4.5 Species and taxonomy

Question 1

Define species:

Answer 1

• If two organisms belong to the same species they are able to produce fertile offspring
• Offspring from 2 different species mating may be infertile because they will have an odd number of chromosomes so can’t perform meiosis to produce (haploid) sex cells (gametes)

Question 2

What is the role of courtship in species recognition?

Answer 2

• Allows recognition of members of the same species because courtship behaviour is species specific (production of fertile offspring)
• Indication of sexual maturity
• Recognition/attraction of opposite sex
• Stimulate release of gametes
• Establishes a pair bond to raise young
• Synchronise mating → maximum probability that sperm will fertilise ovum

Question 3

What is the phylogenetic classification system?

Answer 3

Arranges species into groups based on their evolutionary origins (common ancestors) and relationships

Question 4

What is a hierarchy?

Answer 4

• Smaller groups placed within larger groups
• No overlap between each group
• Each group = taxon

Question 5

What is a hierarchy?

Answer 5

• Smaller groups placed within larger groups
• No overlap between each group
• Each group = taxon

Question 6

What does one hierarchy comprises of?

Answer 6

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 7

What is the binomial naming system and name an advantage?

Answer 7

Genus e.g. homo + Species e.g. sapien - = Homo sapien
- Advantage – universal; no confusion as many organisms have more than one common name

Question 8

What is genome sequencing?

Answer 8

Compare the order of base sequence of whole genome of different species

• Higher % match = more closely related e.g. humans and chimps = 96%