4.6 & 4.7 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, ecosystem diversity and genetic diversity

Question 2

What is a community?

Answer 2

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

Question 3

What is species diveristy?

Answer 3

refers to the number of different species and the number of individuals of each species within any one community

Question 4

What is genetic diversity?

Answer 4

refers to the variety of genes possessed by the individuals that make up a population of a species

Question 5

What is ecosystem diversity?

Answer 5

refers to the range of different habitats, from a small local habitat to the whole of the earth

Question 6

What is species richness?

Answer 6

the number of different species in a particular area at a given time

Question 7

How do you calculate index of diversity?

Answer 7

d = N(N-1)/∑n(n-1)
N = total number of organisms of all species
n = total number of organisms of each species
∑ = sum of

Question 8

What impact does agriculture have on species diversity?

Answer 8

decreases species richness
- farmland is typically used for only 1 species (monoculture)
- use of pesticides/herbicides

Question 9

What impact does farming have on genetic diversity?

Answer 9

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

Question 10

How can biodiversity be increased in areas of agriculture?

Answer 10

• use hedgerows instead of fences
• grow different crops in the same area, or rotate crops around after a season
• limit the use of pesticides and herbicides

Question 11

Name 4 ways we can compare genetic diversity between organisms

Answer 11

• frequency of observable characteristics
• base sequence of DNA
• base sequence of mRNA
• amino acid sequence

Question 12

What is meant by gene technology?

Answer 12

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 organisms mRNA and DNA sequences

Question 13

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

Answer 13

simply inferring DNA differences by observing an organisms characteristic is not reliable; the characteristics could be coded for by more than one gene, or could be influenced by the environment

Question 14

What is meant by interspecific and intraspecific variation?

Answer 14

interspecific = differences between individuals of different species
intraspecific = differences between individuals of the same species

Question 15

What is sampling?

Answer 15

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

Question 16

How can a random sample be achieved?

Answer 16

create a grid for your sample area and then randomly generate coordinates where a quadrat or transect can be placed. Repeat until required sample size is reached