Biodiversity + Investigating diversity

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) / {n(n-1)
N= total no of organisms of all species
n= total no of organisms of each species
{ = 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 four 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 unreliable;
the characteristics could be coded for by more than one gene, or could be influenced by the environment.

Question 10

What is meant 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 your sample area, and then randomly generate coordinates where a quadrat or transect can be placed.
Repeat until required sample size is reached.

Question 13

How do you obtain data to give a more precise value for the index of diversity?

Answer 13

1. Take more samples and find mean
2. Obtain a random sample
3. Use a larger sample

Question 14

What is the difference between species richness and an index of diversity?

Answer 14

Species richness measures only number of different species but does not measure number of individuals.

Question 15

What is genetic diversity?

Answer 15

the number of different alleles of genes in a population.