Biodiversity-4.2

Question 1

Define biodiversity

Answer 1

A measure of the variation found in the living world

Question 2

Define a species

Answer 2

A group of individual organisms that are very similar in appearance ,anatomy, physiology,biochemistry and genetics. Whose members are able to reproduce freely to produce fertile offspring.

Question 3

What is a habitat?

Answer 3

A place where an organism lives

Question 4

What is habitat biodiversity?

Answer 4

-the range of habitats in which different species live
-e.g. sand dunes, woodland,meadows,streams

Question 5

What contributes to species biodiversity?

Answer 5

Species richness and species evenness

Question 6

What is genetic biodiversity?

Answer 6

-different breeds within a species

Question 7

How can random sampling be carried out?

Answer 7

-sample sites are randomly selected
-e.g.
.using randomly generated numbers as coordinates for your samples

Question 8

What is the advantage of random sampling?

Answer 8

-ensures that the data is not biased by selective sampling

Question 9

What are the disadvantages of random sampling?

Answer 9

-may not cover all areas of habitat equally
-species with a low presence may be missed, leading to an underestimate of biodiversity

Question 10

What are three examples of non-random sampling?

Answer 10

-opportunistic
-stratified
-systematic

Question 11

How is opportunistic sampling carried out?

Answer 11

-when the researcher makes sampling decisions based on prior knowledge or during the process of collecting data
-the researcher may deliberately sample an area that they know or can see contains a particular species

Question 12

What are the advantages of opportunistic sampling?

Answer 12

-easier and quicker than random sampling

Question 13

What are the disadvantages of opportunistic sampling?

Answer 13

-the data may be biased
-can lead to an overestimate of biodiversity or an overestimate of a particular species (e.g. if it is very colourful?

Question 14

How is stratified sampling carried out ?

Answer 14

-dividing a habitat into areas that appear different and sampling each area separately

Question 15

What are the advantages of stratified sampling?

Answer 15

-ensures that all different areas of habitat are sampled and species are not underrepresented due to the possibility that random sampling misses certain areas

Question 16

What are the disadvantages of stratified sampling?

Answer 16

-may lead to the over-representation of some areas in the sample
-e.g. a disproportionate number of samples are taken in small areas that look different

Question 17

How is systematic sampling carried out?

Answer 17

-when samples are taken at fixed intervals across the habitat
-e.g. line transects and belt transects

Question 18

What is an advantage of systematic sampling?

Answer 18

-very useful when the habitat shows a clear gradient in some environmental factors
-such as getting drier further from a pond

Question 19

What is a disadvantage of systematic sampling?

Answer 19

-only the species on the line or within the belt can be recorded
-other species may be missed, leading to an underestimate of biodiversity

Question 20

What is species evenness?

Answer 20

• a measure of how evenly represented the species are
  -to measure this you need to carry out a quantitative survey

Question 21

What is species richness?

Answer 21

-a measure of how many different species are present
-to measure you need to count all the species present in a habitat

Question 22

How can you interpret the value of Simpson’s index?

Answer 22

-a high value indicates a diverse habitat-the habitat tends to be more stable and able to withstand change

-a low value indicates a habitat dominated by a few species- a small change to the environment (e.g. a disease, a new predator) that affects one of those species species could damage or destroy the whole habitat.

Question 23

What is a quadrat?

Answer 23

-square frame that is used to define the size of the sample area often 50cm or 1m on each side
-they are suitable for sampling plants or slow moving animals
-quadrats can be places in a habitat randomly or a long a transect

Question 24

Measurements within a quadrat might include…

Answer 24

-the number of species present
-number of individuals of a species present , i.e. species abundance
-the presence/absence of a species
-the percentage cover of a species (you can use a point frame to help with this )

Question 25

What is a point frame?

Answer 25

-you can measure percentage cover using a point frame -it is a frame holding a number of long needles/pointers -you lower the frame into the quadrat and record any plant touching the needles -if frame has 10 needles and you use it 10 times then you will have 100 readings so each plant touching the needle will have 1% cover (it is possible to find you have a high percentage cover in some habitats) -do not forget to record bare ground -it may be best to use a point frame at regular intervals across the quadrat

Question 26

What is a transect?

Answer 26

- a line along which samples can be taken -they are used during systematic sampling to assess how abundance and distribution of organisms is affected by changes in abiotic factors across a habitat -transect lines are laid out across a habitat along the gradient that is to be investigated

Question 27

How do you do a line transect?

Answer 27

-lay out a measuring tape in a straight line across the sample area -at regular distances along the tape e.g. every 1metre, record the identity of the organisms that touch the line

Question 28

How do you do a belt transect?

Answer 28

-lay out a measuring tape in a straight line across the sample area -place quadrats at regular intervals (interrupted belt transect) -or continuously (continuous belt transect) along the tape -record the abundance or percentage cover of each species within each quadrat

Question 29

What are sweep nets?

Answer 29

-strong nets made from a material with very small holes -the nets can be swept across vegetation e.g. grass or tree branches to catch flying insects and insects that live on leaves -after sampling the insects in the net can be counted and identified e.g. empty the contents onto a white sheet to identify them taking care that the insects do not crawl or fly away - you can use a pooter to collect insects before they fly away

Question 30

What is a pitfall trap?

Answer 30

-a trap set in the soil to catch small animals -they are small containers that are buried in the soil so that the rim is just below the surface -ground-dwelling invertebrates fall into the trap as they walk along the ground and then cannot climb out again -the trap should contain a little water or scrunched up paper to stop animals crawling out again, also some leaf litter or newspaper can be used to allow smaller insects to hide from larger predatory insects -the trap should be sheltered from the rain so it does not fill up e.g a canopy

Question 31

What is a pooter ?

Answer 31

-small plastic or glass containers with two tubes extending from the lid -the tubes can be used to suck up small invertebrates -the first tube is placed over the insect and the second tube is used to create suction -once inside the container the sampled organisms can be easily viewed and identified

Question 32

What is the equation for the mark-release-capture method?

Answer 32

N = (n1 × n2) ÷ m2 -N=population estimate -n1=number of marked individuals released -n2=number of individuals in the second sample (marked and unmarked) -m2=number of marked individuals in the second sample

Question 33

What do the symbols stand for in the Simpson’s diversity index equation?

Answer 33

-D= Simpson’s diversity index -N= total number of organisms of all species/ total percentage cover for plants -n=number of organisms of a particular species/ percentage cover for plants

Question 34

What is the equation for polymorphic gene loci?

Answer 34

Proportion of polymorphic gene loci = Number of polymorphic gene loci ———————————————————— Total number of loci

Question 35

What is a locus in relation to genetics?

Answer 35

-the position of that gene on a chromosome

Question 36

What is a polymorphic gene locus?

Answer 36

-a locus that has more than 2 alleles

Question 37

How do you calculate genetic diversity?

Answer 37

Question 38

How does human population growth affect biodiversity?

Answer 38

-increases the demand for resources from the environment

Question 39

How does agriculture affect biodiversity?

Answer 39

-reduces biodiversity by monoculture ( a crop consisting of one strain of one species) -use of herbicides and pesticides -deforestation to clear land for crops

Question 40

How is climate change a factor that affects biodiversity ?

Answer 40

-climate change means significant, long-lasting changes in weather patterns -it is causing animals to migrate or to die

Question 41

What are the 2 ecological reasons for maintaining biodiversity?

Answer 41

-protecting keystone species- species that have a larger impact on the ecosystem than others, when these species are lost there are several knock-on effects. E.g elephants -the way they graze helps to maintain ecosystem, elephant dung provides a habitat for many important fungi and insect species. When elephant population decreases there is a negative impact on the savannah -maintaining genetic resources

Question 42

What is the economic reason for biodiversity?

Answer 42

-reducing soil depletion (the loss of soil fertility caused by the removal of minerals through continuously growing monoculture plants)

Question 43

What is the aesthetic reason for biodiversity?

Answer 43

-protecting landscapes

Question 44

What is conservation in situ ?

Answer 44

-carrying out active management to maintain the biodiversity in the natural environment -e.g. marine conservation zones and wildlife reserves

Question 45

What are marine conservation zones?

Answer 45

-areas of the sea set aside to conserve the diversity of species and habitats

Question 46

What are wildlife reserves?

Answer 46

-areas set aside for the conservation of species or habitats

Question 47

What are the advantages and disadvantages of in situ conservation ?

Answer 47

ADVANTAGES -plants and animals are conserved in their natural environment -allows management of these areas to ensure that ecological integrity is maintained -facilitates scientific research DISADVANTAGES -endangered habitats may be fragmented and each small area may not be large enough to ensure survival -population may have already lost much of its genetic diversity -the conditions that caused the habitat or species to become endangered may still be present

Question 48

What is conservation ex situ?

Answer 48

-conservation outside the normal habitat of the species E.g- seed banks, botanic gardens and zoos

Question 49

What are the advantages and disadvantages of ex situ conservation?

Answer 49

ADVANTAGES -organisms protected from predators and poaching -health of individuals can be monitored and medical assistance given as required -genetic diversity of the population can be measured -animals can be bred to increase the numbers of an endangered species -selective breeding can be carried out to increase genetic diversity DISADVANTAGES -the organisms are living outside their natural habitat -a captive population is always likely to have a limited genetic diversity -the correct conditions for survival may be difficult to achieve -even if reproduction is successful the animals have to survive reintroduction into the wild where they need to find food and survive predators -when reintroduced there can be difficulties with acceptance by the existing wild members of the species

Question 50

What was the Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) and what are its aims?

Answer 50

-an international agreement between the majority of governments in the world -first agreed in 1973 -overall aim is to ensure that international trade in specimens of wildlife does not endanger their survival. It aims to: .regulate and monitor international trade in selected species of plants and animals .ensure that international trade does not endanger the survival of populations in the wild .ensure that trade in wild plants for commercial purposes is prohibited .ensure that trade in artificially propagated plants is allowed, subject to permit .ensure that some slightly less endangered wild species may be traded subject to a permit, as agreed between the exporting and importing countries

Question 51

What are the concerns surrounding CITES ?

Answer 51

When the trade of a certain endangered species becomes illegal, its price increases The increased economic value of the species can be a major incentive for people to break the law

Question 52

What was the Rio Convention on Biological Diversity (CBD) ?

Answer 52

-The Convention on Biological Diversity (CBD) was signed at the Earth Summit in Rio de Janeiro in Brazil in 1992 -The convention had three main goals: .The conservation of biological diversity by use of a variety of different conservation methods .The sustainable use of biological resources .The fair and equitable sharing of benefits arising from genetic resources The countries that signed the convention agreed to design and implement national strategies for the conservation and sustainable use of biodiversity, as well as to organise international cooperation and further international meetings

Question 53

What was the Countryside Stewarship Scheme?

Answer 53

-introduces in England in 1991 applied to land that was not considered to be in an environmentally sensitive area. Payments were made to farmers to enhance and conserve English landscape -aims were to -> improve the natural beauty and diversity of the countryside -> enhance , restore and re-create targeted landscapes, their wildlife habitats and historical features ->improve opportunities for public access

Question 54

What was the Countryside Stewardhip Scheme replaced by and what are the aims of this other scheme ?

Answer 54

This scheme was replaced by the Environmental Stewardship Scheme (ESS) in 2005 In order to qualify for the scheme, farmers and private landowners have to: -Provide and protect valuable wildlife habitats such as ponds, hedgerows and buffer zones surrounding farmed areas -Ensure their land is managed well, maintaining its traditional character -Protect any natural resources or historic features present on their land -Conserve any traditional crops or livestock present on their land -Provide visitor opportunities so people can learn about the countryside and how important it is in sustaining biodiversity

Question 55

Captive breeding programmes with D.sumatrensis have been unsuccessful Suggest one other way in which zoos can contribute to the conservation of the Sumatran rhinoceros (1 mark)

Answer 55

-education/ awareness (Support for/promote conservation projects/research)