The Variety of Life

Question 1

define allele

Answer 1

Different versions of the same gene

Question 2

define Biodiversity

Answer 2

A measure of the variety of life within an area

Question 3

define Species Diversity

Answer 3

no. of different species in a particular area and their relative abundance

(A measure of species richness and species evenness)

Question 4

define species richness

Answer 4

no. different species in a particular area

Question 5

define species evenness

Answer 5

relative abundance of the species in a particular area

Question 6

define Genetic Diversity

Answer 6

A measure of the number of different alleles of genes within a population

Question 7

define Ecosystem

Answer 7

All the living and non-living components of a particular area

Question 8

define Community

Answer 8

All the different living organisms within an ecosystem

Question 9

define Habitat

Answer 9

The area inhabited by a particular species

Question 10

define Niche

Answer 10

The role of a species within it’s habitat

Question 11

define Population

Answer 11

A group of the same species living in the same area

Question 12

define Endemic

Answer 12

found in only one geographical location (at particularly risk of extinction)

Question 13

define Speciation

Answer 13

The development of a new species from a pre-existing species overtime

Question 14

define Gene flow

Answer 14

The exchange of genes via interbreeding

Question 15

define Gene Pool

Answer 15

All the different alleles, of all the different genes of all the individuals within a population

Question 16

2 ways in which biodiversity can be measured

Answer 16

• by measuring species diversity
• by measuring genetic diversity

Question 17

Why is Biodiversity important?

Answer 17

It allows ecosystems to resist changes in the environment

Question 18

5 reasons why a species number might decrease

Answer 18

• endangerment
• natural disaster
• disease
• predation
• human activity

Question 19

4 reasons why a species number might increase

Answer 19

• random mutation leading to speciation
• geographical isolation leading to speciation
• reproductive isolation leading to speciation
• evolution leading to speciation

Question 20

3 ways species diversity can be measured

Answer 20

• via species richness
• via Species evenness/ distribution/ relative abundance
• using Index of diversity {D = N(N-1) / ∑ n(n-1)} TAKES INTO ACCOUNT BOTH SPECIES RICHNESS AND EVENNESS

Question 21

how is species richness measured?

Answer 21

count the total number of different of species within an area {can be estimated using a quadrat}

Question 22

how is species evenness/ distribution/ relative abundance measured?

Answer 22

count number of individuals within each species {can be estimated using a quadrat}

Question 23

2 “synonyms” for species evenness

Answer 23

• distribution of species
• relative abundance of species

Question 24

Why are Ecosystems with high species diversity usuallymore stablethan those with lower species diversity?

Answer 24

Because they are more resilient to environmental changes

Question 25

• How is genetic diversity measured?

Answer 25

Heterozygosity index (H):

  H = no. heterozygotes / Total no. individuals *formula NOT given*

Question 26

does have more heterozygotes make the population more or less diverse?

Answer 26

more.

Question 27

define heterozygosity index

Answer 27

A measure of genetic diversity within a population

Question 28

Why is genetic diversity important?

Answer 28

It can help the population adapt to changes in the environment

Question 29

3 potential biotic changes to the environment

Answer 29

new predators, pathogens and competition

Question 30

3 potential abiotic changes to the environment

Answer 30

temperature, humidity and rainfall

Question 31

• Why is Genetic diversity limited in populations that are verysmall/ isolated? [4]

Answer 31

• Inbreedingoccurs
• higher proportion of homozygotes
• lower genetic diversity
• genetic diseases caused byrecessive allelesbecomemore common