
Fertilised eggs develop into blastula
Move freely

Question 11

Characteristics of plant kingdom

Answer 11

Eukaryotes
Multicellular
Autotrophic nutrition
Cellulose cell walls
Fertilised eggs develop into multicellular embryos
Contain chlorophyll

Question 12

Characteristics of fungus kingdom

Answer 12

Eukaryotes
Most multicellular (yeast unicellular)
Saprophytic feeders
Chitin cell walls
Reproduce with spores
Multinucleate cytoplasm
Have a mycelium made up of hyphae

Question 13

Characteristics of Protoctist kingdom

Answer 13

Eukaryotes
Mostly unicellular
Autotrophic or heterotrophic feeders
Variety of different forms
Do not fit into any other kingdom, display features of multiple kingdoms

Question 14

Character is of prokaryote kingdom

Answer 14

Prokaryotes (no nucleus, loop of naked DNA, no histones)
No membrane bound organelles
Ribosomes smaller than 70S
Smaller than eukaryotes
May be free living or parasitic

Question 15

Define heterotrophic feeders

Answer 15

Eat and digest other organisms

Question 16

Define autotrophic feeders

Answer 16

Use photosynthesis to make their own food

Question 17

Define saprotrophic feeders

Answer 17

Digest other organisms outside the body using enzymes

Question 18

Explain why the appearance and anatomy of Fungi made their classification difficult for early taxonomists

Answer 18

Don’t move freely (like plants)
Hyphae resemble roots
Digest food rather than photosynthesising (like animals)

Question 19

What were early classification systems based on?

Answer 19

Appearance

Anatomy

Question 20

Limitations of early classification systems

Answer 20

Easy to make mistakes

Easy to place relatively distance species in the same groups

Question 21

How is biochemistry used in modern classification?

Answer 21

Cytochrome C is a protein used in respiration so almost every living organism has it
The primary structure of cytochrome C varies from species to species
If primary structure is the same - closely related
If primary structure is different - less related

Question 22

How are genetics used in modern classification?

Answer 22

The genetic code (order of bases in DNA) is universal so a sequence in one gene in one organism codes for the same protein in any organism
Compare DNA of different species
More similar genetic code means more closely related and visa versa

Question 23

Name the 3 domains

Answer 23

Eubacteria
Archaebacteria
Eukaryotae

Question 24

How was the 3 domain system developed?

Answer 24

Studying RNA

Question 25

Most closely related of the 3 domain system

Answer 25

Archaebacteria and eukaryotae

Question 26

Features of eubacteria

Answer 26

Different cell membrane structures
Different flagella structures
Naked DNA
Different mechanisms for DNA replication and RNA synthesis

Question 27

Shared features of archaebacteria and eukaryotae

Answer 27

Similar mechanisms for DNA replication and RNA synthesis

Proteins bound to DNA (another way organisms can now be classified into their taxonomic groups)