In an eight-cell embryo of an organism, the cells of the upper tier are aligned directly over the cells of the lower tier. Which organism is it likely to be?. A) earthworm. B) snail. C) starfish
I think the correct answer among the choices listed above is option C. The organism described most likely is a starfish. This is because annelids and mollusks exhibit spiral holoblastic cleavage while the echinoderms have radial holoblastic cleavage.