I believe the answer is Planet Nine.
Advantage: Dichotomous keys are very useful because they allow non-expert users to identify organisms by directing them to look at the known, important organisms. Disadvantage: Disadvantage of dichotomous keys is that if a single wrong decision is made at any juncture, a wrong identification will result. Sometimes it becomes obvious that an error has been made, and you can retrace your steps until you get back on the right track, but this is not always the case
Mutualism is where both animal help each other to benefit form each other. Win-Win . Commensalism is where nothing happen neither animal benefits from it .
Calcium is few of the main sources for healthy bones, teeth, and muscles.
