Top Posters
Since Sunday
g
2
1
1
1
1
Home Gallery Plant Biology
Explore Categories
  
SlideshowReport

Hypothetical stages in the evolution of seeds.
Download Without Watermark With Free Membership
Description
The parallel evolution of heterospory and endosporic gametophytes in some lycophytes and pteridophytes, as well as the seed plants, suggests that these features were acquired early in the evolution of seeds. Later-occurring events in the origin of seeds were the reduction in the number of megaspores to one per megasporangium and the enclosure of the megasporangium by protective, leaflike integuments.
Related Images
 8011
 1184
 1013
 365
 917
 1098
 1114
 7715
 224
 1215
Add Comment
Explore
Post your homework questions and get free online help from our incredible volunteers
  670 People Browsing
 116 Signed Up Today
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Show Emoticons
:):(;):P:D:|:O:?:nerd:8o:glasses::-):-(:-*O:-D>:-D:o):idea::important::help::error::warning::favorite:
Your Opinion
Which industry do you think artificial intelligence (AI) will impact the most?
Votes: 756
Previous poll results: Which country would you like to visit for its food?