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LU7 PLANT GROWTH AND DEVELOPMENT :black_flag: - Coggle Diagram
LU7 PLANT GROWTH AND DEVELOPMENT
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two classes of meristems :red_flag:
vegetative meristems
reproductive meristems
conditions for growth :red_flag:
water
plant growth is depends to water status of the plant
required for cell enlargement
turgidity
medium for enzymatic activities needed for growth
oxygen
help in releasing energy
nutrients
required by plants for synthesis of protookasm
temperature
a range of optimum temperature is needed
the angiosperm flower :red_flag:
male & female structures occur together in same individual flower
angiosperm reproduction
pollen grains develop from microspores formed in pollen sacs located in the another
pollination
self-pollination
pollinators often drawn to nectar
wind
eggs develop in ovules, & each ovule contains a megaspore mother cell
fertilization
pollen adheres to stigma
grow pollen tube that pierces the style
double fertilization
two sperm cells used forming embryo & endosperm
seeds
embryo is covered by the integument
outermost covering of ovuile develop into seed coat enclosing dormant embryo
stored food source
seeds cont
germination
resumption of metabolic activities that lead to growth
Photoperiodism & Dormancy :red_flag:
flowering responses
long-day plants
required a relatively longer day
wheat maize & radish
short-day plants
require a relatively short day
chrysanthemum & soya bean
day-neutral palnts
photoneutrals
cotton, pea, tomato & sunflower
help in maintain the circadian rththm
internal clock
measures the length of night & day
tropisms
growth responses of plants to external stimuli
growth towards directional sources of light
gravitropism
stems grow upwards & roots downward
thigmotropism
response of plants to touch
