Which of the following organisms is a deuterostome that exhibits bilateral symmetry and cephalization?

Me how do you name a compound with more than two elements?

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

Which of the following describes a difference when gram-positive bacteria are compared to gram-negative bacteria?