A scientist is studying some developing eggs from an ocean sample. The early embryos have divided only a few times, and all cells look identical. When the scientist carefully removes half the cells from an embryo, both clumps of cells are able to complete development, forming twins. The eggs can be identified as cnidarians. crustaceans. protostomes. deuterostomes. echinoderms.

Which best describes the digestive system of arthropods? a incomplete, two openings b complete, one opening c two-way, one opening d one-way, two openings

The fish shown above is a tarpon. it is a fast-swimming and powerful open-water fish. its closest relatives, oddly, are burrow-dwelling conger eels that stay on the bottom. both eels and tarpon developed from snake-like larvae that float in the plankton during the first stages of life. once they mature, tarpon and eels are not found near one another in the ocean. the tarpon and the eel illustrate all of the following except

One of the purposes of transcription is to produce a sequence of bases that