Past paper R2101 sep 2020 Flashcards
what is meant by GENUS?
a sub-group of a family.
consist of a group of species which have similar characteristics
Give examples of genus plants
Rosa, Betula, Helleborus
What is meant by species?
a sub group of the genus
the rank below genus.
A group of plants with similar characteristics so can interbreed.
examples of species
Alchemilla mollis
Fagus sylvatica
what is the meaning of the term “cultivar”?
cultivar= cultivated variety.
often bred and need maintaining to keep that form.
can occur naturally in wild, but would still need to be selected and maintained by humans
examples of a cultivar
Bergenia cordifolis ‘Purpurea’
where does starch storage take place?
pith and cortex
where does mineral transport take place in the tissue of a young dicot stem?
xylem (think of the young dicto stem diagram)
where does cell division take place in the tissue of a young dicot stem?
vascular cambium
describe two differences between a dicot and a monocot stem
dicto: vascular bundles arranged in a ring
undergo secondary thickening/woody
monocot: have no vascular cambium
non-woody/no secondary thickening
herbaceous
scattered vascular bundles
what is the main function of a leaf?
photosynthesis
some examples of leaf adaptions are?
leaf spine Bulb Tendril Bract Stinging Hairs succulent leaves needles thick, waxy cuticle
what is the purpose of a leaf spine? Give a plant example
defense/protection from herbivory
eg: Berberis darwinii (looks like gorse)
What is the purpose of a bulb and name a plant example
for starch storage or perennation.
eg: Narcissus pseudonarcisssus (daffodil)
What is the purpose of a tendril, name a plant example
climbing so leaves can access maximum light for photosynthesis.
To hold flowers in best position for pollination
To hold fruits in best position for fruit/seed dispersal
eg: Lathyrus odoratus (Sweet Pea)
What is the function of a bract? Give a plant example
To attract pollinators.
eg: Euphorbia pul-cherri-ma
what is the purpose of leaf hairs/stinging hairs?
name a plant example
reduce water loss
protect from predators
EG: Urtica dioica (Nettle)
What is the purpose of succulent/fleshy leaves?
Name a plant example
To store water.
eg: Sedum spectabile
What are the purpose of needles?
name a plant example
To reduce water loss
eg: Taxas baccata (yew tree)
What is the purpose of the thick, waxy cuticle?
name a plant example
To reduce water loss.
eg: Ilex aquifolium (holly)
state the difference between juvenile and adult growth in the plant life cycle
Juvenile: non-flowering, can’t reproduce, vegetative growth
Adult: produces flowers and can reproduce
what are the benefits of juvenile growth in horticulture?
stem cuttings root more easily
hedges pruned regularly retain juvenile foliage so look decorative in winter
foliage is attractive in garden border/floristry
mowing lawns maintains lush growth (leafy sward)
coppicing stems provides attractive colour in garden border
what are the benefits of adult growth in horticulture?
flower/fruit production are decorative
scent from flower/fruit attracts insects to a border
flower production to for cut flower displays or on pot plants
seed production for propagation/breeding
seed/fruit production for a food crop
what are the PRODUCTS of aerobic respiration?
carbon dioxide, water and energy
what are the PRODUCTS of anaerobic respiration?
carbon dioxide ETHANOL and energy
what is the significance of aerobic respiration in propagation?
it is required for growth of the embryo in seed germination
needed for the production of new roots in cuttings
both of these make new cells
what does respiration break down in seeds and why?
Starch, to release energy
where is starch stored in a seed?
in the endosperm and cotyledons
a good supply of what is needed for aerobic respiration in germinating seeds/cuttings?
oxygen
why must compost be well aerated?
to provide a good supply of oxygen
to speed up the rate of respiration for germination or rooting, what is required?
a suitable temperature
to prolong the length of time seeds can be stored, what rate should you try to reduce?
respiration.
what does the cell membrane do?
controls movement of substances in and out of cell
produces cell wall
encloses cell contents
what does the nucleus do?
contains DNA-packed with chromosomes.
control centre of cell
what does the cell wall do?
controls shape of cell, and protects it from pathogens
is elastic and once matures becomes rigid to set its final shape.
What is the function of the mitochondrion?
it is the sire of respiration
what is the function of the vacuole and what does it contain?
contains water
stores minerals/pigments/waste products.
controls cell turgor
how is the stamen adapted for wind pollination?
they hang outside the flower
the anthers are not fixed so can move in the wind
filaments are flexible
large amounts of smooth/light pollen produced
how is the stamen adapted for bee pollination?
stamen is rigid so can brush against bee
pollen large, but small amounts
surface is rough
how is the petal adapted for wind pollination?
small and insignificant.
dull, often green in colour
how is the petal adapted for bee pollination?
brightly coloured (purple/yellow)
have nectar guides/nectaries
scented
landing platform for the bee (salvia)
Name a wind pollinated plant
Tarraxacum officinale (dandelion)
Betula pendula
Zea mays (corn)
Name a bee pollinated plant
Digitalis purpurea (foxglove)
Describe the pathway of water movement through the leaf from the stem to the air
Transpiration. (creates a pull that moves water up roots)
water enters plant through root hairs through osmosis
as roots take on more water, pressure builds and pushes existing water through cortex
It enters xylem cells through osmosis
water evaporates through the stomata in the leaves, exiting as vapour into the surrounding air
describe how light quality effects the rate of photosynthesis
chloroplasts absorb light-red and blue wavelengths.
chloroplasts reflect green light
the less light-the slower the rate of photosynthesis.
PAR= photosynthetically active radiation
what does PAR stand for (in photosynthesis)
photosynthetically Active Radiation
what are the range of light wavelengths for photosynthesis?
400nm and 700nm
how does the amount of available carbon dioxide affect the rate of photosynthesis?
the rate of photosynthesis increases as the levels of available carbon dioxide increases
how can growers optimise the conditions for photosynthesis?
light:
keep glasshouses clean to maximise light penetration
in shorter days provide light of correct wavelength eg: high pressure sodium lamps
avoid overcrowding (leaves can intercept as much light as possible)
position plants to provide optimum light outside according to their sun/shade requirements
remove overhanging vegetation
Temperature: install fan heaters to increase optimum temps
shade using blinds/ventilation/damping down to reduce temp and avoid stomatal closure
Nutrients: apply fertilisers to ensure adequate supply
Water; avoid wilting of foliage and stomatal closure so use suitabke irrigation methods (apply mulch to boarders)
name the flower part from where the seed develops from
the ovule
name the flower part from where the fruit develops from
the ovary
what is the function of the cotyledon?
storage of starch for the developing embryo
protection of plumule in epigeal germination
what is epigeal germination?
germination of plant takes place above ground EG: common bean
what is the function of the cotyledon in epigeal germination?
photosynthesis (common bean)
what is the function of the plumule?
gives rise to the new shoot with leaves to carry out photosynthesis
what is the function of the micropyle?
point of entry of water and oxygen to trigger germination.
maintains dormancy whilst sealed
point of entry of pollen tube to deliver male gamete to ovule for fertilisation
what is the function of the testa?
protects seed from the environment and pathogens.
holds seed contents together
involved in dormancy-keeps out water and oxygen
