SEED GERMINATION Flashcards
ripened ovule containing embryo
seed
seed characteristics
seed size
seed color
seed surface
types of seed based on the number of cotyledons
monocot
dicot
based on the presence of endosperm
albuminous
exalbuminous
these are the seeds with endosperm.
albuminous seeds
seeds without endosperm
exalbuminous seeds
in cereals such as maize, the seed coat is membranous and generally fused with the fruit wall known as
hull
stores food
endosperm
protective undifferentiated sheath of the radicle
coleorhiza
growing tip of the shoot
plumule
covers the plumule in monocots
coleoptile
outer thick protectice layer
testa
inner, thin membranous covering that protects the inner part of the seed
tegman
a scar on the seed coat
hilum
small pore present above the hilum
micropyle
ridge-like structure present around the median groove
raphe
the outer covering of the endosperm
aleurone layer
how seeds form
pollination
pollen tube
fertilization
growth of embryo/endosperm stops
seed reaches a dormant stage by gradual loss of moisture
indicated mostly by ripening or drying of fruits
maturation of seed
a mechanism that helps in the transport of seeds to other places to ensure germination and survival
seed dispersal
agents of seed dispersal
wind
expulsion
animals
water
seed dispersal by wind
anemochory
seed dispersal by water
hydrochory
seed dispersal by animals
zoochory
seed dispersal by explosions
autochory
rich in carbohydrates
cereals
lipids and fats
oilseed
rich in protein
pulses
aromatic acid/alkaloids
spices
secondary metabolites
beverage and medicine
fibre from seeds
fibre
can survive extreme freezing or drying conditions during ex-situ conservation
orthodox seeds
cannot thrive in freezing or drying conditions for a long duration
recalcitrant seeds
cotyledons emerge above the soil by elongation of hypocotyls
epigeal
don’t emerge above the soil surface
hypogeal
growth of seed into a young plant
germination of a seed
seeds remain alive but inactive for a long period of time
dormant
seedling growth
by cell division
enlargement
differentiation of growing point
significance of seeds
perennation
dispersal
delayed germination
food