During metamorphosis, echinoderms undergo a transformation from motile larvae to a sedentary (or sometimes sessile) existence as adults. What differentiates echinoderm adults, but not their larvae? Adults should
A) lack mesodermally derived tissues.
B) have radial symmetry, or something close to it.
C) be diploblastic.
D) A and B only
E) A, B, and C

Forces that are equal in strength but opposite in direction are a.) balanced b.) unbalanced c.) always result in motion d.) do not exist

The organelle pictured is found in cells of and is theorized to have once been an independent organism.

The blue particles in this image are able to cross the cell membrane through simple diffusion. how will they be transported? outside the cell inside the cell o a. the substances will move directly across the membrane from outside the cell to inside the cell. b. the substances will move through channels in the membrane proteins from outside the cell to inside the cell. o c. the substances will move through channels in the membrane proteins from inside the cell to outside the cell. o d. the substances will move directly across the membrane from inside the cell to outside the cell.