As Ocr Biology - More On Biodiversity

Front 1

What may happen to a species with low genetic diversity?

Back 1

• They might not be able to adapt to a change in the environment and be wiped out by a single event (e.g. disease).

Front 2

Give an example of a factor that may lower genetic diversity in a population.

Back 2

• Isolated populations
• Examples are those that are bred in captivity (e.g. zoos, and pedigree and rare breeds)

Front 3

What is a pedigree animal?

Back 3

An animal bred purely from animals from the same breed.

Front 4

What is a rare breed?

Back 4

A breed of farm animal that's not used in large-scale farming.

Front 5

Give an example of how the genetic diversity of a population could be increased

Back 5

Breeding programmes.

Front 6

Genetic .......... is used to measure genetic diversity

Back 6

polymorphism

Front 7

What is a locus on a chromosome?

Back 7

The point where alleles of the same gene are found at the same point.

Front 8

What does polymorphism describe?

Back 8

A locus that has two or more alleles.

Front 9

Working out the polymorphic gene loci in an organism gives you a measure of genetic diversity. State the formula used to calculate the proportion of polymorphic gene loci.

Back 9

Front 10

State three factors affecting global biodiversity.

Back 10

• Human population growth
• Increased use of monoculture in agriculture
• Climate change

Front 11

State four factors that affect biodiversity due to human population growth

Back 11

• Habitat loss
• Over-exploitation
• Urbanisation
• Pollution

Front 12

How does habitat loss affect global biodiversity?

Back 12

• Human development is destroying habitats, e.g. there is deforestation in the Amazon to make way for grazing and agriculture.
  

Front 13

How does over-exploitation affect global biodiversity?

Back 13

• Over-exploitation - a greater demand for resources means a lot of resources are being used up faster than they are replenished.
• This decreases genetic diversity within populations, as well as species diversity (as a result of extinction).
• An example of this is industrial fishing, which can deplete populations of certain fishes and even end up causing extinction.
  

Front 14

How does urbanisation affect global biodiversity?

Back 14

• Sprawling cities and major road developments can isolate species, meaning populations are unable to interbreed and genetic diversity is decreased.

Front 15

How does pollution affect global biodiversity?

Back 15

• High amounts of pollutants can kill species and destroy habitats.
• An example is a large amount of fertiliser flowing into a river, killing the fish species in the river, reducing biodiversity.

Front 16

What is monoculture?

Back 16

The growing of a single variety of a single crop.

Front 17

How does monoculture in agriculture decrease global biodiversity?

Back 17

• Habitats are lost as land is cleared to make way for large fields.
• Local and naturally occuring plants and animals are seen as weeds and pests, and destroyed with pesticides and herbicides, reducing species diversity.
• Heritage (traditional) varieties of crops are lost because they don't make enough money and are not planted any more.

Front 18

What is climate change?

Back 18

The variation of the earth's climate (e.g. changes in the temperature and rainfall patterns).

Front 19

Climate change occurs naturally, but the scientific consensus is that the climate change we are experiencing is due to humans. What is one of the causes of climate change due to humans?

Back 19

The increased emissions of greenhouse gases.

Front 20

Greenhouse gases cause .......... warming (increasing the global average ..........), which causes other types of climate change, e.g. changing ........ patterns.

Back 20

1. global

2. temperature

3. rainfall

Front 21

Climate change will affect .......... areas of the world in different ways - some places will get warmer, some ........, some wetter and others ........... .

Back 21

1. different

2. colder

3. drier

Front 22

Most species require a particular .......... .

Back 22

climate

Front 23

What can a change in climate do to a habitat? What may this result in? Give an example of a species this has affected. What would happen if a species cannot react fast enough to this change?

Back 23

• An area that was once habitable may become inhabitable, but the same thing may occur the other way, and inhabitable may become habitable.
  
• This may increase or decrease the range (the area in which they live) of some species. This can increase or decrease biodiversity,
• The southern range of the Sooty Copper butterfly has moved 60 miles north in recent decades.
• If a species can not react fast enough to this change (e.g. migrate), or if the change is too fast, it could result in the extinction of a species.