A)separate male and female individuals. B)a larval stage that lacks sense organs. C)a coelom but there is no peritoneum lining. D)spiral and unequal cleavage. E)a coelom formed from the archenteron extending backward,not from pinched off coelomic sacs.
Treating sea urchin eggs with hypertonic seawater or subjecting them to other stimuli causes them to develop without the presence of sperm,a phenomenon called
A)on plankton and small fish. B)by retracting a hood and snapping onto food items. C)by surfacing at night and drifting transparently among plankton. D)All of the choices are correct. E)None of the choices is correct.