True.
A dichotomous key breaks down an organisms characteristics until you can fully identify it.
Answer:
Scientists usually use the potassium-argon method to date rocks that are older than about 1 million years. Uranium-238 is also used for radiometric dating. It has a half-life of 4.5 billion years. It decays to produce lead-206.
Answer:
1. Either porifera or asymmetrical
2. Invertebrate
3. filtering
4. Axis
5. I don't know this one, I'm sorry.
6. Exoskeleton
7. Cold-Blooded creature
8. Vertebrate
9. Endoskeleton
10. Warm-blooded animal
Good Luck! Hope I wasn't too late.
