Biodiversity

Question 1

how to assess biodiversity in field work

Answer 1

• grid an area and use a random number generator to select co-ordinates at which to place quadrats (avoid bias)
• count the number of different species and the number of individuals of each species in the quadrat
• repeat 10 times to improve reliability
• calculate using Simpsons index

Question 2

what is the simpsons index and what does it measure

Answer 2

simpsons index reduces species richness and evenness to a single number so that different areas can be compares
D = 1- sum n(n-1) / N(N-1)

Question 3

what is kick sampling

Answer 3

can be used in rivers and the Lincoln index can be used to estimate populations of mobile organisms

Question 4

define what biodiversity measures

Answer 4

refers to the number of different species (species richness) and the number of individuals of each species (species evenness) in a given environment

Question 5

what does it mean by biodiversity varies temporally

Answer 5

the closer to the equator, the more biodiversity there is

Question 6

define polymorphism

Answer 6

polymorphism is the presence of more than one form of type of organism within a single species. this is the result of multiple alleles for a gene.

Question 7

how do we measure polymorphism

Answer 7

it is assessed by determining the number of alleles and the proportion of individuals with that allele. analysis of base sequence in DNA can be carried out on samples of the population to look for variation between individuals. the larger the variation, the higher the genetic diversity

Question 8

describe the process of natural selection

Answer 8

• all individuals in a species have genetic variation (through mutation) that can be inherited
• some variants have a selective advantage
• these variants survive. reproduce and pass their advantageous alleles to their offspring