species and taxonomy

Question 1

How can it be tested if two animals are of the same species?

Answer 1

If two organisms belong to the same species they are able to produce fertile offspring

Question 2

Give 3 ways in which members of the same species are similar

Answer 2

• Physically Similar
• Biochemically Similar
• Behaviourally Similar

Question 3

Why are courtship rituals important?

Answer 3

Females look for the most impressive display of genes in a mate

Question 4

What do genetically programmed courtship behaviours allow animals to do? [4]

Answer 4

• Identify a member of the same species
• Attract a mate of the opposite sex
• Identify a mate of sexual maturity, capable of breeding
• Form a pair bond to raise offspring (not always)

Question 5

What is selective breeding? [2]

Answer 5

• done by humans
• the breeding of desirable characteristics together to exaggerate them

Question 6

What is Allopatric speciation? [4]

Answer 6

• geographic and reproductive isolation
• different selection pressures in different environments
• particular allele/behaviour favoured
• results in speciation
• if the environment the same on both sides of barrier species won’t differentiate

Question 7

Sympatric speciation

Answer 7

• Occurs in same habitat
• behavioural change between two populations
• become reproductively isolated
• Different alleles passed on / selected for
• Disruptive natural selection occurs
• Eventually two populations cannot reproduce to produce fertile offspring

Question 8

Give 3 examples of Pre-zygotic barriers

Answer 8

• behavioral isolation > e.g. different bird song
• temporal isolation > e.g. different breeding season
• habitat isolation > e.g. preferring different environments (terrestrial / water)

Question 9

Give 3 example of Post-zygotic barriers

Answer 9

• offspring unable to reproduce
• offspring weak / dies
• offspring can’t develop

Question 10

What is a phylogenetic classification system? [3]

Answer 10

• Arranges species into groups based on their evolutionary origins (common ancestors) and relationships
• Smaller groups placed within larger groups
• No overlap between groups
• Each group = taxon

Question 11

Hierarchy + mnemonic [8]

Answer 11

Domain (drunken)
Kingdom (kangaroos)
Phylum (punch)
Class (children)
Order (on)
Family (family)
Genus (game)
Species (shows)

Question 12

What is each species identified by? + example

Answer 12

Each species is universally identified by a binomial consisting of the name of its genus and species
Genus e.g. homo + Species e.g. sapien = Homo sapien
(1st letter capitalised only)