The is a microtubule structure that binds to sister chromatids to separate them in anaphase

List the advantages and disadavantages of the switch from persistent chlorinated hydrocarbon pesticides (such as ddt) to nonpersistent organophosphate pesicides. have the benefits of the switch outweighed the disadvantages? explain.

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

Sea stars, sea urchins, sand dollars, and brittle stars are all memeber of a group, what is the common name of the group they are all in