Biodiversity within a community

Question 1

What is biodiversity?

Answer 1

• The variety of living organisms
• It can be measured in terms of species diversity (number of species in a community), ecosystem diversity (range of different habitats) and genetic diversity

Question 2

Define community

Answer 2

All the different species that live in one area and interact with each other

Question 3

How do you calculate index of diversity (d)?

Answer 3

d = N(N - 1) / En(n - 1)

• N = total number of organisms of all species
• n = total number of organisms of each species
• E = sum of

Question 4

What impact does farming have on species diversity?

Answer 4

Decreases species richness

• Farmland is typically used for only 1 species (monoculture)
• Use of pesticides/herbicides

Question 5

What impact does farming have on genetic diversity?

Answer 5

Decreases

- Farmers select for certain characteristics, which reduces number of different alleles in the population

Question 6

How can biodiversity be increased in areas of agriculture?

Answer 6

1. Use hedgerows instead of fences
2. Grow different crops in the same area, or rotate crops around after a season
3. Limit use of pesticides and herbicides

Question 7

Name 4 ways we can compare genetic diversity between organisms

Answer 7

1. Frequency of observable characteristics
2. Base sequence of DNA
3. Base sequence of mRNA
4. Amino acid sequence

Question 8

What is meant by gene technology?

Answer 8

• Sampling DNA or mRNA in order to read and compare the base sequence of organisms
• Alternatively the amino acid sequence can be studied as this will also provide information on the organism’s mRNA and DNA sequences

Question 9

Why do scientists prefer to use gene technology instead of observation?

Answer 9

• Simply inferring DNA differences by observing an organism’s characteristics is not reliable
• Characteristics could be coded for by more than one gene, or could be influenced by the environment

Question 10

What is meany by interspecific and intraspecific variation?

Answer 10

• Interspecific = differences between individuals of different species
• Intraspecific = differences between individuals of the same species

Question 11

What is sampling?

Answer 11

Selecting a group of individuals to measure that will represent the whole target population

Question 12

How can a random sample be achieved?

Answer 12

• Create a grid for sample area, and randomly generate coordinates where a quadrat or transect can be placed
• Repeat until required sample size is reached