SUMMARY QUESTIONS

Question 1

state the 1 thing that all members of a species share

Answer 1

They are capable of breeding to produce offspring which are themselves fertile

Question 2

list the 3 features of a phylogenetic system of classification

Answer 2

• its based on evolutionary relationships between organisms and their ancestors
• it classifies species into groups using shared characteristics derived from their ancestors
• its arranged in a hierarchy in which groups are contained within larger composite groups with no overlap

Question 3

explain why species recognition is important in courtship

Answer 3

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

Question 4

suggest a way in which the courtship behaviour of 1 species might be used to determine which if the 2 other species is most closely related to it

Answer 4

• the courtship display that most closely resembles that of the first species is likely to be the closest relative

Question 5

Rana temporaria is the frog commonly found in Britain (this table is incomplete) and it shows part of its classification. State the most appropriate name for each of the blanks represented by the numbers 1-7

Answer 5

1) Phylum
2) class
3) order
4) family
5) Rana
6) species
7) temporaria

Question 6

State which group is the closest relative of the snakes

Answer 6

Lizards

Question 7

State whether dinosaurs are more closely related to crocodiles or birds

Answer 7

Birds

Question 8

Suggest what C represents

Answer 8

Common ancestors of lizards and snakes

Question 9

Suggest a reason why dinosaurs are not shown along the time line like all the other groups

Answer 9

Dinosaurs are extinct but all the other groups are still living so they are shown extending further along the time line - as far as ‘present’

Question 10

Explain what is meant by species diversity

Answer 10

The number of species and the proportion of each species within a given area/community

Question 11

Explain why its more useful to calculate a species diversity index than just to record the number of species present

Answer 11

• It measures both the number of species and the number of individuals
• It therefore takes account species that are only present in small numbers

Question 12

Explain how agriculture has reduced species diversity

Answer 12

• the few species possessing desirable qualities are selected for and bred
• other species are excluded, by culling or the use of pesticides
• Many individuals of a few species = low species diversity

Question 13

Explain why there’s a reduction in species diversity when a forest is replaced by grassland for grazing sheep or cattle

Answer 13

• Because forests, have many habitats with many different species, i.e. high species diversity
• grasslands have fewer habitats, fewer species and therefore lower species diversity

Question 14

Suggest why the draining of ponds on agricultural land might have a greater effect on biodiversity than removing a hedgerows

Answer 14

• ponds provide a habitat for a wide range of aquatic species that are unlikely to find alternative habitats as aquatic habitats are few
• ponds may be a source of food and water for terrestrial species which may also not survive without them
• Hedgerow species are likely to have a larger range of alternative habitats as most of the area around will be terrestrial with other sources of food and shelter and so fewer species are likely to be lost

Question 15

Explain what causes the DNA sequences of genes to change over a period of time

Answer 15

Mutations

Question 16

Using the information in the diagram, state (with reasons) which 2 species are most closely related

Answer 16

Species 2 and 3 because their amino acid sequences are identical