Biodiversity

Question 1

What is biodiversity

Answer 1

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

Question 2

How is biodiveristy affected

Answer 2

• it varies spatially -closer the equator the more biodiverity there iss
• varies temporally through time biodiversity varies eg mass extinctions reduce biodiversity
• human activites affect biodiversity eg habitat destruction and climate change

Question 3

How is biodiveristy assesed in field work

Answer 3

• grid an area and use a random number generator to select co ordinates at which to place quadrats to avoid bia
• count the number of different species and the number of indiciduals of each species in quadrat
• repeat 10 times to improve reliability

Question 4

What is the Simpsons diversity index

Answer 4

• reduces species richness and eveness to a single number so that differenct areas can be compared
• kick sampling can be used in rivers and the licoln index used to estimate population of mobile organisms

Question 5

What is polymorphism

Answer 5

• prescence of more than one form or type of organism within a single species
• result in multiple alleles for a gene
• asesed by determining the number of alleles and the proportions of individuals with that allele

Question 6

Why is assessing diversity with genetic material difficult

Answer 6

• counting every allele in a population is difficult
• analysis of base sequences in DNA can be carried out on samples of the population to look for variation between individuals
• larger variation higher the genetic diveristy

Question 7

How is biodiversity generated

Answer 7

• natural selection
• all individuals in a species have genetic variation through mutation that can be inherited
• some variants have a selective advantage if a selection pressure is predation a better camoflages individual has an advantage over less a well camoflages one
• these variants survive reproduce and pass their advantageous alleles to their offspring

Question 8

What does natural selection lead to

Answer 8

• leads to organisms being adapted to their environment

Question 9

What are adaptations

Answer 9

• can be morphological , physiological and behavioural
• morphological - physical