Chapter 26, Problem 16A

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 16A

Correct answer :

The correct answer is option (D) antennae

Explanation of Solution

Explanation/justification for the correct answer :

Option (D) antennae. Crustaceans live in aquatic habitats. They also have two antennae pairs. Arachnids have no antennae. They have pedipalps that can detect and hold prey. So, the correct answer is option (D).

Explanation for incorrect answer :

Option (A) chelicerae. The most anterior pair of appendages of an arachnid is changed to mouthparts called chelicerae. So, this is an incorrect answer.

Option (B) pedipalps. Arachnids have a pair of appendages called pedipalps that are used to identify and retain prey. So, this is an incorrect answer.

Option (C) spinnerets. The silken spider webs are made from a fluid protein that is synthesized by the glands and spun into silk by structures known spinnerets at the end of the abdomen of a spider. So, this is an incorrect answer.