Which characteristics do all bony and jawless fish have in common? Check all that apply. backbone
swim bladder
scales
gills
bony skeleton

this is the last time im doing this. ANSWER WITH MORE THAN ONE OPTION, DO NOT COPY PASTE FROM G00GLE, DO NOT PUT VIRUS LINKS, THANK YOU.

gills

Explanation: A fish without a jaw was the first vertebrate to evolve. These fish used filtration to capture their food and sucked water and debris from the sea through their mouths and then released the water and trash through their gills. Some features are as follows:

1. They have a notocorda that serves as support through the back of the fish.

2. Gill bags. These organs are responsible for filtering the oxygen in the water.

3. A pineal eye that is sensitive to light

4. A cartilaginous skeleton

All except backbone i think

The main use of litmus is to test whether a solution is acidic or basic. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F).