Activity No. 7A B S O R P T I O
NRootUndergroundportionoftheplant bodywhichservestoanchortheplant
bodytotheground,absorbwaterand inorganicnutrientsandconductwater
and mineral nutrients.Roots may be classified according to their
origin as:1. Primary rootDevelopfromthehypocotylsoritslo!er tip"
the radicle# of the embryo$. !econdary root "#ranch roots$Develop
as branches from the primary root and other roots$%. Adventitious
roots Developdirectlyfromthestemsand leaves$T!o basic types of root
system:%$ Taproot systemDerivesdirectlyfromthefirstrootthat
emergefromaseedthatenlargesandformsa
prominentcentralrootthatiscalledthetaproot$ e$g$ dicots#&$
'ibro(s root system)indofrootsystemin!hichbothprimary
andlateralrootsarefinelydividedandhave appro*imately e+(al
diameters$, Root cap - tiss(e at the very tip of the root a*is$,
&eristematic region - region of actively dividing cells" cells
divide and increase in n(mber$,Region of elongation - root hair
.one" cells enlarge and begin to differentiate$, Region of
maturation - region !here primary tiss(es are completely
differentiatedDicot root c$s#/onocotroot c$s#, 'pidermis - o(ter
layer of cells" it protects the inner
tiss(es$,(orte)-cellsbet!eentheepidermisand central part of the
root$,(entralcylinderorstele-thecells thro(gh the
center$,*asculartissues-cond(ctingtiss(es composed of the *ylem and
phloem$,Pericycle-atiss(ebo(nde*ternallyby the endodermis and
intenally by the phloem$!P'(+A,+-'. R//0!%$ 1leshy or enlarged
roots - are speciali.ed to store food and other materials$According
to shape:, 0onical - e*ample : 0arrot Da(c(s carota 1$#, '(siform -
e*ample : Radish Raphan(s sativ(s 1$#, T(berc(lar - e*ample : S!eet
potato Ipomoea batatas 1am2$#, 'ascic(lated - e*ample : 0assava
/anihot esc(lenta 0rant.$#, Napiform - e*ample : T(rnip Pachyrhi.(s
eros(s 1$# 3rb$#&$ Prop roots - add s(pport to the str(ct(re of
the plant$4*$ (orn - 5ea mays 1$4*$ Pandan - Pandan(s
amaryllifoli(s Ro*b$6$ Photosynthetic roots2 3reen roots -
speciali.ed to man(fact(re food for they have chlorophyll$ e*$
Orchids#7$ (linging root- roots that cling to !alls and tree tr(n2s
for s(pport$ 4*$ (adena de amor 0oral vine# Antigonon leptop(s 8oo2
and Arn$9$ Pneumatophore - may assist in getting o*ygen to the
s(bmerged roots$ e*$ /angroves#:$ (ontractile roots - gro! into the
soil and contract thereby p(lling the corm or b(lb into the soil$;$
(lustered fleshy root - for !ater storage 4*$ ,awiswis 4awayan -
0hlorophyt(m elat(m,argest 0ree Root !ystem
