Unit 5.3: Classification of Biodiversity

Question 1

Explain binomial nomenclature.

Answer 1

It is the use of two names to refer to each type of organism. The structure of binomial nomenclature is Genus name and then species name (italicized when typed). It is an international system so that all scientists use the same names for species.

Question 2

What are the three domains?

Answer 2

Bacteria, Archaea (ancient bacteria), and eukaryota (eukaryotic organisms)

Question 3

List all parts of principal taxa for eukaryotes.

Answer 3

Kingdom
Phylum
Class
Order
Family
Genus
Species.

If two organisms share the same order, they will also share the same class, phylum, kingdom, and domain.

Question 4

Explain natural classification.

Answer 4

It is a mode of classification in which all members of a genus or higher taxon should have a common ancestor.

Question 5

Explain unnatural selection.

Answer 5

It is the result of convergent evolution, in which organisms have similar features but different ancestors. For instance, the classification of birds, bats, and insects together because they all had wings. Or plants and fungi, because they both have cell walls, even though the walls of fungi are chiton and the walls of plants are cellulose.

Question 6

List the advantages of natural classification.

Answer 6

• Identifying species is easier, because if the species of an organism is not obvious, one can first determine its kingdom, etc.
• Members of a species tend to have very similar characteristics because they all evolved from a common ancestor.

Question 7

What is a dichotomous key?

Answer 7

A dichotomous key consists of pairs of choices, each of which lead to another pair of choices or gives the identification of an organism.