Question

12 according to the cladogram below, what two characteristics do crabs and barnacles share that limpets do not?appendagesconical shellscrustaceansgastropodcrabbarnaclelimpetcrabbarnaclelimpetmolted external skeletonsegmentationtiny free-swimminglarvaaba molted external skeleton and segmentationb conical shells and gastropodc appendages and conical shellsd tiny free-swimming larva and segmentation

Explanation:

1. Analyze cladogram B: The trait "tiny free-swimming larva" is shared by all three organisms, so it is not unique to crabs and barnacles.
2. The traits "molted external skeleton" and "segmentation" are marked on the branch leading only to crabs and barnacles, meaning these are shared by them but not by limpets.
3. Eliminate other options: Option B includes "gastropod" which only applies to limpets; Option C includes "conical shells" which limpets have; Option D includes the shared larva trait.

Answer:

A. Molted external skeleton and segmentation