Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OCR A LEVEL BIOLOGY > M4, C11 Biodiversity > Flashcards

M4, C11 Biodiversity Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

define biodiversity

A

a measure of the variety of different organisms in a specific area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the measures of sampling

A

number of organisms
distribution of organisms
measurable characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the 3 non random techniques of sampling

A

opportunistic - sample that is most conveniently available
stratified - put organisms into subgroups and random sample taken from each
systematic - identify different areas then sample separately

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the difference between line and belt transects

A

line transect is one line with quadrats placed at intervals whereas belt transects are two parallel lines and you take an area between the two line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the similarities between line and belt transects

A

see the distribution of organisms over a period time

quadrats placed at regular intervals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are point quadrats

A

frame containing horizontal bar
at set intervals along the bar, long pins can be pushed into the ground
each species the pin touches is recorded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are frame quadrats

A

square frame divided into a grid of equal sections

the type and number of species within each section is recorded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why is biodiversity important

A

maintains a balanced ecosystem
needed for food, oxygen, materials
every species relies on one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are the different levels of biodiversity

A

habitat - number of different habitats in an area
species - richness and evenness
genetic - the variety of genes that makes up a species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the two components of species biodiversity

A

species richness - number of different species in an area

species evenness - comparison of the numbers of individuals of each species living in a community

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is genetic biodiversity

A

variety of genes that makes up a species

eg. humans have around 25,000 genes but some plants have 400,000

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what type of sampling is line and belt transects

A

systematic sampling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why is sampling not always reliable

A

could be bias because you chose the area with the most flowers or it looks interesting
by chance the area you picked might not be representative of the whole population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are some ways to sample animals

A

pooter - catches small insects by sucking on a tube which brings smaller insects into a container
sweep nets - insects in long grass
pitfall traps - small crawling invertebrates captured in a hole in the ground which has a roof so it doesn’t fill with rainwater
tree beating - invertebrates living in trees captured in a white cloth a the bottom of the tree that is shaken or beaten
kick sampling - organisms in a river, substrate is disturbed and a net captures organisms which move into the flowing water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the 3 ways of using quadrats

A

density of plants - used for large plants so you count the actual number in a quadrat

frequency - used for species that are hard to count, like grass so you count how many squares the species is in to get a percentage

percentage cover - estimate by eye - quick and gives an estimate of abundance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

define species richness

A

measure of the number of different species living in a specific area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

define species evenness

A

how close in numbers the populations of each species in an environment are

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how do you estimate animal population size

A

capture-mark-release-recapture technique

the greater the number of marked individuals recaptured, the smaller the population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what are abiotic factors

A

non-living conditions in a habitat
they have a direct effect on organisms
eg. light and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

for each abiotic factor, give the sensor used and the unit

a) wind speed
b) light intensity
c) relative humidity
d) pH
e) temperature
f) oxygen content in water

A

wind speed - anemometer, ms^-1
light intensity - light meter, lx
relative humidity - humidity sensor, mgdm^-3
pH - pH probe, pH
temp - temperature probe, degrees C
O2 content in water - dissolved oxygen probe, mgdm^-3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the advantages of using sensors when measuring abiotic factors

A

rapid changes can be detected
human error reduced
high degree of precision can be achieved
data can be stored and tracked on a computer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what area would be considered less diverse

A

an area that is dominated by only one or two species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is simpson’s diversity index

what’s the calculation

A

calculates biodiversity

D = 1 - E(n/N)^2

D = simpsons diversity index
n = total number of organisms in 1 species
N = total number of all organisms
E = the sum of (couldn't put in correct symbol)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what do the results of the simpsons diversity index show

A 
0 = no diversity
1 = infinite diversity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how does the number of successful species differ in a low biodiversity and a high biodiversity

A

there are relatively few successful species in a low biodiversity
there are large number of successful species in a high biodiversity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

how does the nature of the environment differ in a low or high biodiversity

A

low biodiversity - extreme conditions with relatively few ecological niches
high biodiversity - not stressful with more ecological niches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how does the adaptation of species differ in a low and high biodiversity

A

low biodiversity - relatively few species often with very specific adaptations
high biodiversity - many species with few specific adaptations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how do the type of food webs differ in a low and high biodiversity

A

low - simple food webs

high - complex food webs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how does the effect of a change in environment differ between low and high biodiversity

A

low - major effects on ecosystem

high - often a relatively small effect

30
Q

what are alleles

what do more alleles mean

A

different versions of genes

the more alleles present in a population means the more biodiverse it is

31
Q

why is genetic biodiversity useful

give an example

A

useful for the survival of the species
the more diverse means the higher the likelihood that some members will be able to survive new selection pressures
eg. the peppered moth

32
Q

what factors increase genetic biodiversity

A

mutations - new alleles caused

interbreeding between populations/ gene flow - new alleles from other populations

33
Q

what factors decrease genetic biodiversity

A 
selective breeding
captive breeding programmes
rare breeds
artificial cloning
natural selection
genetic bottlenecks
founder effect
genetic drift
34
Q

how do you quantify genetic biodiversity

A

measure polymorphism
a polymorphic gene has more than one allele
a monomorphic gene has a single allele
the higher the proportion of polymorphic gene loci, the higher the genetic biodiversity of a population

35
Q

what is locus or loci

A

the position of a gene on the chromosome

36
Q

there are 10 loci in total and 4 were polymorphic

what is the proportion of polymorphic gene loci

A

4/10 X 100

= 40%

37
Q

how do you calculate the proportion of polymorphic gene loci

A

Number of polymorphic genes / total number of loci

38
Q

what are gel electrophoresis
what does it mean if you have a smaller fragment
if the loci has one band what does it mean

A

Restriction Enzymes cut DNA into smaller pieces
The pieces are placed into a gel
Positive and Negative electrodes are placed on either end of the gel
The negatively charged DNA travels toward the positive electrode
The smaller the fragment, the further it travels across the gel
A banding pattern is produced, which can be used to compare different loci between individuals
If a loci has one band it is monomorphic, if it has more it is polymorphic

39
Q

why has the human population increased so quickly

A

improvements in medicine, hygiene, housing and infrastructure
so people live longer

40
Q

what are the affects of an increasing population

A

more space is needed for housing, industry and farming
humans are disrupting the ecology of many areas
more deforestation, agriculture and climate change

41
Q

how could deforestation naturally occur

A

forest fires caused by lightning or extreme heat and dry weather

acid rain also but that is caused by humans through pollutants

42
Q

how does deforestation affect biodiversity in animals

A

destroys habitats
destroys food sources for animals
so number of animals decrease

animals could also be forced to migrate to other areas so biodiversity increases in a certain area

43
Q

how does deforestation affect biodiversity in plants

A

directly reduces the number of trees
if only one tree is destroyed, species diversity is reduced
eg. rosewood is often cut down but this reduces useable trees

44
Q

how does agriculture reduce biodiversity in animals

A

deforestation and removal of hedgerows creates land to cultivate but this reduces habitats for animals and destroys their food source
pesticides kills insects or animals that eat the crops but this directly kills a species and destroys a food source
herbicides also directly destroy the food source of weeds
monoculture - only one crop is grown and lots of species can’t live amongst only one plant

45
Q

how does agriculture reduce biodiversity in plants

A

deforestation to get land directly removes trees
removal of hedgerows destroys plant species
herbicides kills weeds - plant diversity directly reduces
monoculture - only one plant grown

46
Q

what were some key findings in the 2007 IPCC about climate change

A

The warming trend over the past 50 yrs is twice of that of the last 100 yrs
Water vapour in the atmosphere has increased
The ocean has absorbed 80% more heat causing the sea level to rise
The arctic temps have doubled in the last 100 years
Long-term upward trend of precipitation

47
Q

why do some people not think climate change is caused by humans

A

the earth’s climate has shown fluctuations throughout history

48
Q

how does co2 lead to climate change

A

traps thermal energy in the atmosphere

49
Q

how does global warming/ climate change affect biodiversity

A

melting of ice caps leads to extinction of species. animals have to migrate to find habitats so more diversity in the north
rising sea levels flood low-lying land which destroys species. saltwater also flows further up rivers reducing fresh water for plants and animals
Higher temps and less rainfall mean species can’t survive meaning xerophytes become more dominant. this means food sources are lost
insect life cycles will change as they do things according to climate, which means some plants could be left out in pollination
tropical diseases could spread more easily killing off species

50
Q

what are the aesthetic reasons to maintain biodiversity

A

presence of different plants and animals enriches our lives
natural world provides inspiration for musicians and writers
studies show patients recover quicker from stress or injury in a natural environment around plants

51
Q

what are the economic reasons to maintain biodiversity - 8 reasons

A
  • deforestation can cause soil erosion meaning we can’t grow crops so rely on other nations
  • if resources are removed then industry could collapse
  • biodiversity loss means that species can become extinct before they are discovered which could have been important for medicines
  • monoculture leads to soil depletion which reduces soil nutrients and makes ecosystem more fragile so farmers will rely on expensive fertilisers to maintain productivity
  • biodiversity provides protection against extreme weather and diseases so if we don’t maintain it then disease could wipe out crops eg. Irish potato famine
  • areas with biodiversity attract tourists
  • greater the biodiversity, the higher the potential to make products in the future
  • more species means more cross breeding in plants which could lead to more resources
52
Q

what are the ecological reasons to maintain biodiversity

A
  • if you remove a species, a food source could be lost, food chains are destroyed
  • eg. if bee numbers lower, less plants are pollinated meaning biodiversity decreases
  • keystone species are essential for ecosystems because they have disproportionately large effect on their environment relative to their abundance
  • maintain genetic resources so we can get food, drink, clothing, drugs and fuels
53
Q

explain how sea stars, alligators and prairie dogs are keystone species

A

sea stars - they limit the population of urchins and mussels by eating them. it means there isn’t a domination of one species in the ecosystem so biodiversity remains high

alligators - make burrows for nesting. when they abandon it, it fills with fresh water which other animals use for breeding and drinking

prairie dogs - extensive tunnelling system which other animals can use. they are also a food source. soil remains healthy from the tunnelling which spreads nutrients which keeps plant life biodiverse

54
Q

define conservation

A

the preservation and careful management of the environment and of natural resources

species and genetic diversity can be safeguarded

55
Q

what are the two main categories of conservation and define them

A

in situ conservation - within the natural habitat

ex situ conservation - out of the natural habitat

56
Q

in conservation how are species classified

A

extinct
extinct in the wild
endangered
vulnerable

57
Q

what is sustainable development

A

economic development that meets the needs of people today, without limiting the ability of future generations to meet their needs

58
Q

in wildlife reserves, what are active management techniques

A
  • controlled grazing
  • restricting human access
  • controlling poaching eg. removing rhino horns
  • feeding animals
  • reintroduction of species
  • culling or removing invasive species
  • halting succession (so habitats don’t turn back to woodland or become overgrown)
59
Q

define succession

A

a natural process in which early colonising species are replaced overtime until a stable mature population is achieved

60
Q

what is the purpose of marine conservation zones

A

to create areas of refuge within which populations can build up and repopulate adjacent areas

they prevent fishermen visiting because non-sustainable fishing methods can be devastating

61
Q

what are the advantages of in situ conservation

A 
species and habitats are conserved
species have resources its adapted to
species continue to evolve
more space
bigger breeding population
cheaper than ex situ
62
Q

what are the disadvantages of in situ conservation

A

difficult to control illegal exploitation eg. poaching :(

difficult to control environment and predators

63
Q

how do botanical gardens maintain biodiversity

what are their limitations

A

plants are managed and provided with the correct nutrients, water and pests are removed

90% of plants aren’t conserved and these could be potential sources of genes which are resistant to disease or pests

64
Q

what is a seed bank

what is its limitation

A

seeds are dried and stored at temps of -20 degrees to maintain their viability

provides a back up against the extinction of plants

some seeds die when they’re dried which is mainly tropical rainforest trees

65
Q

what are captive breeding programmes

A

produce offspring of species in a human-controlld environment
often run and managed in zoos or aquatic centres

their aim is to create a stable, healthy population of a species and gradually introduce the species into the wild

maintaining genetic diversity is difficult

66
Q

why can’t some organisms born in captivity be released in the wild? (4)

A
  • they might have lost resistance to local diseases
  • some of their behaviour is natural but some they are taught in the wild eg. they can’t learn to hunt as well in captivity
  • the genetic make up of captive animals can become different from the original population meaning they can’t interbreed
  • there might not be a big enough habitat for them to fit into, if there are already too many animals in one place it will cause tension and stress
67
Q

what is the international union for the conservation of nature (IUCN)

A

it secures agreements between nations
once a year they publish a list of the conservation status of species which countries can then work together for

they also established CITES which regulates trade of plant and animal specimens

68
Q

what is the rio convention

A

1992 - meeting between 172 nations
aka the earth summit
Agreements made were:
-countries had to develop national strategies for sustainable development
-take steps to stabilise greenhouse gas concentrations
-prevent the transformation of fertile land into desert and reduce effects of drought

69
Q

what is the countryside stewardship scheme

A

offered government payments to farmers and land managers to enhance and conserve English landscape
aims were:
-sustain beauty and diversity
-improve, extend and create wildlife habitats
-restore neglected land
improve opportunities for countryside enjoyments

now been replaced by Environmental Stewardship Scheme

70
Q

What are the pros of ex situ conservation

A

Controlled environment (predation easily managed)

Reintroduction of species

71
Q

What are the disadvantages of ex situ conservation

A

Only small number of organisms cared for
Difficult and expensive to create right environment
Difficult in adopting to new location/environment
Captivity breeding isn’t very successful

OCR A LEVEL BIOLOGY (23 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions