Biology Biodiversity and Classification

Outline the significance of a low value for Simpson’s index of Diversity (2)

• habitat dominated by one species

• ecosystem unstable/ less likely to be able to cope with change

Give 3 advantages of conserving plant species as seeds and not as adult plants (3)

• easy to transport

• larger numbers can be stored easily

• low maintenance costs

• stay viable for long periods

• less susceptible to disease

Explain why it is sometimes necessary to conserve a plant species outside its natural habitat (ex situ)

• natural habitat lost due to climate change or deforestation

• protection from diseases

• protection from competing species

• can maintain the gene pool ex-situ

Outline a sampling method that can be used to measure the biodiversity of plant species in grassland (4)

• random sampling

• place two measuring tapes 90 degrees to each other on edges of the grassland

• quadrats at regular intervals along the length of the transects

• count how many of each plant species present in each quadrat

• use an identification key to identify the plant

• use a standardised method for counting the number of plants

• 10 repeats

• in different seasons/ different times of year

Scientists try to estimate the total number of species on Earth. Suggest three reasons why such estimates are unlikely to be accurate.

some habitats inaccessible/ unexplored

evolution ongoing - new species constantly forming

organisms constantly become extinct

some species difficult to distinguish

Define the term biodiversity

the range of species, habitats and variety of alleles

3 criteria to consider in an environmental impact assessment

size of development

which species/ habitats present in the area

potential damage to organisms

strategies to minimise impact

State the name given to evolution of a new species

speciation

How can zoos contribute to conservation? (3)

captive breeding

education/awareness

donate money to conservation programmes

preservation of a habitat/species does NOT involve

human intervention

Describe evidence that supports the theory of evolution (5)

fossils

• compare extinct organisms with living organisms

biological molecules

• similarites in base sequence, DNA, cytochrome C

• implies close relationship

similarities in morphology/anatomy - similar finches occupying different niches on neighbouring Galapagos islands

MRSA resistance to antibiotics