TOPIC 4 - biodiversity within a community + investigating diversity

Question 1

what is biodiversity?

Answer 1

the variety of living organisms in an area. It can be measured in terms of species diversity.

Question 2

what is species diversity?

Answer 2

number of species in a community.

Question 3

what is ecosystem diversity?

Answer 3

range of different habitats

Question 4

define community.

Answer 4

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

Question 5

what is species richness?

Answer 5

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

Question 6

how do you calculate index of diversity?

Answer 6

D = N(N-1)/{ n(n-1)
n = total number of organisms of one species
N = total number of organisms of all species

Question 7

what impact does agriculture have on species diversity?

Answer 7

• decreases species richness
• monoculture = farming used for 1 species
• destruction of hedgerows - increases area of farmland, destroys habitats = species would lose shelter + food source = die out, migrate
• herbicides/pesticides = reduces plant diversity and bio diversity as pests feeding on crops are killed

Question 8

how can biodiversity be increased in areas of agriculture?

Answer 8

• use hedgerows instead of fences
• grow different crops in the same area
• limit use of pesticides and herbicides

Question 9

name 4 ways in which we can measure genetic diversity?

Answer 9

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

Question 10

what is meant by gene technology?

Answer 10

sampling DNA or mRNA in order to read and compare the base sequence of organisms

Question 11

why do scientists prefer to use gene technology rather than observation?

Answer 11

• simply inferring DNA differences by observation isnt reliable
• characteristics could be coded for by more than one gene

Question 12

what is meant by interspecific and intraspecific variation?

Answer 12

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

Question 13

what is sampling?

Answer 13

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

Question 14

how can a random sample be achieved?

Answer 14

• create a grid for your sample area
• generate coordinates where quadrat can be placed
• repeat until required sample size is reached