Which of the following would rank lowest in cephalization? a. arthropods b. mammals c. mollusks d. cnidarians

The correct answer is- D) Cnidarians.

Cephalisation is a process that describes the development of a distinct head that possesses a well developed brain, which controls the whole body of the organism. Vertebrates like mammals are the most cephalised organisms as they contain highly developed head with nervous system.    

Among invertebrates, some cephalised organisms include insects, spiders, mites ( that come under arthropoda).

Cnidarians like sea anemone, jelly fish are lowest in cephalisation because they only contain a basic nervous system but they are devoid of head.                

answer; 60-100; beats per minute

the major parts of the digestive system:

salivary glands.

pharynx.

esophagus.

stomach.

small intestine.

large intestine.

rectum.

accessory digestive organs: liver, gallbladder, pancreas.