Biodiversity

Question 1

Define biodiversity

Answer 1

The number and variety of genes, species and habitats in a particular area

Question 2

Define Community

Answer 2

All the living organisms present in an ecosystem at a given time

Question 3

Define population

Answer 3

Group of individuals of the same species which live in a particular area at a given time

Question 4

Define habitat

Answer 4

Where a population lives and which is characterised by physical conditions and the types of other organisms present

Question 5

Define ecosystem

Answer 5

All living and non living components of a particular area

Question 6

Define niche

Answer 6

all the conditions and resources required for an organism to survive and reproduce (its ‘role’ in the ecosystem)

Describes how an organism fits into its environment. It describes what a species is like, where it occurs, how it behaves, it’s interactions with other species and how it responds to its environment

Question 7

Define species diversity

Answer 7

The number of different species and the number of individuals of each species with any one community

Question 8

Define genetic diversity

Answer 8

Number of different alleles of each gene

The variety of genes possessed by the individuals that make up a population of a species

Question 9

Define ecosystem diversity

Answer 9

Range of different habitats from a small local habitat to the whole of the earth

Question 10

How do you assess genetic diversity

Answer 10

Compare base sequences of DNA, base sequence of mRNA and Amino acid sequences in proteins

Question 11

How do you assess ecosystem diversity

Answer 11

Assess the range of different habitats and investigate these by recording measures of aerobic characteristics.

Question 12

Define species richness

Answer 12

(A measure of species diversity)

The number of different species in a particular area at a given time

Question 13

How does biodiversity reflect how well an ecosystem is likely to function

Answer 13

The higher the species diversity index the more stable and ecosystem:
They’re less affected by change because there’s a higher chance of at least one species surviving and therefore can maintain community

Question 14

Is species diversity high or low in extreme environments?why?

Answer 14

Low. Communities are dominated by climatic factors rather than by organisms within the community

Question 15

natural habitat Factors affecting biodiversity

Answer 15

Climate change
Interactions of invasive and non invasive species
Natural disasters

Question 16

Man made habitat factors affecting biodiversity

Answer 16

Deforestation
Pollution
Climate change

Question 17

Weakness of Simpson species diversity index

Answer 17

Makes no allowance for difference in sizes of individuals

Question 18

Strength of Simpson species diversity index

Answer 18

It is quantitive- provides a number that makes it easier to compare the variety in different habitats
Takes into account species evenness as well as species richness

Question 19

Impact of agriculture on biodiversity (5)

Answer 19

Low diversity index
Number of species, genetic variety of alleles decreases as farmers select species that have desired features
Economics- prioritise land available for the species with desired features- other species have to compete for spaces and resources
Pesticides
All leads to decrease in species diversity

Question 20

Practices that have directly removed habitats and reduced species diversity

Answer 20

Removal of hedgerows
Creating monocultures- (monocultures are where only one crop is grown)
Filling in ponds/draining marsh
Overgrazing land- prevents regeneration of woodland
Use of pesticides and inorganic fertilisers
Absence of crop rotation and lack of intercropping

Question 21

What is intercropping

Answer 21

Planting 2 diff crops in the same field

Question 22

Cultural methods of pest control

Answer 22

Weeding
Crop rotation
Growing crops at a particular time in the life cycle of pests
Removing remains of crops and badly damaged plants which might harbour pests
Creating physical barrier
Intercropping
Covering soil with organic material-prevents light reaching weeds

Question 23

How does crop rotation increase species diversity

Answer 23

Discourages the build up of several potentially damaging pest species- only effective when a pest can’t attack successive crops

Question 24

Define pest

Answer 24

Undesirable organism

Question 25

Chemical control

Answer 25

Pesticides: fungicides, herbicides, insecticides

Broad spectrum pesticides

Question 26

Types of pesticides

Answer 26

Contract pesticides: kills pest without being eaten

Systemic pesticides: taken into a plant and translocated within so enters pest when eating the plant

Question 27

How could pesticides lose effectiveness

Answer 27

Pests develop resistance

Question 28

Biological control

Answer 28

A predator (eg ladybird), parasite or disease causing organism is used 
Aim is to maintain low population of pests, not eliminate them

Question 29

Benefits of hedges

Answer 29

Increases diversity of plant, creating a greater variety of habitats and nesting so increase in diversity of animals

Increase species diversity
Acts as corridors for species to move along
Produce food for animals that live in hedgerows and those who don’t

Question 30

Why were hedgerows removed

Answer 30

Increase land for machinery which is large
Increase farm sizes
Increase land for crops