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:

Answer 2

Domain 
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 3

Variation shown by organisms in each taxonomical group

Answer 3

Variation decreases going down taxonomic groups.

Down from Domain to Species

Question 4

How closely are species related in taxonomic groups?

Answer 4

Relation increases down the taxonomic groups

Increases down form domain to species

Question 5

Why do classification systems change over time?

Answer 5

• scientific knowledge changes as new discoveries are made
• technological developments lead to new discoveries;
• named technological development; e.g. microscopes, new DNA technology
• differences of opinion amongst biologists/scientists

Question 6

In which classification level is the most variation seen?

Answer 6

Domain

Question 7

In which classification level is the least variation seen?

Answer 7

Species

Question 8

State the 8 levels of classification

Answer 8

Domain 
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 9

Why do common names for organisms have limitations in classification?

Answer 9

• Same species have different common names in different places
• Different languages would give different common names
• Same common name could be used for different species in different places

Question 10

What language is the binomial naming system in?

Answer 10

Latin

Question 11

How is the binomial name formed?

Answer 11

First word: Genus - capital letter
Second word: Species - lower case letter
Written in italics or underlined

Question 12

Classification def

Answer 12

Process of sorting lining things into groups of similar organisms.
It reflects how closely related they are and evolutionary relationships

Question 13

Taxonomy def

Answer 13

The study of the principles behind classification

- the study of the differences between species(physical and genetic)

Question 14

Phylogeny def

Answer 14

The study of the evolutionary relationships between organisms
- the study of how closely related they are

Question 15

List the five different kingdoms

Answer 15

• Prokaryotae
• Protoctista
• Fungi
• Plantae
• Animalia

Question 16

Description of prokaryotae kingdom

Answer 16

• have no nucleus
• have a loop of DNA that is not arranged in linear chromosomes
• have named DNA(DNA that is not associated with histone proteins
• Have no membrane-bound organelles
• Have smaller ribosome than in other groups(70S)
• Have cells smaller than those of eukaryotes
• May be free-living or parasitic(some may cause diseases

Question 17

Description of protoctista

Answer 17

• Are eukaryotic
• are mostly single-celled(but many algae are multicellular
• show a wide variety of forms(the only thing protoctists have in common is that they do not qualify to belong to any of the other four kingdoms!)
• show various plant#like or animal-like features
• are mostly free-living
• have autotrophic or heterotrophic nutrition - some photosynthesise, some ingest prey, some feed using extra cellular enzymes(like fungi), and some are parasites

Question 18

Fungi Description

Answer 18

• are eukaryotic
• can exist as singe cells(called yeasts) or have a mycelium that consists of hyphae
• have cell walls made of chitin
• have a cytoplasm that is multinucleate
• are mostly free-living and saprophytic- meaning they can cause a decay of organic matter

Question 19

Plantae description

Answer 19

H

Question 20

Animalia description

Answer 20

H

Question 21

Heterotrophic feeder meaning

Answer 21

Eat and digest other organisms

Question 22

Autotrophic feeder meaning

Answer 22

Use photosynthesis to produce their own food

Question 23

Saprotrophic feeder meaning

Answer 23

Digest other organisms outside the body using extra cellular enzymes

Question 24

Hierarchy def

Answer 24

Groups within groups with no overlap

Question 25

Species def

Answer 25

-A group of organisms similar in appearance, physiology and genetics whose members are able to interbreed to produce fertile offspring

Question 26

5 forms of vertebrates

Answer 26

• Mammals
• Birds
• Fish
• Reptiles
• Amphibians

Question 27

It has been found that 98.4% of chimpanzee DNA is identical to that of a human.
(i) Suggest how the information obtained by DNA analysis can be useful to taxonomists.
(2 Marks)

Answer 27

• Information can be used to decide which species an organism fits into; easier to classify organisms
• compare DNA base sequences between organisms - the more similar the base sequences, the more closely related the two organisms are.

Question 28

State two types of evidence, other than biochemical evidence, that are used by taxonomists when classifying organisms.
(2 Marks)

Answer 28

• Fossil records
• Physiology/anatomy/behavioural characteristics
• embryology