× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
5
a
5
k
5
c
5
B
5
l
5
C
4
s
4
a
4
t
4
i
4
r
4
Home Q & A Board Biology-Related Homework Help General Biology
New Topic  
Moe.S Moe.S
wrote...
Go to Answer
Posts: 455
Rep: 0 0
6 years ago
These images show examples of
  1.jawless fish
  2.cartilaginous fish
  3.bony fish
  4.ray-finned fish
 
Question 2

Jaws evolved during the Silurian period by modification of _____ in a jawless ancestor.
  1.the cartilaginous skeleton
  2.the second pair of gill arches
  3.gill slit support structures
  4.the spiracle
Read 89 times
2 Replies
Replies
Answer verified by a subject expert
grodriguezzgrodriguezz
wrote...
#1
Top Poster
Posts: 529
Rep: 0 0
6 years ago
Sign in or Sign up in seconds to unlock everything for free
1

Related Topics

Moe.S Author
wrote...
#2
6 years ago
I just wanted to write to say thanks a bunch for the answer!
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1311 People Browsing
 104 Signed Up Today
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 27
  
 282
  
 337
Your Opinion
Where do you get your textbooks?
Votes: 372
Previous poll results: Do you trust social media networks with protecting your privacy?