Species & Taxonomy

Question 1

Define species.

Answer 1

A group of similar organisms able to reproduce and produce fertile offspring.

Question 2

How do we name organisms?

Answer 2

Genus species
(usually in italics or underlined with the genus being capitalised and the species not)
Homo sapien

Question 3

Define hierarchical system.

Answer 3

Smaller groups are contained with larger groups. There is NO OVERLAP - organisms can be found in only one taxa in each level.

Question 4

What is the order of the classification system?

Answer 4

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 5

What’s a pneumonic to remember the order of the classification system?

Answer 5

Don’t
Kill
Professor
Crumpets
Over
Fairly
Graded
Scores

Question 6

What is phylogenetics?

Answer 6

The study of patterns of evolutionary history.
All organisms evolved from a shared common ancestor.
Organisms which share a more recent common ancestor are more closely related

Question 7

What does a phylogenetic tree show us?

Answer 7

Common ancestors

Question 8

What is courtship behaviour?

Answer 8

Behaviour that results in mating by attracting mates and eventual reproduction.

Question 9

How does courtship behaviour help us classify species?

Answer 9

The sequence of events that make up courtship behaviour is specific to each species. A female will not respond to or mate with a male that displays an incorrect courtship dance.

Question 10

What are the 3 ways in which we can use DNA and proteins to classify organisms?

Answer 10

Species that are more closely related are likely to have fewer differences in the sequence of their DNA bases. Therefore, we are more likely to classify species into the same group if they have the same genetic variation in their
genome.

Question 11

Give three ways in which courtship behaviours increases the probability of successful mating. (3)

Answer 11

Recognise attract same species
Stimulates production/ release of gametes;
Attraction of opposite sex
Indication of fertility
Formation of a pair bond / bond between two organisms

Question 12

The forest was cleared to make more space for agriculture.
After the forest was cleared, the species diversity of insects in the area decreased. Explain why (3)

Answer 12

1. Fewer plant species
2. Fewer habitats/niches
3. Decrease in variety of food