4C Biodiversity

Question 1

Define and explain the term biodiversity

Answer 1

• definition: the variety of organisms in an area
• measures how healthy and diverse an ecosystem is
• can be measured locally or globally eg. pond or desert

Question 2

Define the term habitat

Answer 2

• the place where an organism lives

Question 3

How can biodiversity be measured?

Answer 3

• species richness, the no. of different species in a community, sample different areas of a community and count the amount of species found, doesn’t take population sizes into account (this would be species evenness)
• index of diversity, accounts for the number of different species and frequency of them, considered to be more accurate

Question 4

Describe agriculture

Answer 4

• the act of growing crops or livestock on an area of land
• farmers will try to maximise their yield of crop and many methods they use negatively affect the biodiversity of areas

Question 5

Describe the effect of pesticides and herbicides on biodiversity

Answer 5

• pesticides reduce diversity by killing pest species that feed on crops, they may also kill non-pest species
• herbicides kill weeds, they may eliminate organisms’ food sources

Question 6

Describe the effect of pesticides and herbicides on biodiversity

Answer 6

• pesticides reduce diversity by killing pest species that feed on crops, they may also kill non-pest species
• herbicides kill weeds, they may eliminate organisms’ food sources

Question 7

Describe the effect of clearing hedgerows and woodlands on biodiversity

Answer 7

• this makes room for crops
• reduces the hedge and tree species
• destroys habitats so species must migrate to other areas

Question 8

Describe the effect of monoculture on biodiversity

Answer 8

• this means to only grow a single type of crop in an area
• only species that can live on this single food source will survive

Question 9

What do conservationists try to do and how?

Answer 9

• they try to balance increasing yields of crops while maintaining biodiversity
• they use conservation schemes:
• these may include giving legal protection to endangered species or protecting areas from agricultural or residential development

Question 10

What are SSSIs?

Answer 10

• sites of special scientific interest
• there is lots of these in Cornwall

Question 11

What are AONBs?

Answer 11

• areas of outstanding natural beauty
• eg. the rolling hills of the Malverns

Question 12

Define variation

Answer 12

• the differences that exist between organisms

Question 13

What can variation be caused by?

Answer 13

• genetic factors
• different species will have different genes which causes interspecific variation
• members of the same species will have different alleles which causes intraspecific variation
• environmental factors
• climate, diet and lifestyle can all lead to intraspecific variation

Question 14

What do investigations into variation rely on?

Answer 14

• sampling populations
• often too time-consuming to consider every individual
• small population of total population is investigated and used as a model of the total community

Question 15

Describe how sampling must be used when investigating variation

Answer 15

• must give a representative view of the entire population
• must be random to avoid bias
• this helps to avoid over or under population of a specific member of the population
• this often involves a random number generator