botany Flashcards
(137 cards)
1
Q
global population estimated
A
7.8 billion 9.7
2
Q
Photosynthesis
A
the process by which green plants and some other organisms use sunlight to synthesise nutrients from carbon dioxide and water
3
Q
Photoperiodism
A
the response an organism has to the changes in day length
4
Q
Transpiration
A
the action of releasing water through the stomata
5
Q
photosynthesis
A
6CO2+ 6H20- C6H1206+6O2
6
Q
respiration
A
C6H1206+6O2 6C02+6H20
7
Q
regulations of plant growth and development
A
Light, CO2, O2, Temperature, Water
8
Q
how many tonnes of carbon from atmosphere fixed annually through photosynthesis via stomatal pores in land plants and through oceans
A
200 billion
9
Q
O2 required for aerobic respiration, cell repair, reproduction decrease in O2 <15% reproduction X <2.5% reproduction Y
A
X reduced, Y fails
10
Q
anaerobic conditions in flooded soil can lead to o XXX
A
ethanol toxicity in plant roots
11
Q
plant enzymes best operate at what temp ?
A
25 degrees
12
Q
viscosity of water
A
the measure if resistance of fluid to deformation at a given rate
13
Q
viscosity X as temperature increases
A
decreases
14
Q
viscosity if H20 is 2X as great @ 0 degrees as at 25 degrees
A
True
15
Q
leaf scorch may occur when
A
Early spring (when the soil is cold and the evaporating power of the atmosphere is high)
16
Q
weed
A
any plant not intentionally sown or propagated by the grower that requires management to prevent it from interfering from crop of livestock production
17
Q
what makes a plant a weed
A
wrong place
wrong time
yield loss through competition
reservoir for pest and disease
18
Q
when did weeds come about
A
10,000 years ago ice age
19
Q
when were row crops weeded by horses
A
1731
20
Q
when were tractors introduced
A
1920
21
Q
first herbicide when and name
A
1946 (2,4 D dicots)
22
Q
first herbicide when and name
A
1946 (2,4 D dicots)
23
Q
How many species of weeds
A
30,000
24
Q
Annual eg
A
completes lifecycle in 1 season/year eg fat hen
25
ephemeral
completes more than one lifecycle in 1 season year hairy bittercress
26
Biennial
develops vegetatively in the first yr and then flowers and sets in the second year and dies ragwort
27
periennel
lives for three or more years dock
28
reasons for weed success
rapid seedling growth
ability to grow in unfavourable conditions
competition
high photosynthetic rate
29
agronomic characteristics of weeds
look similar to crops
mature at the same time
tolerance to herbicide
seeds remain viable in the soil for a long time
30
Allelopathy -
one organism produces biochemicals which influence the growth survival development and reproduction of another organism
31
weed dispersal characteristic
Prolific
water
wind
animals
32
ragwort toxic to who
Cattle, horses, deer, goats pigs and chickens
33
Creeping thistle
affects crop yields and causes grassland problems
34
Non native weeds
Japanese knotweed
giant rhubarb
giant hog weed
35
Root functions
1. water uptake
2. anchoring
3. binding the soil together
4. nutrient capture
36
Sporophytes
Plants that has spores
37
First structure to appear when a seed germinates
Primary root
38
roots that branch off the primary root
secondary root
39
storage roots
adapted to store products photosynthesised in the shoot
40
Air roots
roots grow above ground of water and allow O2 to be transported to the inner cortex of the root system and C02 escape from the root interior
41
buttress roots
vertical flattened roots that project out of the ground and lower trunk
42
Prop/silt roots
adventitious roots that develop on a trunk or lower branch that begin as aerial roots but eventually grow into a substrate of some time
43
Sexual reproduction
Produces offspring by the fusion of egg and sperm genetically different parents
44
asexual reproduction
produced offspring without the fusion of egg and sperm. offspring are genetically identical to the parent (clones)
45
X% pollination in biotic Y% is abiotic
80%. 20%
46
Self pollination
pollen from one flower pollinates the same flower of other flowers on the same plant wheat, barley, rye
47
Sexual reproduction produces what
Seeds
48
Advantages of sexual reproduction
1. variation
2. adaptable to new environment
3. reduced competition
49
Disadvantages of sexual reproduction
1. two parents
2. fertilisation is random so harmful variations
3. flowers and seeds energetically expensive
50
Advantages to asexual reproduction
1. 1 parent plant
2. rapid colonisation
3. no genetic variation ( benefit in commercial horticulture)
51
Disadvantage to asexual reproduction
1. increased competition
2. cant adapt
3. adverse conditions likely to affect all individuals
52
seed dormancy
1. extremely low metabolic rate
2. suspension of growth and development
3. germination occurs when seedling is like to survive
53
Certified seed
seed that is handled so as to satisfactory maintain genetic identity and purity and that has been approved and certified by the certifying agency
54
seed storage
maintenance of high seed germination rate and vigour from harvest until planting
55
Prinicples of seed storage
1. conditions dry and cool
2. pest control
3. proper sanitation in seed stores
4. moisture limits
5. store high quality seed only well cleaned treated
56
natural selection
natural adjustment of genetic make up through generations over time .
57
Genetic engineering
involves the created of recombinant DNA which is inserted into the genetic material of a cell or virus
58
N2O
3rd most important long lived anthropogenic GHG
59
Ammonia volatilisation
process of ammonia volatillization commonly takes place when nitrogen is in an organic form called urea. most likely to take place when soils are moist and warm and source of urea is on or near the soil surface . will also take place on alkaline soils (ph > than 8)
60
role of S
protein - enzymes
S-S bonds link amino acids
Photosynthesis N fixation
Plant deficiency- chlorosis and stunted growth
61
virus move through cell junctions called
plasmodesmata
62
who spreads the Potatoe virus (PVY)
Aphids
63
Stages off Zadoks scale development
1.tillering
stem extension
heading
4. ripening
64
GS 31
first node detectable
key timing in crop management
-nutrient application
- growth regulator
-fungicide applied for control of fungal disease
- herbicide use to control weeds
65
yield components in cereal crops
ears/m^2 x grains/ear x grain weight (mean 1,000 grain weights)
66
non chemical control of weeds
topping
grazing
dense scar
avoid reintroduction on weed seeds in FYM
67
10% Weed infestation =
10% loss in forage yield
68
withdrawal of livestock after spraying
7-14 days
69
cutting interval after spraying
1-4 weeks
70
Pseudomonas syringae
infects a range of species
71
market value for cut flowers and fresh foliage is around X billion annually
16
72
shot hole disease on cherry laurel is a serious problem number of nursey stock with it
30%
73
Procambium
meristematic tissue concerned with providing the primary vascular system
74
osmosis
diffusion of water across a semi permeable membrane
75
cell sap
Is the liquid inside the large central vacuole of a plant
76
where do annuals thrive
frequently disturbed sites
77
biennials where do they thrive
not tolerant of tillage
permanent pasture waterways roadside areas
78
can prenennials regrow after removal of aboveground biomass?
yes
79
chemical control spraying control
overall spraying
patch spraying
spot spraying
80
thicker perennial stems what do they form
thinner '' '' ''
form conduits to distribute water and nutrients serve as stores and support above ground structures
thinner longer structures to absorb water and nutrients
81
Monocotyledon
typically elongated stalkless leaves with parallel veins
grasses
lilies
orchids
82
Dicotyledon
TWO cotyledons
broad stalked leaves
net like vines
oaks
spinach
rose
83
the root
is the organ of a plant that typically lies below the surface of the soil
typically develops from the radicle
growing downwards into the soil anchoring the plant and absorbing nutrients and moisture
84
Adventitious roots
roots that arise from anything other than the radicle
85
Apomixis
is asexual reproduction that produces seeds without the fusion of egg and sperm i.e it is clonal.
can occur in 2 ways :
embryo arises from an unfertilised egg cell
embryo is formed directly from some part of egg cell
86
Sexual reproduction is good in what environment
unstable
87
Seed germination
imbibition
serotiny- fire required to release seeds from plant
stratification - cold period to break dormancy( low metabolic rate, won't germinate until it will survive, growth and development suspended)
Scarification- seed coat damaged
substantial rainfall- desert plants
dark (most seeds)
light (lettuce, celery)
88
largest clonal colony fungi
blue mountains Oregon
89
largest clonal colony- tree
Utah, 47,000-60,000 trees
roots- 80,000 years old
90
agaves can sprout what within 5 hours
new roots
91
coco de mer
mature fruit 15-30kg
requires 6-7 years to reach maturity
2 years to germinate
92
why don't plants freeze to death
bud protected by hairs , wax, pitch
sugar concentration lowers freezing point
alter lipids in membrane
93
largest undivided leaf
giant ornamental rhubarb
94
largest aquatic leaf
giant amazonian waterlily
95
VOC
Volitile organic compounds
96
worlds largest individual flower
stinking corpse lily
97
worlds largest inflorescence
Talipot palm
98
worlds smallest plant
wolffia spp
99
xylem
carries the water taken in by the root hairs and epidermis UP the plant to the stems and leaves
100
Phloem
carries food produced by the leaves DOWN to the roots to be stored in the cortex
101
Endodermis
the inner boundary of the cortex: one cell layer thick controls the movement of water and minerals into the xylem and phloem
102
pericycle
a layer found inside the endodermis which may produce lateral roots
103
in contrast with the rests of the cortex the endodermis lacks X
cell walls contain SUBERIN in a band ( the Caspian strip)
air space
104
Apical meristem
region of cells capable of division and great on the root and shoot
cells divide once or twice a day
105
protoderm
a thin outer layer of the meristem in embryos and growing points of roots and stems which gives rise to epidermis
106
Ground meristem
forms the ground tissue(cortex)
107
Procambium
forms the primary phloem and xylem (vascular cylinder)
108
Root hairs are X
Short lived and older parts of the roots are hairless
109
Mucilage (Mucigel)
gelatine like substance secreted by root which allows organisms live underground
110
Water potential is measured in
megapascals (MPa)
111
water potential
is the measure of the tendency go theses molecules to diffuse to another area. the more free water molecules the higher the water potential
112
Plasmolysis
it will exhibit shrinkage
113
Turgid
swollen
114
Active transport
water is absorbed due to activities going on in the roots. absorption of water occurs with the help of energy in the form of ATP. absorption takes place AGAINST concentration gradients. even when the conc of cell say is lower than that of water.
115
Passve transport
passive absorption is by osmosis. takes place along the concentration gradients- when conc of cell sap is higher than that of soil water. water is absorbed when transpiration rate is high or soil is dry.
116
root hairs
collectively provide enormous surface area
almost always turgid because their water potential is > than that of soil
117
Apoplast route
movement through the cell WALLS and space between cells
118
symplast route
a cytoplasm continuum between cells connected ny plasmodesmata
119
Transmembrane route
membrane transport between cells and across the membrane of vacuoles within cells.
120
Cortical cells
numerous interconnections both via cell walls and via plasmodesmata which link the protoplasm of each cell...
121
Aquaporins
water Chanels that exist in the calomel and cell membrane
they speed up osmosis without changing the direction of water movement
122
Mechanisms of water movement through Xylem
Transpiration Pull
it is the pulling force responsible for lifting the water column. As water is lost in form of water vapour to atmosphere from the mesophyll cells by transpiration, a negative hydrostatic pressure is created in the mesophyll cells which in turn draws water from veins of the leaves.
Cohesion Adhesion Forces;
the water molecules in the chain are held together by hydrogen bonds which exist between neighbouring water molecules ....
Root pressure
caused by active transport of mineral nutrient ions into the root xylem.
123
factors affecting water absorption in plants
Soil Factors
water content
soil temp
soil aeration
flooding
texture and structure
speed of water movement
effective root zone
Atmospheric factors
temperature
relative humidity
Vapour pressure deficit ( VPD)
Wind speed
124
Endophytes
bacteria or fungi that live within plants
125
endophytes form what kind of relationships
beneficial symbiotic to parasitic
126
beneficial associations with both bacteria and fungi
Mycorrhizae increase the effective surface area of the roots
bacteria can supply an available source of N to the plant (in exchange for carbohydrates )
127
fungi and oomycetes reproduce
Asexually and sexually via spores zoospores
128
fungi and oomycetes grow via
hyphae
129
Fungi and Oomcyeyes are X closely related
fungi related to animals
oomyctes related to algae
130
Cell wall
rigid layer composed of cellulose.
protects and provides structural support
131
cell membrane
semi permeable helps in regulating what substances come in and out
132
nucleus
vital part of the cell. contains DNA info for growth and division
133
Vacuole
most of the cell surrounded by vacuole
support against pressure of cell wall stores toxins swell
134
ribosomes
site of protein synthesis protein factory
135
mitochondria
breaks complex molecules down and provides energy powerhouse cell
136
Ground tissue
parenchyma- thin walls photosynthesis in leaves and storage roots
collenchyma-shoot support
sclerenchyma -dead thick cells
137
where are endophytic bacteria mostly found
above ground tissue (intercellular spaces xylem vessels)
