4. Genetic Information Variation and Relationships - Species and Taxonomy

Question 1

What is classification?

Answer 1

The organisation of living organisms into groups.

Question 2

What is the one main feature that members of a single species have in common?

Answer 2

The are capable of breeding to produce living, fertile offspring.

Question 3

What system is used to identify organisms?

Answer 3

The binomial system.

Question 4

What are the features of the binomial system?

Answer 4

• It’s a universal system based upon Latin or Greek names
• The first name, called the generic name, denotes the genus to which the organism belongs
• The second name, called the specific name, denotes the species to which the organism belongs

Question 5

What are the rules that are applied to the use of the binomial system in scientific writing?

Answer 5

• Names are printed in italics or, if handwritten, they are underlined to indicate they are scientific names
• The first letter of generic name is in upper case, but the specific name is in lower case
• If the specific name is not known, it can be written as ‘sp’

Question 6

What is courtship behavior?

Answer 6

Members of the same species have similar, or have the same gees and therefore resemble one another physically and biochemically. It helps them to distinguish members of their own species from those of other species.

Question 7

Give 5 ways in which courtship behavior ensures successful mating producing offspring that have the maximum chance of survival:

Answer 7

• Recognise members of their own species - to ensure mating only takes place between members of the same species because only members of the same species can produce fertile offspring
• Identify a mate that is capable of breeding - because both partners need to be sexually mature, fertile and receptive to mating
• Form a pair bond - that will lead to successful mating and raising of offspring
• Synchronise mating - so that it takes place when there is the maximum probability of the sperm and egg meeting
• Become able to breed - by bringing a member of the opposite sex into a physiological state that allows breeding to occur

Question 8

What is taxonomy?

Answer 8

The theory and practice of biological classification.

Question 9

What is classification?

Answer 9

The grouping of organisms.

Question 10

What are the two main forms of biological classification?

Answer 10

• Artificial classification
• Phylogenetic classification

Question 11

What is artificial classification?

Answer 11

It divides organisms according to differences that are useful at the time. Such features may include colour, size, number of legs etc. These are described as analogous characteristics where they have the same function but do not have the same evolutionary origins.

For example, the wings of butterflies and birds are both used for flight but they originated in different ways.

Question 12

What is phylogenetic classification?

Answer 12

• Is based upon the evolutionary relationships between organisms and their ancestors
• Classifies species into groups using shared features derived form their ancestors
• Arranges the group into a hierarchy, in which the groups are contained within larger composite groups with no overlap

Question 13

What are homologous characteristics?

Answer 13

They have similar evolutionary origins regardless of their functions in the adult of a species.

Question 14

What is the order of taxonomic ranks?

Answer 14

Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Question 15

What are the 3 recognised domains?

Answer 15

Bacteria, Archaea (a group of prokaryotes) and Eukarya.