Unit 3 Flashcards
(137 cards)
1
Q
what is food security?
A
the ability of human populations to access food of sufficient quality and quantity
2
Q
how can you increase food production?
A
breed at higher yielding cultivators
fertilisers
protecting crops from pests, disease and competition
3
Q
plant crop examples
A
cereals
potatoes
roots
legumes
4
Q
desirable characteristics breeders seek
A
high nutritional value
resistance to pests/disease
physical characteristics suited to harvesting
those that can thrive in particular conditions
5
Q
what can plants do with light?
A
absorbed
reflected
transmitted
6
Q
what are the uses of light energy absorbed?
A
generate ATP
produce hydrogen
split water
excite electrons
pump H+ across membrane
7
Q
visible light
A
each colour has a different wavelength
8
Q
types of photosynthetic pigments
A
chlorophyll A
chlorophyll B
Carotenoids (Xanthophyll and Carotene)
9
Q
chlorophyll A absorption
A
red and blue
10
Q
chlorophyll B absorption
A
red and blue
11
Q
carotenoids absorption
A
yellow and green
12
Q
absorption spectra
A
shows the absorption of each photosynthetic pigment at different wavelengths of light
13
Q
action spectra
A
shows the rate of photosynthesis at each wavelengths of light by the plant
14
Q
advantage of carotenoids
A
extends the range of wavelengths that a plant can use for photosynthesis
15
Q
how is light energy absorbed?
A
through chlorophyll
16
Q
what do the excited electrons do?
A
provides the energy for pumping hydrogen ions across the membrane
splits water into hydrogen and water
17
Q
what do hydrogen ions do in photolysis
A
pump through ATP synthase to make ATP
18
Q
how are hydrogen ions passed onto carbon fixation?
A
by NADP in the form of NADPH
19
Q
products of photolysis
A
oxygen
ATP
NADPH
20
Q
where does carbon fixation occur?
A
stroma
21
Q
where does photolysis occur
A
granum
22
Q
what enzyme combines CO2 and RuBP?
A
RuBisCo
23
Q
what does RuBisCo do?
A
combines CO2 and RuBP
24
Q
what do CO2 and RuBP form?
A
3GP
25
what happens to 3GP?
phosphorylated by ATP and combes with hydrogen to form NADPH
this makes G3P
26
what is phosphorylated in carbon fixation?
3PG
27
how is G3P made?
by 3PG getting phosphorylated and combining with hydrogen to form NADPH
28
what is G3P used for?
regenerate RuBp and used to synthesise glucose
29
uses of glucose
respiration
storage
structure
biosynthesis pathways
30
how is glucose used in respiration?
as a substrate or to provide energy
31
how is glucose used for storage?
carbohydrate starch
32
how is glucose used for structure?
carbohydrate cellulose
33
desirable characteristics in crops and animals
high yields
high nutritional value
pest and disease resistance
ability to thrive in particular environments
34
why are plant field trials carried out?
carried out in a range of environments to compare the performance of different cultivars and evaluate GM crops
35
what must be considered when designing a field trial?
selection of treatments
number of replicates
randomisation of treatments
36
what does selection of treatments do?
ensures a valid comparison
(shows cultivar has caused changed)
37
what does number of replicates do?
increases reliability
takes account of variability
38
what does randomisation of treatments do?
eliminates bias when measuring effects
39
what is true breeding?
both homozygous dominant and homozygous recessive
you always know which allele is passed on
40
what is inbreeding?
relatives are bred (for several generations)
41
positive effect of inbreeding?
population then breeds true due to the elimination of heterozygotes
42
when is inbreeding naturally occuring?
in some species of self-pollinating plants (peas, wheat, rice)
43
what is a negative consequence of inbreeding?
inbreeding depression
44
effects of inbreeding depression?
increase in the frequency of individuals who are homozygous for recessive deleterious alleles
individuals less likely to survive to reproduce
45
how are self-pollinating plants less susceptible to inbreeding depression?
natural selection over time can eliminate the deleterious alleles
46
what is cross breeding?
breeding different breeds together
47
what does cross breeding produce?
an F1 hybrid
48
what does cross breeding allow?
new alleles to be introduced
49
F1 hybrid traits
improved characteristics
heterozygous
hybrid vigour
50
what is hybrid vigour?
increase in vigour, yield, fertility
poor recessive genes are masked by superior dominant genes
51
when does hybrid vigour occur?
when crossbreeding occurs
52
what does a plant with an increased hybrid vigour show?
increased disease resistance
increased growth rate
53
why are F1 hybrids not bred together?
F2 generation show too much variation
so parents are maintained
54
what is a test cross used for?
a cross between an organism with an unknown genotype for a trait and an organism that is homozygous recessive for that trait
55
what does a test cross allow?
to determine the genetic makeup for the unknown organism
56
what is used in genetic technology?
genome sequencing
recombinant DNA technology
57
what does genomic sequencing do in genetic technology?
organisms with desirable genes can be identified then used to be bred
58
what does recombinant DNA technology do in genetic technology?
crop plants can be genetically modified
59
weed types
annual
perennial
60
annual weed characteristics
produce vast number of seeds
seeds viable for a long time
grow quickly
short life cycle
61
perennial weed characteristics
reproduce asexually
are already established in the habitat
have storage organs to provide food during poor conditions
62
types of pests to crop plants
insects
nematode worms
molluscs
63
how do pests destroy plants?
eat the leaves which reduces the plants ability to carry out photosynthesis
they can also be a vector for a disease which can damage the crop
64
plant disease examples
fungi
bacteria
viruses
65
cultural means of crop protection
weeding
ploughing
crop rotation
(non-chemical control)
66
chemical means of crop protection
herbicides
fungicides
insecticides
molluscicides
nematicides
(use of pesticides when cultural means fail)
67
two ways to protect a crop
cultural means
chemical means
68
types of herbicides
selective
systemic
69
selective herbicide
broad leaf plants
speeds up metabolism and they use up their food reserves and die
70
systemic herbicide
destroys whole plant and roots to prevent regrowth
71
pesticide characteristics
specific to pest
short life
safe for humans and animals
72
pesticide problems
toxic to non-target species
persist in environment
produce resistant population of pests
bioaccumulation in organisms
biomagnification in food chains
73
what is bioaccumulation?
built up of a chemical in an organism
74
what is biomagnification?
the increase in the concentration of a chemical moving between trophic levels
75
what is a biological control?
control of a pest population through:
predator
parasite
pathogen
76
negative to biological controls?
if an escape occurs into environment which it is free from predators, their number can rapidly increase and infect local population
77
what is integrated pest management
a combination of chemical, biological and cultural control
78
what does providing livestock with good environmental conditions involve?
costs
benefits
ethics
79
what is intensive farming
less ethical
conditions cost effective
generates higher profits as costs are lower
80
what is free range farming?
requires more land
labour intensive
sold at a higher price
animals have better quality of life
81
why are unstressed animals beneficial?
grow better
breed more successfully
generate higher quality of products
82
indicators of poor animal welfare
stereotypy
misdirected behaviour
failure in sexual or parental behaviour
altered levels of activity
83
what is stereotypy?
pattern of repetitive behaviour
pacing
tongue rolling
84
what is misdirected behaviour?
animal inappropriately direct its attention
chicken plucking their own/others feathers
85
what is symbiosis?
co-evolved intimate relationship between two species
86
what are the two types of symbiosis?
parasitism
mutualism
87
what is a parasite relationship?
the parasite benefits in terms of energy or nutrients whereas the host is harmed by the loss of these resources
88
how can parasites be transmitted?
direct contact
release of resistant stages
use of a vector
89
parasite release of resistant stages
its able to survive in adverse conditions until they come into with a new host
90
parasite use of a vector
passed through a another species such as an insect before in contact with the host
91
what does the parasitic life cycle involve?
intermediate hosts to complete their life cycle
92
benefits to intermediate hosts for a parasite
increased transmission
93
what is a mutualistic relationship?
both organisms benefit from an interdependent relationship
94
why do animals live in social groups?
protection
finding mates
easier to catch food
help when raising young
95
what behaviours do animals living in social groups have?
social hierarchy
cooperative hunting
social defence
96
what is social hierarchy?
found in large social groups where animals are ranked as a result of aggressive behaviour
97
what behaviours do dominant individuals show?
ritualistic threat displays
98
what behaviours do subordinate individuals show?
submissive appeasement behaviours
99
why do subordinate individuals behave the way they do?
to reduce conflict
100
advantages to cooperative hunting
gain more food than alone
less energy used so more energy gained
larger prey can be caught
increased chance of success
all members get a share
101
advantages of a social hierarchy
increased chances of dominant animals favourable alleles being passed onto offspring
animals often form alliances to increase status
102
what is social defence?
offers protection from predators while others eat and increases chances of surviving
103
what is cooperative hunting?
predatory mammals often hunt together as groups to increase hunting success
104
what is altruism?
unselfish behaviour which is harmful to donor and beneficial to recipient
105
types of altruism?
reciprocal
kin selection
106
what is reciprocal altruism?
one animal giving help to another in the prospect of the favour being returned
107
what is kin selection altruism?
the donor will benefit through the increased chances of survival of shared genes in the recipients offspring
occurs in close relatives
108
what are social insects?
have complex social behaviours where labour exists and workers show extreme altruism
109
examples of social insects
bees
wasps
ants
termites
110
what type of altruism do social insects show?
kin selection
111
what do social members do?
raise relatives
collect food and pollen
defend the hive
112
what do fertile individuals do?
carry out reproduction
113
what types of social insects are there?
sterile
fertile
114
what are primates and give examples?
group of placental mammals
humans
monkeys
apes
lemurs
115
why do primates do parental care?
allows them to develop complex social behaviours
116
examples of complex social behaviours in primates
communication
skills
play/social interaction
cooperation/sharing
117
components of biodiversity
genetic
species
ecosystem
118
genetic diversity
the number and frequency of alleles within a population
119
if a population of a species dies out then what would happen to its genetic diversity?
limit its ability to adapt to changing conditions
120
what is species diversity composed of?
species richness
relative abundance
121
what is species richness?
number of different species in an ecosystem
122
what is relative abundance?
the proportion of each species in the ecosystem
123
ecosystem diversity
the number of distinct ecosystems within a defined area
124
what is overexploitation?
resources are consumed at a faster rate than they can be replaced
125
effects of overexploitation
reduces the numbers in a population
reduces the genetic diversity of that population
126
what is the bottleneck effect?
evolutionary event in which a significant percentage of a population is killed off or otherwise prevented from reproducing
127
effect of the bottleneck effect
small populations may lose genetic variation
128
what is habitat fragmentation?
new habitat much smaller than the previous due to a geological process or human activity
129
what can degradation of edges cause to a habitat?
increased competition
decrease in biodiversity
lower species diversity
130
what are habitat corridors?
pathways of natural habitat which allow movement of animals between fragments
131
advantages to habitat corridors
increase access to food and choice of mate
lead to recolonisation of smaller fragments
132
introduced species
species that humans have moved to new geographical locations
133
naturalised species
species that become established within wild communities
134
invasive species
spread rapidly and eliminate native species reducing species diversity
135
why are invasive species able to spread rapidly?
a lack of:
predators
parasites
pathogens
competitors
that would normally limit their population
136
what can invasive species do to native species?
prey on them and out compete for resources
hybridise with them
137
