frogs,toads,snakes,lizards
Seminiferous tubles is the only part of a male reproductive system
-Presence of jointed appendages and gills, lungs, jaws.
-Presence of a chitinous external skeleton or exoskeleton that change periodically.
-Body constituted by repetitive segments, phenomenon known as metamerism<span>.</span>
<span>I hope this help,</span>
<span> Sebastian Goicoechea.</span>
Answer:
A scientific hypothesis must be testable, and;
A scientific hypothesis must be falsifiable.
Explanation:
I looked it up o-o sorry if its wrong. :3
The primary difficulty is the fact that we do not know all of the organisms that currently exist in the world along with those that existed in the past.