Plant Evolution

12 Pages
108 Views
Unlock Document

Department
Biology
Course
BIOL 1113
Professor
Mary- Susan Potts- Santone
Semester
Spring

Description
•  Among  largest  living  organisms   •  Primary  organisms  producing  oxygen  as  a  result  of  photosynthesis   •  Our  survival  is  dependent  on  producers  (plants)   •  Base  of  food  chain   •  Terrestrial  environment  –  more  light  and  carbon  dioxide  available,  so  more   advantageous  to  run  photosynthesis   •  Plants  started  off  near  bodies  of  water  (roots,  carbon  dioxide,  sunlight  necessary   for  photosynthesis)   •  Plants  needed  transport  and  support  system   •  Terrestrial  plants  –  need  to  protect  all  phases  of  reproduc▯on   •  Apical  cells  –  found  at  ▯ps  of  roots  and  stems,  allow  plants  to  con▯nually  grow   throughout  their  life▯me     •  Plasmodesmata  –  channel  that  allows  cells  to  communicate   •  Placenta  –  provides  nutrients,  resources,  and  protec▯on  for  next  genera▯on   (haploid  cells  of  one  genera▯on  to  diploid  zygote  of  next)       1 •  Evolu▯on  of  plants  marked  by  4  major  events   •  Each  major  event  is  associated  with  the  evolu▯on  of  a  par▯cular  group  of   plants   •  Nonvascular  plants   •  Prevents  embryo  from  drying  out,  provides  mechanism  from  which  embryo   can  be  dispersed   •  No  transport  system   •  Plants  typically  small   •  Vascular  system   •  Transport  system,  transports  water  and  nutrients  throughout  plant   •  Allows  plants  to  be  larger   rd •  3  major  event  –  ability  to  produce  seeds  (gymnosperms  and  angiosperms)   •  Seeds  allow  for  dispersal   •  Seeds  contain  embryo  and  stored  food  for  embryo  and  allow  for  dispersal   of  plant  into  new  environment   •  Flowering  plants   •  Fruits  another  way  for  seeds  to  be  contained  and  dispersed  into   surroundings   •  A▯ract  pollinators  -­‐  evolu▯on  of  plants  and  insects  ▯ed  together   2 •  Alterna▯on  between  a  diploid  mul▯cellular  sporophyte  stage  and  a  haploid   mul▯cellular  stage  (gametophyte  stage)   •  Sporophyte  genera▯on  (diploid)   •  Produces  spores  as  a  result  of  meiosis   •  Only  diploid  organisms  can  produce  anything  by  meiosis   •  Spore  is  haploid  cell  that  becomes  gametophyte   •  Gametophyte  genera▯on  (haploid)   •  Mul▯cellular  individual  that  produces  gametes   •  Made  of  haploid  cells,  undergoes  mitosis  to  produce  egg  and  sperm   •  Egg  and  sperm  fuse  together  to  create  diploid  zygote   •  As  zygote  undergoes  mitosis  it  becomes  sporophyte   •  Moss  is  gametophyte  genera▯on   •  Gametophyte  genera▯on  present  in  all  plants,  just  smaller  in  some   •  Internalized  in  body  of  larger  plants   •  Flowering  plants,  ferns,  gymnosperms  characterized  as  sporophytes     3 •  Archegonium  and  Ovule   •  Prevent  egg  structure  from  drying  out   •  Xylem  -­‐  transports  water  from  roots  to  photosynthe▯c  places   •  Phloem  –  transports  nutrients  through  plant   •  Cu▯cle  helps  to  hold  water  in  leaf   •  Opening  and  closing  of  stomata  necessary  for  gas  exchange  (lets  carbon  dioxide  in  for   photosynthesis,  oxygen  out  as  product)   •  Important  adapta▯ons  for  life  in  terrestrial  environment   •  Nonvascular  Plants:   •  Without  transport  system,  all  are  small   •  Bryophytes  –  nonvascular  plants  that  lack  specialized  needs  of  transpor▯ng  water  and   nutrients   •  No  true  root,  stems,  or  leaves   •  No  xylem  or  phloem   •  Dominated  by  gametophyte  genera▯on  (body  of  plant)   •  Produce  eggs  in  protec▯ve  structure  (archegonia)   •  Water  needs  to  be  present  for  fer▯liza▯on  to  be  possible   •  Generally  reside  in  harsh  environments   •  *require  water  to  reproduce*   •  Rhizoids  –  branching,  root-­‐like  structure   •  provides  anchoring  surface   •  Dominated  by  gametophyte  genera▯on   •  Mosses:   •  Thrive  in  harsh  environments   •  Peat  bogs  –  hold  carbon  dioxide,  can  be  harvested  and  burned  as  energy  (fuel)  resource   •  Sphagnum  –  holds  a  large  amount  of  water   •  Mosses  are  an  indicator  species  –  do  not  grow  well  in  polluted  areas   •  Can  be  a  food  source,  lots  of  uses   •  Vascular  Plants:   •  Sporophyte  genera▯on   •  Xylem  –  transports  water  and  dissolved  minerals  up  roots,  through  stem,  and  to  leaves   •  Phloem  –  transports  organic  compounds  throughout  plant   •  Lignin  –  key  to  evolu▯on  of  trees   4 •  Seedless  Vascular  Plants:   •  True  transport  ▯ssues   •  Strobili:  where  spores  are  released  from  (alterna▯on  of  genera▯ons  -­‐>  sporophyte   and  gametophytes)   •  Leaves  are  extensions  of  the  stem  that  give  rise  to  branch  points   •  Microphylls:  one  strand  of  vascular  ▯ssue   •  Dominant  sporophyte  genera▯on   •  True  roots,  stems  leaves  present  because  they  have  true  vascular  ▯ssue   •  Water  is  s▯ll  required  in  order  to  produce  fer▯liza▯on   •  Wet,  marshy  environment     •  Expansion  of  vascular  ▯ssue  -­‐>  broad  leaves  with  several  strands  of  vascular  ▯ssue   (improving  transport  network)   •  Require  water  to  accomplish  fer▯liza▯on  -­‐>  sperm  travels  across  water  to  fer▯lize   female  part   •  Wet,  marshy  environment   •  Broad  leaves  primary  loca▯on  of  photosynthesis     •  Megaphylls:  broad  leaves  with  several  strands  of  vascular  ▯ssue   •  Strobilus:  where  spores  are  generated   •  ***megaphylls  key  -­‐>  lead  to  more  fit  organisms  (more  photosynthesis,  water,   food,  etc.)   •  need  wet  environment   •  Fronds:  where  megaphyll  ▯ssue  is  contained  in  leaves   •  Dominant  sporophyte  genera▯on   •  Spores  are  li▯le  red  dots  located  on  fern  frond   •  Sori:  where  spores  are  generated   •  Spores  become  gametophyte  genera▯on  when  in  right  environment  -­‐>  have  male   and  female  ▯ssue   •  Sporophyte  genera▯on  grows  on  gametophyte  genera▯on  (fiddlehead    
More Less

Related notes for BIOL 1113

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit