Biodiversity

Question 1

Define “species richness”

Answer 1

The number of different species in a habitat

Question 2

What is the relationship between species richness and number of different species?

Answer 2

The higher the number of different species the higher the species richness

Question 3

What is the problem of measuring with species richness?

Answer 3

Gives no indication of the abundance of each species

Question 4

What are the two ways of measuring biodiversity?

Answer 4

• Species diversity

- Genetic diversity

Question 5

What is species diversity?

Answer 5

The number of different species and the abundance of each species in an area

Question 6

What is genetic diversity?

Answer 6

The variation of alleles in a gene pool of a species/population

Question 7

What is a better way to measure species diversity than species richness?

Answer 7

Biodiversity index

Question 8

What is the relationship between biodiversity index and species diversity?

Answer 8

The higher the BI, the higher the species diversity

Question 9

What are the two ways to investigate genetic diversity?

Answer 9

• Phenotype

- Genotype

Question 10

How can phenotype be used to investigate genetic diversity? 3

Answer 10

• Different alleles code for slightly different versions of a phenotype
• By observing different phenotypes, the diversity of alleles in a population can be seen
• The larger the number of different phenotypes, the greater genetic diversity

Question 11

How can genotype be used to investigate genetic diversity? 4

Answer 11

• Samples of an organism’s DNA are taken and sequence of base pairs analysed
• Order of bases in different alleles is slightly different
• By sequencing DNA, number of different alleles for a species can be determined
• The larger the number of different alleles, the greater the genetic diversity

Question 12

State the heterozygosity index

Answer 12

Number of heterozygous/number of individuals in the population

Question 13

How can heterozygosity index be used to determine genetic diversity? 2

Answer 13

• Heterozygotes have two different alleles at a particular locus
• Higher heterozygosity index (proportion) = higher genetic diversity

Question 14

How are new alleles generated?

Answer 14

Mutations in genes

Question 15

What are the assumptions of the Hardy Weinberg equation?

Answer 15

• Frequency of alleles in a population won’t change from one generation to the next
• Must be a large population
• No immigration/emmigration
• No mutations
• No natural selections

Question 16

If the allele frequency changes between generations change what does it mean?

Answer 16

One of the assumptions of the Hardy Weinberg has changed e.g there is natural selection