Evolution of classification systems

Question 1

why might observable features, in old classification systems might be a problem

Answer 1

this is because it does not allow us to see how related organisms are
It only allows us to see their physical features

Question 2

what four new evidences do we use in new classification systems?

Answer 2

1) molecular evidence
2) Embryological evidence- similarities in the early stages of an organism’s development.
3) Anatomical evidence - similarities in the structure and function of different body parts
4) Behavioural evidence- similarities in the behaviour and social organisation of organisms

Question 3

molecular evidence in new classification systems

Answer 3

• similarities in proteins and DNA
• you can compare how DNA is stored and the sequence of DNA bases
• compare sequence of amino acids

Question 4

how are new organisms discovered

Answer 4

1) new Dna techniques
2) better microscopes
3) scientists can share their discoveries at meetings

Question 5

The three domain system

Answer 5

EUKARYA - ( originated from 4/5 of the kingdoms)
ARCHAEA- ( originated from the prokaryotae kingdom
BACTERIA - ( originated from the prokaryotae kingdom)

Question 6

why was the prokaryotae kingdom reclassified into 2 domains ( 2 bits of evidence)

Answer 6

large differences between archaea and bacteria

Molecular evidence: The RNA polymerase is different in bacteria and archaea
Archaea have similar histones to eukarya

histones are proteins that bind to DNA

cell membrane evidence: Bonds of lipids in the cell membrane of the archaea and the bacteria are different. The development and composition of flagellae are also different

Question 7

development of the three domain system is a sign of what….

Answer 7

It is an example of how scientific evidence is always changing and improving