Topic 3.3 Biodiversity

Question 1

What is biodiversity?

Answer 1

The variety of living organisms. it can be assesed at different levels; within a habitat at the species level (index of diversity) or within a species at the genetic level (variety of alleles).

Question 2

How do you calculate index of diversity (d )?

Answer 2

d = (N(N-1)) / (Σn(n-1))

Where:
* N = total number of organisms of all species
* n = total number of organisms of each species
* Σ = sum of

The greater the value of d the greater the biodiversity

Question 3

What is an allele?

Answer 3

Different forms of a particular gene, found at the same locus (position) on a chromosome. A single gene could have many alleles.

Question 4

How does a species’ variety of alleles relate to biodiveristy?

Answer 4

Within a species, all of the organsisms ahve the same gene pool. However each organism will have a different combination of alleles. A wider variety of alleles within a species increases diversity.

Question 5

Give reasons why we should maintain biodiversity

Answer 5

• More stable, resillient populations
• Ecotourism opportunites
• Provides sources of medicines
• Stabilise soils
• Increase the gene pool

Question 6

Define conservation

Answer 6

The protection and management of species and habitats, in order to maintain biodiversity. Can be in-situ (in an organism’s habitat) or ex-situ (outside an organism’s habitat).

Question 7

Give examples of in-situ conservation

Answer 7

• Protected habitats e.g. National Parks that protect the species there from depletion
• Education programmes that teach people about the importance of biodiversity

Question 8

Give the advantages and disadvantages of in-situ conservation

Answer 8

Positives:
*Protects more than one species, cheap, few resources required.

Negatives:
*Hard to enforce legislation, populations may still decline

Question 9

Give examples of ex-situ conservation

Answer 9

• Zoos where endangered species can be carefully bred to increase genetic diversity and prevent inbreeding
• Seed banks store seeds carefully to keep them viable, to prevent certain species from going extinct

Question 10

Give advantages and disadvantages of ex-situ conservation

Answer 10

Positives:
* Requires little space, eliminates poachers and predators
Negatives:
*Expensive, can’t fully recreate natural habitat, disease spreads quickly

Question 11

What three roles do zoos have in conservation?

Answer 11

1 - Education, including about:
~ illegal trade in animals and products
~ the need for biodiverstiy
2 - Scientific research, including into:
~ control of diseases
~ behaviour - to understand animals’ needs
~ techniques to improve breeding
3 - Captive breeding programmes, to:
~ increase numbers, thus reducing the risk of extinction
~ release animals into the wild
~ maitain genetic diversity

Question 12

Give concerns about animals in zoos

Answer 12

• Animals behave unnaturally
• Most species are not endangered but are kept for tourism
• Animals may be kept in poor conditions or conditions they are unsuited to
• Exhibition may reduce wild populations

Question 13

How is biodiversity maintained in zoos?

Answer 13

• Not allowing organisms to repeatedly breed with the same partner
• Select partners, possibly by adding a potential partner to the cage, using invitro ferilisation or inter-zoo swapping
• Keep a record/ database of individualsin captivity and their breeding history, e.g. stud books, so that the choice of partners is controlled

Question 14

Why are seeds stored instead of plants?

Answer 14

• Less space is required so more species can be held in the available space
• Most plants produce large numbers of seeds so collecting small samples is unlikely to damage the wild population
• They are easier to store because they are dormant
• It is more cost effective