The answer is a simple radial nervous system.
Echinoderms do not have brains. Around their mouth, they have central rings from which nerves radially run into arms and along the body. Movement is controlled by the branches of those radial nerves.
Answer:
you can't see sickle cell in a karyotype a it is inside one of the chromosomes
it is a single gene disorder
Explanation:
The answer to your question is,
D. Adhesion
-Mabel <3
