Unit 3 - sustainability & interdependence Flashcards
(160 cards)
1
Q
what are the three measurable components of biodiversity
A
- genetic diversity
- species diversity
- ecosystem diversity
2
Q
what is genetic diversity a measure of
A
measure of genetic differences within and between individuals, populations and species
3
Q
what is genetic diversity and what does it mean
A
the number and frequency of all the alleles within a population. if one species dies out then the species may have lost some of its genetic diversity, and this may limit its ability to adapt to changing conditions
4
Q
what is species diversity
A
the number of different species in an ecosystem (the species richness) and the proportion of each species in the ecosystem (the relative abundance)
5
Q
which one has a lower species diversity;
1. a community with a dominant species
2. a community with the same species
richness but no particularly dominant
species
A
- a community with a dominant species
6
Q
what is ecosystem diversity
A
the number of distinct ecosystems within a defined area
7
Q
what has lead to the overexploitation of some species
A
a growing population
8
Q
give an example of overexploitation
A
overfishing fish to the point where it is no longer sustainable
9
Q
what happens during overexploitation
A
populations can be reduced to a low level but may still recover
10
Q
what is a population bottleneck (or genetic bottleneck)
A
an evolutionary event in which a significant percentage of a population or species is killed or otherwise prevented from reproducing
11
Q
what is the bottleneck effect and what can this result in
A
when small populations may lose the genetic variation necessary to enable evolutionary responses to environmental change. in small populations, this loss of genetic diversity can be critical for many species, as inbreeding can result in poor reproductive rates
12
Q
what is habitat fragmentation and what causes it
A
the breakup of an organisms preferred habitat can be caused by human activities
13
Q
give four examples of human activities which lead to habitat fragmentation
A
- clearing forests for agriculture
- clearing forests/agricultural land for housing/industry
- building dams and flooding surrounding land
- building roads
14
Q
what does habitat fragmentation lead to and what may this result in
A
degradation of the edges of habitat fragments results in increased competition between species as the fragment becomes smaller. may result in a decrease in biodiversity as species may be lost. (increasing fragmentation, decreasing species diversity)
15
Q
what is a possible way of reducing the impact of widespread habitat fragmentation
A
by linking isolated fragments with habitat corridors
16
Q
what do habitat corridors allow and what may they lead to
A
movement of animals between fragments, increasing access to food and choice of mate. may lead to recolonisation of small fragments after local extinctions
17
Q
what is an introduced species
A
a species that humans have moved, either intentionally or accidentally, to new geographical locations
18
Q
what are naturalised species
A
those that become established within wild communities, they will be able to flourish in the new environment without human input
19
Q
what are invasive species
A
naturalised species that spread rapidly and eliminate native species, therefore reducing species diversity
20
Q
what things may invasive species be free of in their new habitat
A
the predators, pathogens, parasites and competitors that limit their population in their natural habitat
21
Q
what may invasive species do to naturalised ones (3 things)
A
prey on them, outcompete them for resources or hybridise with them
22
Q
what leads to the demand for increased food production (2 things)
A
increase in the human population and concern for food security
23
Q
define food security
A
the ability of human populations to access food of sufficient quality and quantity
24
Q
what three factors affect food security
A
- access
- quantity
- quality
25
name three crop species and give examples of them
1. cereals e.g. maize, rice
2. root crops e.g. potato, cassava
3. legumes e.g. soya bean
26
what must food production be
sustainable and not degrade the natural resources on which agriculture depends
27
how can agriculture reduce limiting factors to improve yields
by adding minerals (fertilised) or water (irrigation systems) to remove factors which may be limiting plant growth
28
how can agriculture protect crops to improve yields and what do they need protecting from
protection from pests (e.g. insects), diseases, and competition (from weeds) by using pesticides, fungicides and herbicides
29
what can be developed in agriculture to improve yields
pest resistant crop plants
30
what can existing strains of crops be replaced with in agriculture to improve yields
replace existing strains of crops with a higher yielding cultivar (cultured variety)
31
why does something need to be done to improve agriculture yields
the area suitable for growing crops is limited
32
why do livestock produce less food per unit area than crop plants and what does this result in
due to loss of energy between trophic levels. therefore arable lane planted with crops produces far more food than the same land planted with grass to feed livestock
33
when is it more efficient to use land for livestock
not all land can be planted with crops and in this case it is more efficient to use land for livestock
34
what are the three fates of light
1. absorbed by the pigments in the leaf
2. reflected off the surface
3. transmitted through the leaf
35
what do leaves contain (chlorophyll is one)
several coloured pigments
36
what do different pigments do in a leaf
different pigments absorb different wavelengths (colours) of light
37
what is shown on the action spectrum graph
the rate of photosynthesis at different wavelengths of light
38
what is the absorption spectrum produced to represent
the ability of each pigment to absorb different wavelengths of light
39
how can we tell (from the action and absorption spectra) that chlorophyll is the main pigment involved in photosynthesis
if an action spectrum and absorption spectrum for chlorophyll are on the same graph. they both have peaks at blue and orange/red wavelengths.
40
what does the leaf contain as well as chlorophyll
pigments known as cartenoids
41
what do cartenoids do
extend the range of wavelengths absorbed in photosynthesis AND passes energy onto chlorophyll
42
what do carotenoids do
extend the range of wavelengths absorbed in photosynthesis
43
what are cartenoids known as and why
accessory pigments as they pass the energy they capture onto chlorophyll
44
what is stage one of photosynthesis called
light reactions
45
what happens during stage one of photosynthesis
light energy is absorbed by photosynthetic pigments (chlorophyll and accessory pigments) and is used for generation of ATP and photolysis (splitting of water)
46
what happens (during photolysis) and when light energy is absorbed by the pigments in the chloroplast
electrons in the pigment become excited and are raised to a higher energy state
47
what happens to the electrons after they are raised to a higher energy state in photolysis
the electrons are then transferred along an electron transport chain, releasing energy
48
what is the energy generated by the transferring of electrons along an electron transport chain used to generate and what is it also used for
ATP by ATP synthase. also used for photolysis, in which water is split into oxygen which is evolved (released), and hydrogen, which is transferred to the coenzyme (hydrogen acceptor) NADP to make NADPH
49
what is a by product of the light reactions stage of photosynthesis
oxygen
50
what is photolysis
(the transfer of…)
the transfer of energy in the light reactions stage of photosynthesis
51
what is the second stage of photosynthesis called
carbon fixation (calvin cycle)
52
what is the carbon fixation stage of photosynthesis and what is made from it
it’s a series of enzyme controlled chemical reactions where glucose is made
53
what is the first stage of carbon fixation
carbon dioxide enters the cycle and becomes attached to RuBP (ribulose-biphosphate). this reaction is controlled by the enzyme RuBisCO (ribulose biphosphate carboxylase/oxygenase)
54
what happens after CO2 enters the cycle in carbon fixation
the carbon dioxide and RuBP combine to make 3-phosphoglycerate (3PG)
55
what happens to the 3PG after it is made in carbon fixation (step three)
the 3PG then joins with the hydrogen from NADPH and is phosphorylaysed by the addition of phosphate (Pi) from ATP which supplies the energy
56
what does the process of the phosphorylation of the 3PG produce (step 4 of carbon fixation)
this process produces glyceraldehyde-3-phosphate (G3P)
57
what is the G3P used for in the last stage of carbon fixation
some G3P is then used to regenerate RuBP (to continue the process). the remainder is used to synthesise glucose
58
what is the sugar formed during photosynthesis then used for
glucose:
for respiration (respiratory substrate), starch (storage carbohydrate), cellulose (structural carbohydrate e.g. cell wall) and biosynthesis pathways (fats and oils, proteins and nucleic acids (DNA, RNA))
59
what does plant and animal breeding improve and why
to improve characteristics to help support sustainable food production
60
what four characteristics do breeders develop crops and animals with
1. higher food yields
2. higher nutrition values
3. disease resistance
4. the ability to thrive in particular environmental conditions
61
what is a plant field trial
a type of investigation carried out in a range of environments
62
what three things can plant field trials investigate
1. compare the performance of different plant cultivars (e.g. species A vs. species B) under the same set of environmental conditions
2. find out the effect of different environmental conditions (treatments) on a new cultivar of crop plant
3. evaluate GM crops (conventional v GM crop)
63
what factors need to be considered when designing a plant field trial
1. selection of treatments to be used
2. number of replicates to be included
3. randomisation of treatments
64
what is the reason for randomisation of treatments during a plant field trial
to eliminate bias when measuring treatment effects
65
why are the number of replicates important during a plant field trial
to take into account the variability within a sample (experimental error)
66
why is the selection of treatments important during a plant field trial
to ensure fair/valid comparisons
67
What does inbreeding involve
The fusion of gametes from close relatives
68
What organisms is inbreeding naturally occurring in
Self pollinating plants e.g. peas, wheat and rice
69
What does inbreeding ensure
Members of the each generation of a selectively bred strain receive alleles for the desired characteristic
70
What two things can inbreeding lead to
1. Loss of heterozygosity
2. Inbreeding depression
71
What does loss of heterozygosity mean
The population begins to breed true to the desired type
72
What is inbreeding depression due to
The accumulation of homozygous recessive deleterious (harmful) alleles
73
What does inbreeding depression appear as and what does this mean for the individuals
A decline in vigour, size, fertility and yield of the plant or animal. This means these individuals do less well at surviving to reproduce
74
Why are some plants less susceptible to inbreeding depression
Due to the elimination of deleterious alleles by natural selection
75
Why is inbreeding rarely carried out indefinitely
Due to the problems associated with inbreeding depression
76
How can new alleles be introduced to plant and animal lines
By crossing a cultivar or breed with an individual with a different desired genotype
77
What can cross breeding produce
A new crossbred population that have improved characteristics
78
What happens after new alleles are introduced to plant and animal lines
The two parent breeds can be maintained to produce more crossbred animals showing the improved characteristic
79
How are F1 hybrids produced (plants)
By the crossing (hybridisation) of two different inbred homozygous cultivars
80
What does crossbreeding in plants create
A relatively uniform heterozygous crop
81
What do F1 hybrids display
Increased vigour and yield
82
What may increased vigour mean
Increased growth rate and disease resistance
83
What may happen if desirable F1 hybrids are allowed to interbreed with one another
The F2 generation can be too genetically diverse and many will lack the improved characteristics seen in F1
84
What two genetic technologies can plants and animals be enhanced by
1. Genetic sequencing
2. Genetic transformation
85
What can genome sequencing techniques be used to identify
Organisms that possess particular alleles for a desired characteristic. This organism can then be selected for use in a breeding programme
86
What can breeding programmes involve
Crop plants that have been genetically modified using recombinant DNA technology
87
How are genetically modified plants created with improved characteristics
Single genes for desirable characteristics can be inserted into the genomes of crop plants
88
What three ways can crop productivity be reduced
1. Weeds
2. Pests
3. Diseases
89
What three things have to be tightly controlled to ensure the greatest yield of the crop
1. Weeds
2. Pests
3. Fungal infections
90
What do weeds compete with crop plants for
Resources
91
What two main groups can weeds be categorised into
1. Perennial weeds
2. Annual weeds
92
What are the four properties of annual weeds
1. Produce vast numbers of seeds
2. Grow very quickly
3. Seeds are viable for long periods of time
4. Short life cycle
93
What are the three properties of perennial weeds
1. Reproduce vegetatively (asexually)
2. Already established in the habitat
3. Have storage organs to provide food when conditions are poor
94
What organisms are most of the pests of crop plants and give examples
Invertebrate animals like insects, nematode worms and molluscs
95
What is the effect of invertebrate pests on plants
They destroy the leaves which reduces the plants ability to carry out photosynthesis, and therefore their ability to produce sugar. This causes a reduction in vigour and yield of the crop
96
What are plant diseases caused by and what three things can this either be
Pathogens. Either:
1. Bacteria
2. Fungi
3. Viruses
97
What are plant diseases often carried by
Invertebrate vectors (carriers)
98
What two ways can weeds, pests and diseases be controlled by
1. Cultural means
2. Chemical means
99
What are the three cultural methods of crop protection
1. Ploughing
2. Weeding
3. Crop rotation
100
What does ploughing do
Removes and kills weeds in deep soil
101
What does weeding do
Decreases competition as weeds are removed (weeds removed from edges to prevent pathogens increasing)
102
What does crop rotation do
Crops moved from different fields. The pathogens in the soil cannot spread to the second crop. This adds nutrients to the soil
103
What are pesticides and what do they do
Chemicals which are applied to crop plants to protect them from damage
104
What are the five pesticides and their roles
1. Herbicides to kill weeds
2. Fungicides to kill fungal diseases
3. Insecticides to kill insects
4. Molluscicides to kill mollusc pests
5. Nematocides to kill nematode pests
105
What two categories can pesticides fall under
1. Systemic
2. Selective
106
How do systemic herbicides kill weeds
They are absorbed into the plants transport system and quickly spread through the vascular system of the plant. This has a lethal effect on the leaves and the roots of the plant so avoids regrowth of the weed
107
How do systemic insecticides, molluscicides and nematocides kill pests feeding on plants
They spread through the vascular system of plants and kill pests feeding on them
108
What do selective herbicides do
Mimic the action of plant growth hormones
109
How do selective herbicides work
By being absorbes through the leaves which speeds up the metabolism of plants to the extent that they use up their food reserves and die
110
What plant species do selective herbicides have a greater effect on
Broad leaved weeds
111
When will farmers apply fungicide to their crops
Based on disease forecasts (predictions)
112
What sort of method is using fungicide
Preventative, more effective than treating crops which are already diseased
113
What are the three issues associated with using pesticides
1. Toxicity to non-target species
2. Persistence in the environment, bioaccumulation or biomagnification in food chains
3. Producing resistant populations of pests
114
Define bioaccumulation
A build up of chemical in an organism
115
Define biomagnification
An increase in the concentration of a chemical moving between trophies levels
116
What is biological control and give three examples
The control of a pest population through either the introduction of one of its natural ‘enemies’
Either:
1. A predator
2. A parasite
3. A pathogen of the pest
117
What three things was the wellbeing of animals traditionally judged on
Solely their physical health indicated by their ability to:
1. Grow
2. Reproduce and raise offspring
3. Resist disease
118
What is it now agreed that an important part of an animal’s welfare is
The provision of opportunities for it to express its normal, natural behaviour patterns
119
What are two negatives of free range farming
1. More land needed
2. More labour intensive
120
What are two positives of free range farming
1. Product sold at a higher price
2. Animals have a better quality of life
121
What is a negative and a positive of intensive farming
Negative:
Poorer animal welfare
Positive:
Higher output (high profit:low cost)
122
What can indicate poor animal welfare
When animals show behaviour patterns in confinement that differ from those in a natural environment
123
What is stereotypy and when is it often seen
A behaviour pattern where an animal makes repetitive movements. This is often shown by animals housed in bare and/or confined enclosures
124
What is misdirected behaviour and when is it common
When normal behaviour is directed inappropriately towards the animal itself, another animal or its surroundings. Common in animals that are in isolation
125
Give two examples of misdirected behaviour
1. Excessively licking, plucking or chewing limbs
2. Overgrooming
126
How can misdirected behaviour be reduced
By enriching the animals environment. One way to do this is by providing the animals with companions of their own in a stimulating environment, with sounds, scents and objects similar to those in a natural habitat
127
What two things can poor welfare be responsible for
1. The failure in sexual behaviour resulting in low reproductive success
2. The failure of parental behaviour where animals may produce young, but reject them, and fail to act as effective parents
128
What are five indicators of poor animal welfare
1. Stereotypy
2. Misdirected behaviour
3. Failure in sexual behaviour
4. Failure in parenting behaviour
5. Altered levels of activity (very high-hysteria/low-apathy)
129
What is symbiosis
The close relationship between two different species. Coevolution occurs and the species become closely adapted to each other
130
What are the two types of symbiosis
1. Parasitism
2. Mutualism
131
What is parasitism
A parasite lives on another organism (the host) from which it obtains food
132
what two things does parasitism do
1. Benefits the parasite (energy or nutrients)
2. Harms (or kills) the host because of loss of resources
133
Define mutualism
a specialist relationship between two organisms that is beneficial to both
134
What three ways can parasites transmit to new hosts
1. Direct contact (e.g. Head-lice)
2. Resistant stages where the organism is able to survive adverse conditions until a new host becomes available (e.g. cat fleas)
3. Use of a vector (e.g. mosquito carrying plasmodium, the organism responsible for malaria)
135
What are vectors
Organisms, usually insects and tics, that transmit parasites
136
Why can’t parasites often survive out of contact with a host
They have a limited metabolism
137
What do secondary hosts allow parasites to do
Complete their lifecycle (e.g. tapeworm)
138
What are four advantages to living in social groups
1. Protection
2. Easier to catch food
3. Help raising young
4. Finding mates
139
What is a social hierarchy and what two things does it consist of
A rank order within a group of animals consisting of dominant and subordinate animals
140
Give two examples of social hierarchy
Pecking order in birds and hierarchy in wolves
141
What are the roles of dominant and subordinate animals
Dominant individuals carry out ritualistic (threat) displays whilst subordinate animals carry out appeasement behaviour to reduce conflict
142
Why do animals often form alliances in social hierarchy’s
To increase their social status within the group
143
What are three advantages of social hierarchy (why do they improve species survival)
1. Aggression between members is ritualised, so real fighting is kept to a minimum
2. Experienced leadership is guaranteed
3. Most powerful (fittest) will pass on their genes to the next generation
144
What is co-operative hunting and give three examples of species who do this
When predatory animals will hunt together, as groups, to increase their hunting success. E.g. wild dogs, wolves and killer whales
145
For what three reasons does cooperative hunting benefit both subordinate and dominant animals
1. They may gain more food than when foraging alone
2. Less energy is used per individual
3. Larger prey can be caught and increases chance of success
146
What is altruistic behaviour and give an example
Unselfish behaviour which is detrimental to the donor and beneficial to the recipient. E.g one meerkat standing guard whilst the others eat
147
What are the two possible explanations for altruistic behaviour
1. Reciprocal altruism
2. Kin selection
148
What does reciprocal altruism involve
One animal giving help to another animal in the prospect of the favour being returned
149
Give an example of reciprocal altruism
Grooming to remove parasites in primates
150
Why will the donor benefit in kin selection
Increased chances of survival of shared genes in the recipients offspring or future offspring
151
Define a social insect
One that lives in a colony or community with other individuals of the same species
152
Give four examples of social insects
1. Bees
2. Wasps
3. Ants
4. Termites
153
Who contributes reproductively in social insects’ societies
Only some individuals (queens and drones)
154
What are most members of a colony of social insects and what do they do
Sterile workers who cooperate with other workers to raise the queen’s offspring (their relatives)
155
Give three examples of roles of worker insects (as well as helping to raise relatives)
1. Defending the hive
2. Collecting pollen
3. Carrying out waggle dances to show the direction of food
156
How are primates able to learn their complex social behaviours
Through their long period of parental care
157
What supports the social hierarchy in primates
Complex social behaviours
158
What reduces conflict in primates
Ritualistic displays and appeasement behaviour
159
What are four of primates social behaviours
1. Grooming
2. Facial expressions
3. Body posture
4. Sexual presentation
160
What increases social status in a group of primates
Alliances
