Chapter 11 Biodiversity

Question 1

Define Biodiversity

Answer 1

The variety of species, genes, and habitats in an area

Question 2

Why is high biodiversity important?

Answer 2

All species interconnected, e.g acting as habitats, food sources, changes in one species in low biodiversity causes large consequences
We rely on balanced ecosystems for resources such as oxygen, food and medicines

Question 3

What are the types of biodiversity?

Answer 3

Habitat- the number of different habitats present in an area
Species- species richness and species evenness
Genetic- variety of genes that make up a species

Question 4

What is species richness and species evenness?

Answer 4

Richness- the number of different species living in an area
Evenness- the number of individuals of each species being similar

Question 5

What is sampling and what is it used for?

Answer 5

Taking a measurement of a limited number of individual organisms present in an area
Used to estimate abundance of organisms, measure a particular characteristic

Question 6

What are examples of sampling?

Answer 6

Random- selecting individuals by chance, mark out a grid and use a random number generator for points
Stratified- divide into subgroups and choose a representative amount for each subgroup, with those members chosen randomly
Non Random including:
Opportunistic- conveniently available for us
Systematic- transect line, samples at specified points. Or a belt, sample spaces in between

Question 7

Why are samples not always reliable?

Answer 7

Sampling Bias- selection based, we could be biased to choose something interesting, reduced by random
Chance- not all samples representative

Question 8

What techniques are used to sample animals?

Answer 8

Pooter- small insects by sucking mouthpiece
Sweepnets- insects in long grass
Pitfall- small crawling invertebrates like slides, spiders in ground, cover to prevent water in
Tree Bearing- invertebrates in trees
Kick sampling- organisms in rivers, kick and sweep

Question 9

How are plants sampled?

Answer 9

Point Quadrats- metal bar where pins can be placed in, which ever plants the pin touches, are part of the sample
Frame Quadrats- frame divided into a grid

Question 10

What are the three ways frame quadrats can be used to determine abundance?

Answer 10

Density- count the number of organisms per Quadrats, = frequency density/ square metre
Frequency- count how many mini squares the species is in, this proportion can be scaled up for whole area, useful for grass
Percentage- by eye see the percentage a species covers in a Quadrats

Question 11

How do you estimate plant and animal size?

Answer 11

Density from Quadrat multiplied by number of quadrats needs in an area
Density + TotalSA/QuadratSA
Animals- capture recapture (number tagged originally x total number caught second time)/ number of organisms marked caught second time

Question 12

What are abiotic factors and give examples?

Answer 12

Non-living conditions in a habitat which have a direct effect on organisms
e.g Windspeed, Light Intensity, Humidity, pH, temperature, Oxygen, Water
More helpful to be detected by sensors has human error, help identify rapid changes, increases precisions and can store data

Question 13

What is the formula for Simpson’s Index of Diversity?

Answer 13

D= 1 - the sum of (n/N)2

Where n= number of organisms of a species
And N= the total number of organisms of all species

The larger the value, the greater the biodiversity

Question 14

What are the main characteristics of a high biodiversity environment?

Answer 14

An unstressful environment
Less specific adaptations
Complex food webs
Not effected greatly by change
A large number of successful species

Question 15

Why is a high genetic diversity important?

Answer 15

Important when there is a change in the environment
A larger number of alleles means there are likely to be some organisms which have advantageous characteristics when faced with a change

Question 16

What factors affect genetic biodiversity?

Answer 16

Mutations to produce new alleles
Selective and Captive breeding, artificial cloning
Natural selection
Gene flow, Genetic Bottlenecks, and Genetic Drift
Founder effect

Question 17

What is gene flow? What are genetic bottlenecks?

Answer 17

Gene Flow- alleles transferred between two populations
Genetic Bottlenecks- a change in the environments reduces gene pool, fewer alleles present as only those with advantageous have survived. Reduced g.b as all members of population fro ma few original survivors

Question 18

What is genetic drift?

Answer 18

Due to the random nature of passing alleles, alleles may disappear from a population, particularly impactful when a population size is small.

Question 19

What is the founder effect?

Answer 19

When a new population is formed due to isolation of a few members of a species, the genotype and gene pool of these few organisms will have define the genotype of the next generations
Means alleles which may have been less frequent in the old population maybe vary in allele frequency of the new population, if one of the founders has that rare allele

Question 20

How can you measure the genetic biodiversity of a population?

Answer 20

Through polymorphic genes- when there exists multiple alleles for a gene

Proportion of polymorphic= n.of polymorphic/ total number of genes

Larger proportion, greater genetic biodiversity

Question 21

How has deforestation and agriculture reduced biodiversity?

Answer 21

Deforestation- removing large forests for wood and space
Lower number of trees, less habitats. If a specific type of tree chosen, also reduces biodiversity
Agriculture- more farming of one plant species to maximise profit
Remove hedgerows which are a habitat, pesticides and herbicides also decrease species, which remove others food source

Think about the levels of biodiversity- species, habitat, and genetic

Question 22

How does monoculture reduce biodiversity?

Answer 22

Only one species planted - few animals species as less habitats
Mineral depletion

Question 23

How does climate change reduce biodiversity ?

Answer 23

Increasing global temperatures, sea levels
Decreasing glaciers and snow cover, increased precipitation
Extinctions of arctic animals
Flooding reducing habitats, also mixing salt and fresh water
Unhealthy advantage to xerophytes, dominate ecosystem
Insect populations changing

Question 24

What are aesthetic reasons to maintain biodiversity?

Answer 24

Enriches our lives with beaches, woodlands, parks
Help reduce recovery times for patients when in nature

Question 25

What are economic reasons for maintaining biodiversity?

Answer 25

Soil erosion and desertification will reduce the ability to grow crops, maintaining biodiversity reduces this Crops may go extinct if not maintained. Monocultures deplete soil of minerals so farmers increasingly reliant on fertilisers, herbicides, pesticides Non sustainable produces will eventually cause industry to collapse as they will run out, so we are trying to reduce this Some organisms go extinct before finding a commercial use e.g medicines Tourism Wild plants provide genes for cross breeding to introduce desirable qualities e.g disease resistance, increased yield

Question 26

What are ecological reasons to maintain biodiversity?

Answer 26

Removal of keystone species, small numbers but very large impact, means ecosystem destroyed Rely on organisms, e.g pollinators And wild plants produce gene pool that can be used to introduce desirable characteristics into commercial plants, cross breeding

Question 27

What is conservation and what are the aims of it?

Answer 27

Human action and careful management of the environment and natural resources Increased chance of survival, increase genetic diversity in species,

Question 28

What are the two types of conversation?

Answer 28

In situ- in natural habitat, so maintains genetic biodiversity, evolutionary adaptations and interdependence Ex situ- out side of natural habitat, more drastic

Question 29

What do extinct, extinct in the wild, endangered, and vulnerable mean?

Answer 29

Extinct- organism not found anywhere Extinct in the wild- only found in captivity Endangered- in danger of extinction Vulnerable- species likely to become endangered

Question 30

What is sustainable development?

Answer 30

Economic development that meet the needs of people today, without limiting the ability of future generations

Question 31

How do wildlife reserves help endangered animals?

Answer 31

Controlled grazing- time restrictions to allow species to recover Restricting human access, reducing poaching Removing invasive species, reintroducing helpful species, feeding the animals Halting succession- the process of an early colonising species being released by a more stable species

Question 32

How do botanical gardens and seed banks help maintain biodiversity?

Answer 32

Species given resources, soil nutrients and ideal temperatures in botanical Seed banks effectively a gene bank, storing genetic material of seeds, but some seeds die in the process, prolongs germination

Question 33

What is captive breeding? What are the advantages and disadvantages of this practice?

Answer 33

Offspring produced in human controlled environments, with shelter and food and an absence of predators However: Reduces genetic biodiversity as limited members- overcome by genetic catalogues to prevent the same DNA in offspring, including artificial insemination Cannot be released into the wild as loses behaviours such as gathering food, disease resistance Genes may be too different to breed with outside animals

Question 34

What is the IUCN, and how does it help maintain biodiversity?

Answer 34

International Union of Conservation of Nature Securing agreements, and help create conventions on International Trade

Question 35

How did the Rio convention help maintain biodiversity?

Answer 35

UNFCCC go help stabilise greenhouse gases UNCCD to combat desertification Countryside Scheme to pay farmers when they sustain biodiversity, including restoring land, later replaced

Question 36

What is a key stone species?

Answer 36

A species which has a significant impact upon an ecosystem, disproportionally compared to size of the population Lots of organisms depend on keystone species

Question 37

What does CITES do?

Answer 37

Ban trade of endangered animals

Question 38

How can you improve using a transect line to compare the species present in each area?

Answer 38

Use multiple transect lines, and maybe use stratified Repeat on a several days, all at the same time Find a way to ensure you are not spotting the same animals multiple times in one transect

Question 39

Why might having small scattered populations of an endangered species increase the likelihood of extinction? How can zoos increase the survival of a species?

Answer 39

Harder to find a mate, reduced gene pool, cannot cope if there are changing selection pressures Captive breeding Promote awareness and need for conservation

Question 40

What are marine conversation zones?

Answer 40

Areas which preserve coral reefs Create areas of refuge where populations can build up and repopulate adjacent areas Reduce destruction from overfishing

Question 41

How can a tullgren funnel be used?

Answer 41

Funnel with a beaker below Gauze in the funnel with leaf litter and a lamp above to attract insects Insects fall through funnel into beaker below

Question 42

Why is it important to keep rare breeds of organisms alive?

Answer 42

To help maintain biodiversity Genetic resource if we need to use the alleles e.g for genetic engineering and selective breeding to promote this trait, if the trait is useful in these changed conditions

Question 43

What factors may make a breed of (sheep) endangered? General things to consider

Answer 43

Small populations Results in inbreeding and small gene pools Likely genetic drift has occured So unable to keep breed alive is an unfavourable change in environment occurs

Question 44

Why is biomass sometimes used instead of counting organisms e.g for plants and fungi?

Answer 44

Difficult to individually identify each organism Too time consuming