CHAPTER6
Seeds:St
ruct
ure&Ger
minat
ion
1.Ver
yshor
tanswer
s:Cor
rectt
hef
alsest
atement
a.Plumul
edevel opsintothesuit
esystem
b.tegmeni sthet hi
ninnerlayeroftheseedcoat
c.epit
hel
ium s eparatestheendosperm andembryoni
cregi
oni
n
themaizegr ain
d.hypocotylelongatesfasterinepi
gealgermi
nati
on
e.dormancyi stheper i
odoft herestaci
d
2.Namet
hef
oll
owi
ng
a.Mill
ets,cereal
s
b.pyrogall
icacid
c.coleopti
le
d.Rhizophora
e.Aleuronelayer
f.bean
3.f
il
li
nthebl
anks:
a.Hypocot yl,above
b.coleorhiza,coleopt
il
e
c.testa,tegmen
d.mi cropyle
e.car bohydrates.
4.Gi
vet
woexampl
esofeach:
a.Pal
m,mi
l
let
s
b.cust
ardappl
e,poppy
c.or
chi
dsVal
l
isner
ia
d.mangomust
ard
e.Rhizophora,sonnerat
ia
7.Namet hefoll
owing:
a.Monocotanddi cot
.
b.Albumi nousandexalbuminous.
c.H2O,t emper at
ureandoxygen.
d.Hypoger minat
ionandepigermi
nat
ion.
e.Testa, t
egmen
Shortanswert ype:
a)Seedi sar i
penedovule
b)Fr ui
tisanenl argedr ipenedovar y
c)Gr ainisact uall
yaf ruitinwhicht hef ruitwal l&t heseedcoatar e
fusedt oget her.
d)I tisast atei nadr yseedt heembr yoi si nactive.
e)I tisthepr ocessoff or mati
onofseedl ingdevel opedf rom the
embr yo.
2.Embr yo:Itist het i
nyl i
vingpar toftheseedr emai nsinact i
vebut
ger mi nateswhenexposur etof avorabl econdi ti
ons.
Seed:I tisar i
penedovul e.
3.Ger mi natedgr amsar econsi deredhi ghl ynut r i
ti
vebecauset he
cot yledonoft heseedabsor bsfoodf rom t heendosper m,maki ng
itnut ri
ti
ve.I tisr i
chinst archandi t
sout er mostl ayerisrichin
pr otein.
4.mai zegr aini sact uall
yaf rui
tinwhi cht hef ruitwallandt heseed
coatar ef usedt ogethert oform apr otect i
vel ayer.Ther efore,we
donotuset het er
msmazef rui
tandmai zeseedi nsteadwewe
cal lsuchf r
uitsasgr ai
ns.
5.LongAnswert ype:
1.
Monocot yledonous Di cotyledonous
seedscont ainonecot yledon seedscont ain2cot yledons.
.exampl e;Mai ze exampl e:Pea
Epi
cotyl Hypocotyl
t
heregi onoftheaxisbetween theregionoftheaxi
sbel
owthe
t
hepointoft heattachmentof cotyledonsiscal
l
edhypocot
yl
t
hecot yledonsandt hepl
umule
i
scall
edepi cotyl
Epigealgerminat
ion Hypogealgerminat
ion
cotyl
edonsar epushedabove cotyl
edonsremain
theground. undergr
ound.
2hypocot yl
elongates 2epicotyl
elongat
es
Radicl
e Pl
umul
e
radi
calfor
mst
her
ootsyst
em pl
umul
efor
mst
heshootsyst
em
Al
buminous Exal
bumi
nous
t
heseedsinwhi
cht
he t
heseedsi
nwhicht
he
cot
yledonsaret
hinand cotyl
edonst
oresf
oodand
membr anesandendosper
m becomesthi
ckandfl
eshy.
per
sist
s
2.Wr
it
ethef
unct
ionsoft
hef
oll
owi
ng:
a.Seedcoat:i
tpr
otect
sthedeli
cateinnerpar
tsoft
heseed
fr
om i
njur
yandtheattackofbacteri
afungi
andinsect
s.
b.Micropyl
e:dur
inggermi
nati
onmi cr
opi
l
eal
l
owswat
ert
o
entert
heseedt hr
oughi
tspore.
c.Cot
yledon:t
heycont
ainf
oodf
ort
heembr
yo.
d.Radi cal
:itformst hef utureroot
e.Plumul e:itformst hef utur
eshoot .
3.Exper i
ment2Pgno:52
4.Yes,wecal li
tger minationbecauseal lt
hechangesl eadingto
theformat i
onofas eedl ingcollectivel yconsti
tut
eger minat
ion.
Dur i
ngger minat i
on,eithertheepi cot ylorthehypocotyl
elongates.
5.Disti
nguishBet ween
Coleorhiza coleopt ile
protecti
vesheetofr adical prot ectivesheetofplumule
presenttowar dst hepointed presentt owardstheupper
endofembr yoni cregion bor dersi deoftheembr yonic
region
Beenseed maizegrai
n
2cotyl
edons onecotyl
edon
noendosper
m l
argeendosper
m pr
esent
germinati
on vivi
parous
whent heembryointheseed Vivi
parii
sknownasthe
becomesact i
vat
edandbegi ns germinati
onofseedwithi
nthe
togrowintoanewpl anttheni
t frui
twhil
eiti
ssti
l
lat
tachedto
i
sknownasger minat
ion theparentpl
ant.
6.Themai zegr ainisaoneseededf ruitbecausethefootbal
l
er
becauset hef r
uitwallandt
heseedcour tarefusedtoforma
protect
ivelayerasi ti
samonocot yledonousandendosper mi
c.
7.Thehypocot ylgrowsf ormi
ngal oopabovet hesoilitt
hen
st
raight
enspushi ngthecot
yledonsabovet hegr ound.
8.Diagram
a.Pgno: 54f i
g.6.8a
b.Pgno:54f i
g. 6.
8b
9.Pg no:
53f
ig
