Unit 2: Biodiversity Flashcards
(103 cards)
0
Q
Define niche
A
The role occupied by an organism in a particular ecosystem, dependant on the resources it uses
1
Q
Define species
A
Individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics, whose members are able to interbreed freely to produce fertile offspring
2
Q
Define habitat
A
The place where an organism lives
3
Q
Define biodiversity
A
The variety of life
Species richness and species evenness
4
Q
Define ecosystem
A
All the biotic and abiotic factors in a specific area and their interactions
5
Q
What are biotic and abiotic factors?
A
Biotic= living factors eg predators, disease, other species Abiotic= physical/non-living eg light intensity, soil and minerals, soil pH, soil moisture, temperature
6
Q
What is species richness and species evenness?
A
Species richness= the amount of different species
Species evenness= the amount of individuals in each separate species
7
Q
What are the differnt levels of biodiversity?
A
Range of habitats
Differences between species
Genetic variation
8
Q
What is random sampling?
A
Studying a part of a habitat and assuming it obtains a representative set so species found in the whole habitat
9
Q
Why is it important to do random sampling?
A
Avoids bias in results of a survey
10
Q
How many samples should be taken?
A
Dependant on size and time avaliable
Football pitch= 10 1metre squared samples
Wild meadow= 20 1metre squared samples
If comparing 2 or more areas, take the same number of samples!!
11
Q
What is the ACFOR scale?
A
Abundant Common Frequent Obvious Rare
12
Q
How can quadrants be used to measure abundance?
A
Using a grid of strings/point frame you can estimate % cover
13
Q
What are the advantages and disadvantages to using a point frame?
A
:) Gives more accurate % estimate
:) more detailed
:( time consuming
:( as one needle may touch several plants, may give 300-400%
14
Q
How do you use a point frame?
A
Frame holds 10 long needles
Frame lowered into quadrat and number of species touching needle is recorded
Frame with 10 needles used 10 times gives 100 readings=100% coverage
15
Q
What are he two types of transect?
A
Interrupted belt transect-May use quadrats at set intervals from transect
Continuous belt transect-quadrats moved along the line
16
Q
What is the problem with sampling animal habitats? How can this be solved?
A
Animals will move due to disruption to the habitat or hide if they detect presence of larger animals (humans)
Can be solved by trapping and sampling smaller animals whilst larger animals should just be carefully observed
17
Q
What is a sweep net used for?
A
Used for catching small animals like insects
Suitable for low vegetation and water
18
Q
How is a pooter used?
A
Used to collect insects caught in sweep net
Sucked up into observation chamber, prevents insect from crawling/flying away
19
Q
How is a pitfall trap used?
A
Trap is set in soil, hidden to catch any small animals/insects
Trap should have some water/scrunched up paper to stop the animals crawling out
20
Q
How is a till green funnel used?
A
Used to collect small animals from leaf litter
Leaf litter placed underneath a bright light source, small animals driven downwards which fall through a mesh into a jar with preservative in
21
Q
Why do we sample?
A
Human activity affects the environment in many ways-unless we sample, we can’t assess the effect we have
Reduce damage to habitats by estimating effect of planned development on the environment
22
Q
What should you cover in an exam question asking to sample plants/sessile animals?
A
Quadrats
% cover/ACFOR
Random sampling
Map out area and select random coordinates (inc. method to do this)
Measuring tape to measure area
Record results in pre-prepared table
If covering 2 areas-same # and time for samples
Repeat sampling at different times of year
23
Q
Using Simpsons diversity index, what does a high/low value indicate?
A
0=no biodiversity
1=high biodiversity
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What are the advantages to using the Simpsons diversity index?
Don't need to know the species type
| Species diversity is in relation to numbers of different species not just overall numbers
25
What is a plagioclimax?
Where human activity can increase the variety of species found in an area above natural levels
26
Give an example of a plagioclimax
A field with regularly cut grass
- > Dominant species is removed=less competition and more light can get to smaller windflowers
- > More species can do photosynthesis
- > Attracts more insects
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What factors can affect how well a plant survives?
```
Amount of light
pH of soil
Soil mineral ion content
Temperature
Competition
Condition of soil (compact or loose)
```
28
How can trees affect biodiversity?
Tree out competes grass for light and soil minerals
| Tree alters pH and structure of soil
29
How are species sometimes underestimated in sampling?
Some plant species look similar
Some species are easier to spot than others
Do species count if only partially in quadrat?
Not all species present/flower on same day but seeds still in soil
30
What is classification?
Putting things in groups. Natural classification does this by working out how closely related they are
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What is phylogeny?
Study of evolutionary relationships between organisms
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What is taxonomy?
Grouping of organisms into hierarchy of taxa (groups)-the principles behind classification
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Why classify organisms?
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For our convenience
To make studying things more manageable
Make it easier to identify organisms
Help identify species relationships
Help us understand our own evolution
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34
What is the binomial naming system and why do we use it?
Homo Sapiens
-Genus -Species
(Space inbetween, genus has capital, underlined)
This system avoids translation issues as it so he same in all countries
35
What does "King Paul cuts out five gold stars" mean?
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Kingdom
Phylum
Class
Order
Family
Genus
Species
```
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What are the five kingdoms?
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Prokaryotes
Protocists
Fungi
Plants
Animals
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What distinguishes prokaryotes? Give an example
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No nucleus
Loop of naked DNA
No membrane bound organelles
Small ribosomes
Respire in mesosomes
Do heterotrophic and autotrophic nutrition
Eg bacteria
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What distinguishes protocists? Give an example
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Single celled
Mostly free living
Heterotrophic and autotrophic nutrition-some photosynthesise,some ingest prey, some feed using extracellular enzymes, some are parasites
Eukaryotes
Eg algae
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What distinguishes funghi? Give an example
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Eukaryotes
Have a mycelium, consists of hyphae
Walls made of chitin
Multinucleate cytoplasm
Heterotrophic nutrition
Eg ergot fungus
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What distinguishes the plant kingdom?
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Eukaryotes
Multicellular
Cellulose cell wall
Produce multicellular embryos from fertilised eggs
Autotrophic nutrition
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What distinguishes the animal kingdom?
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Eukaryotes
Multicellular
Heterotrophic nutrition
Fertilised eggs develop into a ball of cells=blastula
Usually able to move around
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42
What does an evolutionary tree show?
Where species have common ancestors
| Longer branches are apart, the further apart a species is related
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What are dichotomous keys?
Keys with a series of yes/no (or 2 choice) questions used to identify a species
44
If two species have the same genus, what could this signify?
Common ancestor
Genes in common
Similar features
45
What are the 3 domains?
Archaea
Eu bacteria
Eukaryotae
46
How can cytochrome c be used to show if species are related?
This protein is present in nearly all living organisms, it is vital to respiration. Compare protein sequences:
- similar sequences=species must be related
- different sequences=species not so closely related
- more differences found between sequences, the less closely related species are
47
How can DNA be used to show if species are related?
DNA found in all living organisms and provides genetic code
| -> we can compare DNA sequences and identify how closely related different species are
48
How is bacteria fundamentally different to archaea and eukaryotae?
Different cell membrane structure
Flagella have different internal structure
Different enzymes for building DNA (RNA polymerase)
No protein bound to genetic material
Different mechanisms for DNA replication and building RNA
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How are archaea and eukaryotae similar?
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Similar enzymes (RNA polymerase) for building RNA
Similar mechanisms for DNA replication and building RNA
Production of some proteins that bind to their DNA
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50
What is discontinuous variation?
Characteristics with just a few discrete categories
Eg blood group, sex, presence or absence of bacterial flagella
Characteristics: have distinct categories, groups don't overlap, are usually controlled by only one gene, aren't affected by the environment
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What is continuous variation?
Characteristic has a continuous range of values- 2 extremes and a full intermediate range inbetween
Eg height, length of leaves on an oak tree, length of stalk of toadstools
Characteristics: have no distinct categories, tend to be quantitive with overlaps between categories, controlled by a number of genes (polygenic), are significantly affected by environment
52
Why are identical twins not identical in terms of their DNA?
DNA replication and cell division may introduce changes
| Slight environmental differences in the womb or after birth can result in physical differences
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What is a dichotomous key?
A key with a series of yes/no (or 2 choice) questions used to identify a species
54
How do genes cause variation?
Inherited genes provide info used to define characteristics-results in unique combinations of alleles
We can share alleles/genes with members of our own species but there is never a complete match
55
How does environment cause variation?
Eg overrating can lead to obesity
Exposure to sunlight will cause skin to darken
Environment can affect direction/amount of growth in plants depending on environment
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What is an adaptation?
Any variation that helps an organism to survive its environment
57
Give an example of how behavioural adaptations can aid survival
Earthworms will withdraw when touched
| -they don't have eyes so this helps them avoid being eaten by birds
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Give an example of how physiological adaptations can aid survival
A kind of yeast can respire aerobic ally or anaerobically to obtain energy
-adaptations produce the right enzymes to correctly respire sugars
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Give an example of how anatomical adaptations can aid survival
Bacterial flagella enable independent movement
60
How do adaptations cause evolution?
Adaptations form from environmental selection pressures->mutations
Those better adapted to the environment will survive to reproduce
Adaptation passed onto offspring
Adaptation spreads throughout species
61
How are xerophytic plants behaviour adapted to survive?
Stomata close in low water availability
Leaves roll/fold if water shortage-traps air and lowers WVP
Some stomata will open on leaves amusing them to wilt-decreased SA for water loss
62
How are xerophytic plants physiologically adapted to survive?
The saguaro cactus stem has an accordion-fold structure
- the folds tighten into ridges during dry periods
- when water is available and is taken up, cells expand to take up more water
63
How are xerophytic plants adapted anatomically to survive?
Shallow roots covering large SA
Long roots reach deeper
Fleshy stem/leaves to store water
Leaves might have: smaller SA, have hick waxy cuticle, hairs, sunken stomata
64
Why do we conserve a species?
Aesthetic reasons
Moral-we have caused their endangerment
Medical-undiscovered treatments/drugs
Economic-future food source or tourism
Environmental-loss of one species could trigger others (food chains), invasive species can damage food chains eg grey squirrel
65
What is a monoculture?
An extreme loss of biodiversity to the point at which only one species can survive in an area
66
What is extinction?
When a species ceases to exist permanently
67
What needs to be considered in an Environmental impact survey?
1) size of the area
2) potential damage to the area
3) level of biodiversity-are species endangered or common?
- >high=area can cope with change
- >low=area more vulnerable to change
4) How can plans be altered to minimise impact?
5) Alternative site?
68
What are the problems with carrying out an EIA?
Doing the survey itself causes some damage/disturbance to the environment
Could miss a species if not carried out extensively
No central organisation
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Why is genetic diversity vital?
Makes species evolution possible
| -without diversity, species can't adapt
70
How are humans limiting genetic variation?
Clearing natural vegetation=smaller natural habitats+smaller populations
-> smaller gene pool=less genetic variation
Monocultures and selective breeding
-loss of genetic variation and genetic erosion
71
How will climate change affect species with a. Low genetic variation?
Unable to evolve to suit their environment
- as climate changes, only alternative is to migrate to more suitable climate
- migration can be obstructed by human developments, large bodies of water, humans, agricultural land
72
How will climate change affect agriculture?
More CO2 affecting photosynthesis
Higher temperatures means increased growth rate
Longer growing season
More evaporation of water=greater precipitation
Loss of land due to rising sea levels and increased soil salinity
73
What could climate change do to disease?
Higher temperatures give pests more time to reproduce-can start infecting crops earlier
=lower yield and less food for humans
Could cause human diseases to migrate-tropical diseases could migrate to Europe eg malaria
74
Why should we conserve plant habitats with undiscovered plants?
Could have alternative medical treatments
| Could be used to improve crop resistance using selection and breeding
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What is in-situ conservation?
Protecting a species in its natural habitat
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What is ex-situ conservation?
Removing a species from its natural habitat to protect it
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What is the Noah's ark approach?
Captive breeding can be used to preserve a species that is desperately low on numbers
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What are the problems with captivity?
Too large/too specific a habitat needed
Expensive
Some species have complicated social interactions
Species may be dependant on another
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What are the problems with captive breeding?
Some won't breed
A small gene pool can lead to inbreeding-could result in appearance of harmful genetic recessive diseases
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How can zoos limit inbreeding with captive breeding?
Stud books-record of animals that've bred together
Try and work with other zoos
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What are the problems with releasing captive animals?
Lack hunting skills
Unable to recognise predators
Lack of immunity to wild diseases
Stress can lead to injuries
Animal might not be accepted by wild packs/herds
82
What are the problems with seed storage?
Some seeds (eg with high water content) can't be stored
Some plants produce asexually=no seeds
Sample may not hold representative selection of genetic diversity
Research from a small sample which not match with entire species
Asexually bred plants will be identical=less diversity
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What do seed banks do to get fresh seeds from stored ones?
They will germinate and grow seeds into plants so that new seeds can be acquired
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How can we preserve genetic material?
Sperm freezing/storing eggs
Carry out research on species to ensure preservation techniques will work (reproductive physiology varies between species)
85
How can we prevent experimenting on endangered species?
Carry out research on similar, domestic species
86
What 4 observations did Darwin make in his visits to the Galápagos Islands?
Offspring generally appear similar to parents
No two individuals are identical
Organisms have the ability to produce large numbers of offspring
Populations tend to stay stable in size
87
What deductions did Darwin make from his observations on the Galápagos Islands?
There is competition for survival
Individuals with characteristics that best apart them to survive will reproduce
Inherited characteristics are passed onto their offspring
88
What is the perfect answer for a typical natural selection question in your exam WHICH IS EXTREMELY FUCKING CLOSE??
Mutation occurs (random change in DNA)
Selection pressure decides which are best adapted and give a specific selection pressure
Best adapted=survive and reproduce
Pass on genes to offspring
This process is called NATURAL SELECTION (BITCH!)
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What is speciation?
The formation of a new species from a pre-existing one
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What is a species?
A group of interbreeding populations that are reproductively isolated
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Give an example of a selection pressure
Availability of food
Predators
Disease
Physical/chemical factors
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What is allopatric speciation?
If a species is separated by a geographical events (eg a river, earthquake, volcano) SPECIATION will occur
Even if the sprayed species are put back together they will be so different they would be unable to breed
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What is sympatric speciation?
A reproductive barrier may arise within a population (Eg biochemical changes in free ones/hormones) making them no longer compatible
Speciation occurs as a result
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What 3 things did Darwin use as his original evidence for natural selection?
Fossils- showed species dying out and new species arising, with similarities between both
Brachiopods-change in form over time, with different species in different ages
Armadillos and glyptodonts-A were similar to G but had adapted to environment
A=15cm whilst G=1m+
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What problems are there with using fossils as evidence for natural selection?
Often gaps in fossil record
- fossils only remains of hard parts
- need right conditions for fossils to form
- fossils might get damaged
96
How do we use biological molecules for evidence of natural selection?
Living things are shown to be more similar if they have similar biological molecules eg cytochrome c
Long time=evolved biological molecules will differ more
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Higher organisms (evolved later on) have extra subunits of DNA polymerase
Lower organisms have slightly different amino acid chains in cytochrome c
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How can molecular evidence be used as evidence for natural selection?
DNA can be extracted form bones-can study degrees of similarity between bones base sequences
Eg gene for eye development in vertebrae similar to gene for wing development of fruit fly
98
Where does evolution occur today?
- wherever there is a selection pressure
| - is more obvious in organisms with a short life cycle
99
How are some Mosquitos resistant to DDT?
Resistance is due to a modified receptor protein on the cell surface membrane
Or
They have an enzyme that can break the poison down
100
What does MRSA stand for?
Methicillin resistant Staphyloccus aureus
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How are we preventing further resistant strains of MRSA developing?
Multiple antibiotics to reduce chances of bacteria surviving
Doctors should ensure patients finish antibiotic courses even if they feel better
Not prescribing antibiotics all the time
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What is the 'arms race'?
Medical researchers are struggling to develop new and effective drugs but bacteria populations are rapidly becoming resistant to them
