Sustainability And Interdependance Flashcards
1
Q
light which strikes a leaf may be:
A
reflected, transmitted, absorbed
2
Q
net assimilation
A
increase in mass due to photosynthesis minus the loss due to respiration
3
Q
productivity
A
rate of generation of new biomass per unit area per unit time
4
Q
biological yield
A
total plant biomass
5
Q
economic yield
A
mass of desired product
6
Q
harvest index
A
dry mass of economic yield/dry mass of biological yield
7
Q
Why does livestock produce less food per unit area than plant crops?
A
due to loss of energy between each trophic level
8
Q
When is livestock production possible?
A
in habitats unsuitable for growing crops
9
Q
Ways of improving yield for plant crops
A
breeding of higher yielding cultivars, use of fertilisers, protecting crops from pests, disease and competition
10
Q
What is energy captured by photosynthetic pigments for?
A
to generate ATP for photolysis
11
Q
Photosynthetic pigments:
A
chlorophyll a and b, carotene, xanthophyll
12
Q
Chlorophyllls a and b:
A
- absorb blue and red light
- participate directly in light reactions
13
Q
What are carotenoids for?
A
they absorb other wavelengths of light and this energy is passed onto chlorophyll (accessory pigments)
14
Q
Why are accessory pigments important?
A
increase energy available for photosynthesis
15
Q
site of photolysis
A
grana of chloroplast
16
Q
site of carbon fixation
A
stroma of chloroplast
17
Q
What does absorbed energy do in the pigment molecule?
A
excites the electrons, transfer of these high energy electrons through the ETC releases energy to generate ATP by ATP synthase, also used for photolysis
18
Q
Process of Photolysis
A
- Light energy used to split water into hydrogen and oxygen
- Oxygen is released
- Hydrogen binds to acceptor NADP to form NADPH2
- Photophosphorylation- chlorophyll makes energy available for regeneration of ATP from ADP and Pi
- NADPH2 and energy held in ATP used for carbon fixation
19
Q
Calvin Cycle
A
involves reduction of carbon dioxide to glucose in a cycle of enzyme controlled reactions
20
Q
what enzyme controls calvin cycle?
A
Rubisco
21
Q
Process of Calvin Cycle
A
- Rubisco fixes carbon dioxide by attaching it to RuBP
- 3-phosphoglycerate produced is phosophorylated by ATP and combined with hydrogen from NADPH2 to form G3P
- G3P is used to regenerate RuBP and for synthesis of glucose
22
Q
glucose can be used for:
A
respiration, starch, cellulose or biosynthetic pathways
23
Q
Why is selective breeding used?
A
for improved plant crops and animal stocks, to support sustainable food production
24
Q
advantages of selective breeding
A
higher crop yield, higher nutritional value, pests and disease resistance, ability to thrive in particular environmental conditions
25
Why are plant field trials carried out in a range of environments?
to compare the performance of different cultivars or treatments and to evaluate GM crops
26
Factors to be taken account of when designing plant field trials:
the selection of treatments (to ensure fair comparisons), the number of replicates (to take account of the variability within the sample) and the randomisation of treatments (to eliminate bias when measuring treatment effects)
27
Why are self-pollinating plants less susceptible to inbreeding depression?
- naturally inbreeding
- due to the elimination of deleterious alleles by natural
selection
28
inbreeding=
selected plants or animals are bred for several generations until the population breeds true to the desired type due to the elimination of heterozygotes
29
outbreeding=
fusion of two gametes from unrelated members of the same species
30
inbreeding depression=
occurs due to the accumulation of recessive,
| deleterious homozygous alleles
31
naturally outbreeding species=
cross-pollinating plants and animals
32
How can inbreeding depression be avoided in outbreeding species?
selecting for the desired characteristic while maintaining an otherwise genetically diverse population
33
Why are test crosses used?
to identify unwanted individuals with heterozygous
| recessive alleles
34
What is produced when individuals from different breeds reproduce?
a new crossbreed population with improved characteristics
35
In crossbreeding, what is required to maintain a new breed?
a process of selection and backcrossing
36
hybridisation=
mating of two different homozygous cultivars of plant species producing offspring that are uniformly heterozygous
37
pros of F1 hybrids=
increased vigour and yield
38
F2 generation properties=
genetically variable
| little use for further production although it can provide a source of new varieties
39
Role of genome sequencing in crossbreeding=
organisms with desirable genes can be identified and then used in breeding programmes
40
Role of genetic transformation techniques in selective breeding=
allow one or more genes to be inserted into a genome and this genome can then be used in breeding programmes
41
What do weeds, pests and diseases do?
reduce productivity
42
invertebrate pests of crop plants=
insects, nematode worms and molluscs
43
plant diseases can be caused by=
fungi, bacteria or viruses, which are often carried by invertebrates
44
Selective chemicals=
act by killing specific weeds/pests/diseases
45
Systemic chemicals=
absorbed by a plant and travel throughout the plant's tissues
46
Properties of perennial weeds=
storage organs to provide a food source, the ability to reproduce by vegetative reproduction
47
Properties of annual weeds=
rapid growth, short life cycle, high seed
| output, long-term seed viability
48
Problems with plant protection chemicals=
toxicity to animal species, persistence in environment, can accumulate or be magnified in food chains
49
What is more effective than treating a diseased crop?
protective applications of fungicide based on disease forecasts
50
Integrated pest management
combines chemical and biological control
51
Chemical control
use of chemical pesticides to kill pests
52
Biological control
use of natural predators/parasites to kill pests
53
risks associated with biological control
predator being used becoming a pest itself
54
benefits of good animal welfare
faster growth rate, better quality products and increased reproductive success
55
ethology
study of animal behaviour
56
behavioural indicators of poor welfare
stereotypy, misdirected behaviour, failure in sexual or parental behaviour, altered levels of activity
57
stereotypic behaviour is
a persistent, repetitive movement that lacks function
58
misdirected behaviour is
a normal behaviour displayed in a different/inappropriate situation
59
What is an ethogram?
a description of an animal's observed behaviour
60
What can an ethogram be used for?
to form hypotheses on the animal behaviour that can be tested in natural or semi-natural surroundings. Info from these studies can be used to improve the environment for domesticated animals.
61
Why are preference tests used?
to determine which conditions are most conducive to the welfare of the animal
62
Why are measuremements of motivation used?
to determine the best conditions for the animal to be exposed to
63
symbiosis
co-evolved intimate relationships between members of two different species
64
parasitism
one organism benefits whilst the other is harmed by the
| interaction
65
How does a parasite benefit?
a parasite benefits in terms of energy or nutrients, whereas its host is harmed by the loss of these resources
66
Why can't parasite survive out of contact with a host?
they have a limited metabolism
67
transmission of parasites to new hosts using
vectors or secondary hosts, direct contact or through resistant stages
68
evidence for the symbiotic origin of chloroplasts and mitochondria
the size of the ribosomes found in chloroplasts being similar to that of ribosomes in prokaryotes
69
mutualism
both organisms benefit from the interaction
70
organisms in mutualistic relationships...
exchange metabolites and are structurally compatible
71
social hierarchy
consists of a rank order of dominant and subordinate
| individuals
72
behaviours that are adapted to group living
social hierarchy, cooperative hunting and social defence
73
altruistic behaviour
harms the donor individual but benefits the recipient
74
When is altruistic behaviour common?
if they are related- kin selection involves strategies that favour the reproductive success of an organism’s relatives at a cost to an organisms own survival and reproduction
75
How will the donor benfit in kin selection?
increased chances of survival of shared genes in the recipient's offspring or future offspring
76
social defence mechanisms
protects large numbers of induvidual animals
77
cooperative hunting
benefits subordinate and dominant animals
| By cooperative hunting, large prey can be killed which would be impossible for solitary animals
78
social insects examples
bees, wasps, ants
79
Why are social insects of ecological importance?
often keystone species within their ecosystems.
80
How are some social insects of economic importance to humans?
provide ecosystem services such as pollination and pest control
81
Social insect society structure
only some individuals (queens and drones) contribute reproductively, most members of the colony are workers who cooperate with close relatives to raise relatives
82
How do primates learn complex social behaviour?
long period of parental care
83
What behaviours are used to reduce conflict?
ritualistic display and appeasement behaviours including grooming, facial expression, body posture and sexual presentation
84
In some monkeys and apes, why are alliances often formed between individuals?
used to increase social status within the group
85
What do the social structures of different species of primate depend on?
ecological niche, the distribution of the resources they require and their taxonomic group
86
measurable components of biodiversity
species diversity, genetic diversity, ecosystem diversity
87
What are megafauna?
large animals that are susceptible to extinction because of human activities
88
Why is the present extinction rates higher than the natural background extinction rate?
escalating rate of ecosystem degradation caused by humans
89
How has biodiversity been regained after each mass extinction event?
speciation of survivors
90
Is estimating both past and current extinction rates accurately easy?
No, it is difficult
91
genetic diversity
the genetic variation represented by the number and frequency of all the alleles in a population
92
species diversity
comprised of species richness (number of different species in an ecosystem) and relative abundance ( proportion of each species)
93
What effect does a dominant species have on a community's biodiversity?
decreases in biodiversity compared to community without a dominant species
94
Factors which determine the species diversity found in an isolated ecosystem such as an island:
size (area) of the island and the degree
| of isolation
95
Why do small islands have a lower species diversity than large islands?
lower immigration rates and higher extinction rates
96
Example of species affected by overexploitation
Some fish species in North Seaby overfishing
97
Population bottleneck
an evolutionary event when a significant percentage of a population is killed or prevented from reproducing
98
Why is population bottleneck critical to some species?
Inbreeding results in poor reproductive rates
99
Habitat fragmentation:
is the breaking up of an organism's habitat, caused by geological processes or human activities
100
Species richness of habitat fragments
lower species richness
101
What reduces the size of habitat fragments?
degradation
102
What may edge species do?
invade the habitat at the expense of the interior species
103
Purpose of habitat corridors
to link isolated fragments allowing species to move between habitat fragments to feed, mate and recolonise habitats after local extinctions
104
introduced species
species that humans have accidently or intentionally moved to a new geographic location
105
naturalised species
introduced species that become established within wild communities
106
invasive species
naturalised species that spread rapidly and eliminate native species
107
invasive species properties:
- free of the predators, parasites, pathogens and competitors that limit their population in their native habitat.
- invasive species may also prey on native species and outcompete them for resources
108
climate change effect on biodiversity
reduces biodiversity
