4.5 Species and taxonomy

Question 1

What is a species?

Answer 1

A group of organisms that can interbreed to produce fertile offspring

Question 2

What are the advantages of courtship behaviour?

Answer 2

Individuals can recognise sexually mature members of their own species of the opposite sex, synchronise mating, form a pair bond and successfully breed

Question 3

Why does courtship behaviour enable individuals to recognise members of their own species?

Answer 3

to ensure that mating only takes place between members of the same species because only members of the same species can produce fertile offspring

Question 4

Why does courtship behaviour enable individuals to identify a mate that is capable of breeding?

Answer 4

because both partners need to be sexually mature, fertile and receptive to mating

Question 5

Why does courtship behaviour enable individuals to form a pair bond?

Answer 5

will lead to successful mating and raising of offspring

Question 6

Why does courtship behaviour enable individuals to synchronise mating?

Answer 6

so that it takes place when there is the maximum probability of the sperm and egg meeting

Question 7

Why does courtship behaviour enable individuals to become able to breed?

Answer 7

by bringing a member of the opposite sex into a physiological state that allows breeding to occur

Question 8

What is classification?

Answer 8

the process of arranging organisms into groups

Question 9

What are the 2 main forms of biological classification?

Answer 9

• artificial classification
• phylogenetic classification

Question 10

What is artificial classification?

Answer 10

• divides organisms according to differences that are useful at the time.
• e.g. colour, size, number of legs, leaf shape

Question 11

What is phylogenetic classification?

Answer 11

the process of arranging organisms into groups based on their evolutionary origins and relationships

Question 12

What is a taxonomy?

Answer 12

the study of groups and their positions in a hierarchical order

Question 13

Name the 8 groups of organism can be classified into, from largest to smallest.

Answer 13

domain -> kingdom -> phylum -> class -> order -> family -> genus -> species

Question 14

What system is used to give species a universal name?

Answer 14

Binomial naming system

Question 15

What are the 2 components to a binomial name?

Answer 15

Generic name = the genus the organism belongs to. 2 closely related species will share the sane genus
Specific name = the species the organism belongs to

Question 16

How are binomial names handwritten?

Answer 16

the first letter of the generic name should be capitalised, with the rest in lowercase. The whole name should be underlined

Question 17

How can we clarify evolutionary relationships between organisms?

Answer 17

Analyse their molecular differences. Advances in immunology/genome sequencing provide clear pictures of how related two organisms are

Question 18

What is hierarchical classification?

Answer 18

• groups within groups
• no overlap between groups

Question 19

What are the 3 domains?

Answer 19

• bacteria
• archaea
• eukarya

Question 20

What are features of bacteria?

Answer 20

• absence of membrane bound organelles such as nuclei or mitochondria
• unicellular
• ribosomes are smaller 70S than in eukaryotes
• cell walls are present and made of murein
• single loop of naked DNA made up of nucleic acids but no histones

Question 21

How do archaea differ from bacteria?

Answer 21

• their genes and protein synthesis are more similar to eukaryotes
• their membranes contain fatty acid chains attached to glycerol by ether linkage
• there is no murein in their cell walls
• they have a more complex form of RNA polymerase

Question 22

What are the features of eukarya?

Answer 22

• their cells possess membrane-bound organelles such as mitochondria and chloroplasts
• they have membranes containing fatty acid chains attached to glycerol by ester linkages
• not all possess cells with a cell wall, but where they do it contains no murein
• ribosomes are larger 80S than in bacteria and archaea

Question 23

What is the eukarya domain divided into?

Answer 23

4 kingdoms:
Protoctista, Fungi, Plantae and Animalia

Question 24

What is phylogeny?

Answer 24

evolutionary relationship between organisms, reflects the evolutionary branch that led up to it