4.2.2 - Classification & Evolution

Question 1

Definition of a species

Answer 1

Two individuals that can breed together to produce fertile offspring

Question 2

Taxonomic hierarchy

Answer 2

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 3

Binomial Naming system

Answer 3

Must be underlined

Genus -> Species

Genus needs to be capitalised

Question 4

Sapro/hetero/auto- trophs

Answer 4

Saprotrophic - Absorbs dead/decaying organic matter
Heterotrophic - Obtain nourishment through digesting plant/animal matter
Autotrophic - Capable of producing nutrient from inorganic matter `

Question 5

5 Kingdoms: Prokaryote

Answer 5

• No membrane bound organelles
• Cell wall: Peptidoglyan
• Unicellular
• External digestion; Heterotrophic (by segregating enzymes onto food and absorbing the products), Autotrophic & Saprotrophic

Question 6

5 Kingdoms: Protocista

Answer 6

• Membrane bound organelles
• Cell wall: Present, varying compositions
• Heterotrophic & Autotrophic
• Unicellular or multicellular

Question 7

5 Kingdoms: Fungi

Answer 7

• Membrane bound organelles
• Cell wall: Chitin
• External digestion; Heterotrophic (secrete enzymes) & Saprotrophic
• Reproduce by releasing spores from hyphae
• Multi-nucleate
• Multicellular or unicellular

Question 8

5 Kingdoms: Plantae

Answer 8

• Membrane bound organelles
• Cell wall: Cellulose
• Autotrophic
• Multicellular

Question 9

5 Kingdoms: Animalia

Answer 9

• Membrane bound organelles
• No cell wall
• Heterotrophic
• Multicellular

Question 10

How to tell if species are different

Answer 10

Observable feature - Physical features are different, can be grouped in a phylogenetic tree

DNA - Similarities between base sequence of DNA, can determine how closely a species is related

Biochemistry (Cytochrome C) - Sequence of amino acids can determine how close species are to each other

Behaviour - Similar behaviours eg feeding habits

Question 11

Exam Question:

‘Suggest what criteria a taxonomist might take into account when classifying a new species’ (3)

Answer 11

1. Morphology/ Anatomy/ (observable/physical) features/ appearance
2. Biochemistry/ cytochrome C
3. Genes/ DNA/ genetics/ RNA
4. Behaviour/ physiology/ embryology
5. Shared evolutionary past/ Phylogeny

Question 12

3 Domains: Bacteria (Composition)

Answer 12

Cell type: Prokaryotic
Cell wall: Peptidoglycan
RNA Polymerase: Less complex than eukaryotes
First amino acid: Formylmethionine
DNA: Mostly circular chromosomes & plasmids
Histone:
Organelles:
Ribosomes: