New User Special Price Expires in

Let's log you in.

Sign in with Facebook


Don't have a StudySoup account? Create one here!


Create a StudySoup account

Be part of our community, it's free to join!

Sign up with Facebook


Create your account
By creating an account you agree to StudySoup's terms and conditions and privacy policy

Already have a StudySoup account? Login here

Chapter 22 Notes

by: Min-Young Kim

Chapter 22 Notes BIOL 3040

Marketplace > Clemson University > Biology > BIOL 3040 > Chapter 22 Notes
Min-Young Kim
GPA 4.0

Preview These Notes for FREE

Get a free preview of these Notes, just enter your email below.

Unlock Preview
Unlock Preview

Preview these materials now for free

Why put in your email? Get access to more of this material and other relevant free materials for your school

View Preview

About this Document

These notes cover the information regarding Chapter 22 of the textbook - development of the embryo.
Biology of Plants
Christina Wells
Class Notes
biology of plants
25 ?




Popular in Biology of Plants

Popular in Biology

This 3 page Class Notes was uploaded by Min-Young Kim on Thursday March 3, 2016. The Class Notes belongs to BIOL 3040 at Clemson University taught by Christina Wells in Spring 2016. Since its upload, it has received 19 views. For similar materials see Biology of Plants in Biology at Clemson University.


Reviews for Chapter 22 Notes


Report this Material


What is Karma?


Karma is the currency of StudySoup.

You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 03/03/16
Chapter  22  Notes  –  Early  Development  of  the  Plant  Body     -­‐ Embryogenesis:  first  two  phases  of  seed  development;  establishes  body   plan  of  the  plant;  accompanied  by  seed  development   o Apical-­‐basal  pattern  along  main  axis   o Radial  pattern  concentrically  arranged  tissue   -­‐ Formation  of  embryo  begins  with  division  of  zygote  within  embryo  sac  of   ovule   o First  division  is  asymmetrical  and  transverse  to  long  axis;  apical-­‐basal   polarity  is  established   § Chalazal  pole  has  apical  cell  that  gives  rise  to  most  of  mature   embryo   § Micropylar  pole  has  basal  cell  that  produces  suspensor  that   anchors  embryo  at  micropyle   • Polarity  fixes  the  structural  axis  of  the  body   • Through  orderly  divisions,  embryo  eventually  becomes   embryo  proper  and  suspensor.     • Developing  embryo  before  this  is  called  proembryo   -­‐ Changes  in  internal  structure  of  embryo  proper  result  in  concentrically   arranged  tissue  systems  (first  radial  polarity)   o Protoderm  formed  by  periclinal  divisions  (divisions  parallel  to   surface)  in  outermost  cells  of  embryo  proper   § Vertical  divisions  within  embryo  proper  result  in  ground   meristem  and  procambium.   • Ground  meristem  (precursor  to  ground  tissue)   surrounds  procambium  (precursor  to  xylem  and   phloem)   • Primary  meristems  (Protoderm,  ground  meristem,   and  procambium)  extend  into  other  regions  of  embryo   -­‐ Globular  stage:  when  embryo  is  spherical,  preceding  cotyledon  development   o Heart  shape  form  as  cotyledons  develop  into  eudicots  (heart  stage)   o In  monocots,  embryos  become  cylindrical  and  have  only  one   cotyledon   o In  both  monocots  and  eudicots,  apical-­‐basal  pattern  of  embryo  proper   first  becomes  discernible  prior  to  emergence  of  cotyledons     § Axis  partitioned  into  shoot  apical  meristem,  cotyledons,   hypocotyl,  embryonic  root,  and  root  apical  meristem   o Torpedo  stage:  cotyledons  and  axis  elongate,  primary  meristems   extend  along  with  them   o Apical  meristems  found  at  tips  of  all  shoots  and  roots;  repeated   division   -­‐ Angiosperm  suspensors  are  metabolically  active;  support  early  development   of  embryo  proper  by  providing  nutrients  and  growth  regulators   o Plasmodesmata  connect  cells  of  suspensor  with  those  of  developing   embryo  proper   o Suspensor  undergoes  programmed  cell  death   o In  mutants:  embryo  proper  is  presumed  to  transmit  specific  inhibitory   signals  to  suspensor  that  suppress  its  development  into  an  embryo   -­‐ Very  promising  results  obtained  in  identifying  genes  responsible  for  events   in  Arabidopsis  embryogenesis   -­‐ At  opposite  ends  of  embryo  axis  are  apical  meristems  of  shoot  and  root   o Some  embryos,  only  apical  meristem  occurs  above  attachment  of   cotyledons   o Others,  embryonic  shoot,  consisting  of  epicotyl  with  one  or  more   young  leaves  and  apical  meristem,  occurs  above  cotyledons.     § Plumule:  first  bud;  embryonic  shoot   § Stem-­‐like  axis  below  cotyledons:  hypocotyl   § Radicle:  lower  end  of  embryonic  root   § If  radicle  cannot  be  distinguished  in  embryo,  embryonic  axis   below  cotyledon  is  called  hypocotyl-­‐root  axis   -­‐ Most  or  all  of  food-­‐storing  endosperm  is  absorbed  by  developing  embryo  à   develop  large,  fleshy  cotyledons  that  nourish  embryo   -­‐ In  monocots,  single  cotyledon  functions  as  food-­‐storing/photosynthetic   organ,  and  absorbs  food  digested  from  endosperm  by  enzymatic  activity   o When  fully  formed,  grass  embryo  has  massive  cotyledon,  scutellum.   Radicle  and  Plumule  enclosed  by  protective  structures  called   coleorhiza  and  coleoptile     o Outer  covering  in  grass  seed  are  pericarp  (mature  ovary  wall)  and   remnants  of  seed  coat   o Micropyle  associated  with  scar,  hilum  (seed  separation  from  stalk)   -­‐ Seed  coat:  outer  coat  of  seeds  which  develops  from  integuments  of  ovule  and   provides  protection  for  embryo  (in  many  seeds,  very  hard  and  highly   impermeable  to  water)   -­‐ Maturation  phase:  second  phase  of  seed  development;  buildup  of  food   reserves  in  endosperm,  perisperm,  or  cotyledons   o Seed  undergoes  desiccation  as  it  loses  water   o Seed  coat  hardens   o Seeds  of  some  plants  then  enter  quiescent  state;  others  become   dormant   -­‐ Germination  affected  by  external  factors  like  water,  oxygen,  and   temperature   o Most  seeds  really  dry;  germination  doesn’t  begin  until  enzymes   already  present  in  seed  are  activated  by  water;  new  enzymes   synthesized  for  digestion  of  stored  foods   -­‐ During  early  stages  of  germination,  glucose  breakdown  may  be  entirely   anaerobic,  but  as  soon  as  the  seed  coat  is  ruptured,  the  seed  switches  to  an   aerobic  pathway   -­‐ Many  seeds  germinate  over  fairly  wide  range  of  temperatures  but  most  have   minimum  temp  between  0-­‐25°C  and  maximum  temp  between  45-­‐48°C   -­‐ Dormant  seeds  fail  to  germinate  even  when  external  conditions  are  favorable   o Coat-­‐imposed  dormancy:  impermeability  of  seed  coat  to  water  or   oxygen;  rigidity  of  seed  coat;  conifers,  most  cereals,  and  several   eudicots   o Embryo  dormancy:  ratio  of  abscisic  acid  and  gibberellic  acid   o After-­‐ripening:  physiologically  immature  seeds  undergo  complex   series  of  enzymatic  and  biochemical  changes  before  they  germinate   o Dormancy  acquired  during  seed  maturation  is  primary  dormancy;   seeds  that  are  no  longer  dormant  but  encounter  unfavorable   conditions  may  be  induced  to  secondary  dormancy   o Burls  or  lignotubers  on  shrubs  and  small  trees  contain  dormant   buds  that  sprout  after  shoots  are  damaged  by  fire   -­‐ When  germination  occurs,  the  first  structure  to  emerge  from  most  seeds  is   the  root   o Primary  root,  or  taproot,  continues  to  grow  and  develops  branch   roots,  or  lateral  roots   o Root  system  of  adult  plant  develops  from  stem-­‐borne  roots,  which   arise  at  nodes  and  produce  lateral  roots   -­‐ Garden  bean:  root  emerges  from  seed,  hypocotyl  elongates  and  becomes   bent,  hook  reaches  soil  surface,  straightens  out,  pulls  cotyledons  into  air;   epigeous   -­‐ Pea:  epicotyl  elongates  and  forms  hook,  straightens  out;  Plumule  is  raised   above  soil  surface;  cotyledons  remain  underground;  hypogeous   -­‐  Majority  of  monocot  seeds,  stored  food  is  found  in  endosperm   -­‐ Maize:  coleorhiza  encloses  radicle,  first  structure  to  grow  through  pericarp   -­‐ Period  from  germination  to  time  seedling  becomes  established  as   independent  organism  is  most  crucial  phase  in  life  history  of  plant  


Buy Material

Are you sure you want to buy this material for

25 Karma

Buy Material

BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.


You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

Why people love StudySoup

Jim McGreen Ohio University

"Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

Anthony Lee UC Santa Barbara

"I bought an awesome study guide, which helped me get an A in my Math 34B class this quarter!"

Bentley McCaw University of Florida

"I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

Parker Thompson 500 Startups

"It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

Become an Elite Notetaker and start selling your notes online!

Refund Policy


All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email


StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here:

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.