Question

Members of the phylum Arthropoda lack which of the following features?

• A. External skeleton made of chitin
• B. Compound eyes
• C. Excretion by Malpighian tubules
• D. Usually a closed type of blood vascular system

Answer 1

The correct option is D Usually a closed type of blood vascular system

• Arthropoda includes invertebrate animals having a chitinous exoskeleton, a segmented body, jointed appendages and compound eyes. The excretory system consists of the Malpighian tubule.
• However, they have an open circulatory system. In the open circulatory system, the blood flows through open spaces at a slow velocity. They lack capillary systems and the fluid flowing in this system is called hemolymph. In the closed type of circulatory system, the blood flows through closed vessels at a very high velocity.

Therefore, the correct answer is option D.