Topic 3: Classification

Question 1

Define Classification…

Answer 1

the process of naming and organising organisms into groups based on characteristics

Question 2

Name the 8 classification groups in order…

Answer 2

DOMAIN
KINGDOM
CLASS
ORDER
FAMILY
GENUS
SPECIES

Question 3

Define Species…

Answer 3

organisms that can interbreed to produce fertile offspring

Question 4

Give a limitation to the definition of species…

Answer 4

does not take into account species who reproduce through asexual reproduction

Question 5

Why can it be difficult to assign organisms to just one species

Answer 5

• species often change morphologically and genetically over time
• how similar do organisms have to be to each other to be classed in the same species
• hybrids

Question 6

How can we analyse evolutionary relationships genetically?

Answer 6

1. gel electrophoresis
2. DNA replication
   3.bioinformatics

Question 7

How does gel electrophoresis work?

Answer 7

Fluorescent DNA fragments are placed at one end of an agar plate
Electric current is applied
Fragments move to positive charged side of the plate
Smaller the fragment the further it travels

Question 8

How does DNA sequencing work?

Answer 8

DNA is broken into fragments
Terminated at different lengths by fluorescent nucleotides
Then duplicated by using PCR
Undergoes GEL ELECTROPHORESIS
Read the DNA based on distance each fragment has travelled

Question 9

What is bioinformatics?

Answer 9

Technology used to analyse large amounts of biological data
Can compare entire genomes and look for where mutation have caused divergence in the phylogenetic tree

Question 10

Why has the five-kingdom model come under scrutiny?

Answer 10

Relies heavily on physical observations

Question 11

Why does natural selection occur?

Answer 11

Predation
Disease
Competition

Question 12

Explain how natural selection results in development of new characteristics

Answer 12

*Random mutations result in new alleles
*Some alleles give the possessor an advantage over the rest of the species, making them more likely to survive and reproduce
*Their offspring receive the new allele, and frequency continues to increase over generations

Question 13

What are three types of adaptation

Answer 13

*Anatomical (changes in body structure), e.g. oily fur
*Physiological (changes to bodily processes), e.g. venom production
*Behavioural (changes to actions), e.g. hibernation

Question 14

Define a niche.

Answer 14

The position of an organism within their ecosystem

Question 15

Define speciation.

Answer 15

Where a population is split and reproductively isolated, there are different selective pressures on the two groups.
* if the groups genetic makeups change to the extent where they can no longer interbreed, they become a separate species

Question 16

What is meant by allopatric speciation?

Answer 16

Speciation as a result from a physical barrier, e.g. river, mountain range

Question 17

What is meant by sympatric speciation?

Answer 17

Speciation resulting from a non-physical barrier, e.g. a mutation no longer allows two organisms to produce fertile offspring

Question 18

What is biodiversity?

Answer 18

The variety of different species in an ecosystem

Question 19

What is an allele?

Answer 19

Different forms of a particular gene, found at the same locus on a chromosome

Question 20

Give a reason why we should maintain biodiversity.

Answer 20

• More stable, resilient populations
  *Ecotourism opportunities
• Provide sources of medicine
• Increase the gene pool

Question 21

What is adaptive radiation?

Answer 21

When on species evolves rapidly to form a number of different species, which all fill different ecological niches