Chapter 26, Problem 17A

Summary Introduction

Introduction :

Arthropods are grouped into classes based on common characteristics, such as body segment form, appendages and mouthparts. The naming of arthropods is still questioned by taxonomists. Arthropods have joint-appended exoskeletons that allow them to move in diverse ways.

Answer to Problem 17A

Correct answer :

The correct answer is option (C) spider

Explanation of Solution

Explanation/justification for the correct answer :

Option (C) spider. Spider has two parts of the body: a cephalothorax and an abdomen, which both have six pairs of attachments. They have no antennas. The chelicerae are designed to act as pincers, and are sometimes attached to a gland with poison. So, the correct answer is option (C).

Explanation for incorrect answer :

Option (A) tick. Ticks are parasites that suck on blood after they are attached to their hosts' surface. They possess cephalothorax and fused abdomen into one oval portion of the body. So, this is an incorrect answer.

Option (B) scorpion. Scorpion possesses cephalothorax and abdomen fused into one part of an oval-shaped body. Scorpion preys on insects and other small vertebrates that they catch and smash apart with their chelicerae. So, this is an incorrect answer.

Option (D) lobster. Lobsters have chelipeds which aid them to capture food and smash it. Even they have antennas in their bodies. So, this is an incorrect answer.