Answer:
A adaptation is the action or process of adapting or being adapted
Explanation:
is mostly when a animal is adapted to something.
This type of classification used to be used when classifying the protostome organisms.
In this type of organism, the oral cavity develops from the blastophore, the initial cavity in the gastrula, an early stage of the development of the embryo.
Answer:

Explanation:
An element only has <u>one</u> type of atom and cannot be broken down by chemical means.
Let's analyze the answer choices.
1. This has two types of atoms, so it cannot be an element. It has more than one type of atom.
2. This has two types of atoms that are bonded together. It cannot be an element because there is more than one type of atom and the bonds can be broken.
3. This has one type of atoms, so it is an element.
Therefore the best answer choice is 3.
I believe the correct answer to the question is D. This answer choice makes the most sense given the context. Also, since RNA is less stable than DNA, it mutates more often.