Which of the following is not necessary for designation as a chordate?

I. A notochord

II. Vertebrae

III. A post-anal tail

IV. Gill arches

V. A dorsal, tubular nervous system

Which of the following statements about chordates is true?

Which of the following organelles is/are mainly present in animal cells?

I. Peroxisome

II. Centrioles

III. Flagella