Biodiversity Flashcards
Explain the importance of sampling in measuring the biodiversity of a habitat. f212 june 2015 q3bi
impossible / difficult , to count every individual;
sample provides an estimate;
sample representative (of whole area); [idea that
counting every individual is too time consuming]
Why was it important to take samples in fenced and unfenced areas? f212 june 2015 q3bii
to compare (the two areas); (presence or absence of) roe deer is independent variable; controlling variables other than roe deer; [one area acts as a control/ to see the effect of the roe deer]
Explain the difference between species richness and species evenness and why both measurements are needed to assess biodiversity.(3mks) f212 june 2015 q3biii
(species) richness is number (how many) of species (in a habitat);
(species) evenness is , abundance / number of individuals of , each / every / all , species (in a habitat); [evenness is relative , numbers / abundance, of (each) species]
idea that both (richness and evenness) are needed to
reveal dominance;
high biodiversity associated with high species richness
and high species evenness;
In areas where the population of roe deer was high, the Simpson’s Index of Diversity was low for shrubs (medium-height plants) and was also low for woodland birds. Roe deer eat plants. Most woodland birds do not eat plants.
Suggest one reason why a large roe deer population might decrease the diversity of woodland birds. f212 june 2015 q3biv
plants are , the basis / AW , of (all) food chains;
shrubs / plants , are food for , insects / animals , that birds eat;
shrubs might provide , nesting sites / cover / protection / habitat; [in the context of birds, or animals that birds
eat]
Outline the significance of a low value of Simpson’s Index of Diversity.(2mks) f212 june 2015 q3bv
(habitat) dominated by, one / few / AW, species; [high number of one species]
ecosystem / habitat , is , unstable / less likely to cope with change; [in the context of an example of
environmental change; a change in one species with have a large effect on the , ecosystem / habitat / food chain]
In the past, the roe deer’s main natural predator in Britain was a large carnivore of the cat
family, the Eurasian lynx, Lynx lynx. The lynx became extinct in Britain around 1000 years
ago.
Populations of Eurasian lynx still survive in parts of mainland Europe.
Plans are being considered to re-introduce the Eurasian lynx from these European populations
to the wild parts of Britain to improve biodiversity.
(i) Suggest one reason why some people might object to this re-introduction. f212 june 2015 q3ci
danger to, humans/ local wildlife/ domestic animals/ deer; [danger to existing food chains]
environment may no longer be suitable for lynx;
The Iberian lynx and Eurasian lynx were once classified within the same species, based
on their observable features.
In the last 10 years, the Iberian lynx has been re-classified as a separate species within the genus
Lynx, on the basis of its phylogeny.
Define the term phylogeny and explain how phylogeny is related to classification. Use the two lynx species as examples.(4mks) f212 june 2015 q3cii
1 (phylogeny is) the evolutionary , relationship between / history of , organisms / species; [reasonable description of evolutionary, history / relationship, e.g. changes in ancestral organisms]
2 phylogeny is the basis of classification ;
3 example of molecular evidence used to classify; [ base sequence / amino acid sequence/ DNA / cytochrome C / haemoglobin / ATPase (used to
classify)]
4 species / organisms , within the same group have shared , phylogeny / evolutionary history / common ancestor;
5 phylogeny of L. lynx and L. pardinus are sufficiently , different to have been placed in separate species
/ similar to have been placed in same genus;
Suggest why it is only in the last 10 years that the Iberian lynx has been classified as a separate species. f212 june 2015 q3ciii
modern / new / better , technology (to distinguish between closely related species); [named example, e.g. DNA sequencing]
more , molecular / biochemical / DNA / genetic, evidence;
Outline three reasons why it is important to conserve the Iberian lynx. f212 june 2015 q3civ
1 impact on food chain(s); [controlling deer population;
top carnivore / top predator / keystone species / it might compete with existing species]
2 right to exist / duty of humans to care for other
species / ethical reason / preserving species for
future generations;
3 aesthetic reason; [beautiful creatures / nice to look at]
4 economic reason / tourism / might provide useful resource;
Wheat is an important food crop in many European countries. Developments in farming allowed
the yield of wheat produced by farms in the UK to increase rapidly in the second half of the
20th century.
Fig. 4.1 shows the increase in the yield of wheat from 1947 to 1992. The graph also shows the
increase that is thought to be as a result of the development of new varieties through selective
breeding.
Explain how the selective breeding that led to this increased yield could have been done. (4mks)
f212 june 2015 q4b
1 crossbreed / breed / interbreed , high-yielding, wheat
plants / individuals; [breed high-yielding individuals;
‘mate / reproduce’ or ‘breed // description of high-
yielding plant, e.g. more, ears / grain / seed / wheat; if only one of the plants is high-yielding]
2 assess / test / measure, yield;
3 crossbreed, selected / best / high-yielding, offspring;
4 over generations; [several / a few generations]
5 marker assisted selection / prevent self-pollination /
genetic screening / prevent unwanted (cross) pollination; [ descriptions; prevent self-fertilization]
State 2 developments, other than selective breeding, that could account for the total
increase in wheat yield per hectare. f212 june 2015 q4c
(use of) fertiliser;
(use of) pesticide / fungicide / insecticide; [selective herbicide]
improved technology; [better harvesting technology]
The Royal Botanic Gardens at Kew plays an important role in plant conservation. One plant
that has been conserved at Kew is the world’s smallest water lily, the thermal lily, Nymphaea
thermarum. In its natural habitat, the thermal lily grows in hot water springs in central Africa.
Explain why it is sometimes necessary to conserve a plant species, such as N. thermarum, outside its natural habitat (ex situ). (3mks) (f212 June 14 q3b)
1) (natural) habitat / ecosystem , lost due to / destroyed
by / under threat from , climate change /
(named) human activity ; [natural disaster / deforestation , as reason for habitat loss]
2) number / population , (in natural habitat) is very low ; [IGNORE reference to , extinct / endangered]
3) idea that in the wild, (sexual) reproduction is difficult (if numbers are low) ; [e.g. fertilization can be carried out using a paintbrush]
4) (breeding ex situ can) maintain , the gene pool /
genetic / allelic , diversity;
5) idea that allows protection from , grazers / herbivores / plant collectors / competing species ; [habitat contains organisms that are a threat; otection from , predators / poachers / hunters]
6) idea of protection from , pathogen / parasites / disease; [pests]
The Royal Botanic Gardens at Kew plays an important role in plant conservation. One plant
that has been conserved at Kew is the world’s smallest water lily, the thermal lily, Nymphaea
thermarum. In its natural habitat, the thermal lily grows in hot water springs in central Africa.
The Royal Botanic Gardens also manages the Millennium Seed Bank, which aims to store
seeds from one quarter of all plant species.
Give three advantages of conserving plant species as seeds and not as adult plants. (F212 June 14 q3c)
1) can be collected with minimal damage to (wild),
population/ habitat/ ecosystem;
2) take up little space / larger numbers can be stored; [easier to store a large amount]
3) can store great(er) , genetic / allelic , diversity;
4) low(er) maintenance / manpower costs; [‘cheaper’ only if supported by an explanation; easier to keep unqualified; less labour-intensive]
5) easy / cheaper, to transport;
6) idea of remaining viable for long periods; [e.g. kept dry so that they do not rot / regular germination and new seed production; ‘last a long time’ unqualified; ‘stay , alive / fertile , for a long time’]
7) less , susceptible / vulnerable , to, disease / pests /
environmental change; [the adult plant might have a disease]
8) idea that prevents fertilisation by undesired pollen;
When measuring the biodiversity of a habitat, it is difficult to count every organism. It is therefore necessary to sample a proportion of the habitat. The sampling process must not be biased.
Outline an unbiased sampling method that can be used to measure the biodiversity of plant
species in grassland. (4mks) (f212 June 14 q3d)
1 (use of) quadrat ; [description of a quadrat / point frame]
[[either a or b for both marking points 2 and 3. Do
not mix a and b marks. If both a and b marks are present
ignore the lower scoring letter]]
2a) random (sampling) ; [bits of paper in a hat / random number generator]
3a) placing measuring tapes (at right angles) / use grid ;[e.g. bottom left hand corner of quadrat placed at
coordinate / two students walk in a straight line from each tape measure]
2b (use of) transect ;
3b (quadrat / point frame) placed at regular intervals ; [systematic sampling]
4 (use of identification) key ;
5 example / detail , of method used to determine
abundance ; [percentage cover / percentage frequency / number of hits with point frame / ACFOR; strategy for dealing with plants half in or out of
quadrat]
6 repeat many times / idea of considering appropriate
number of samples ; [calculate running mean; if number stated then at least 5]
7 sample / AW , at different , seasons / times of year ; [throughout the year]
Scientists try to estimate the total number of species on Earth. Suggest three reasons why such estimates are not likely to be accurate. (F212 June 14 q3e)
1) reason for not having found all species; [e.g. some (named) habitats inaccessible / microscopic species missed / low numbers of individuals / habitat unexplored / some habitats rare / species are
nocturnal]
2) may have become extinct , recently / since recording; [organisms constantly become extinct]
3) evolution is on-going / new species are being formed; [new species are being created]
4) some (species) difficult to distinguish / some species may be reclassified; [e.g. might mistake several species for one; scientists might disagree about whether it is a species or not.]
