9.16: Arachnids Difficulty Level: At Grade Created by: CK-12 CK-12 Life Science Concepts For Middle School Invertebrates % Progress Practice Arachnids Practice Progress % Practice Now Read Practice Resources Details Loading... Vocabulary Language: English ▼ English arachnid arachnidClass of arthropods having four pairs of legs which includes the spiders, scorpions, and ticks. cephalothorax cephalothoraxFusion of the head and thorax. chelicerae cheliceraeFanglike appendages near the mouth that serve in feeding and defense. diurnal diurnalActive in the daytime. nocturnal nocturnalActive at night. pedipalps pedipalpsAppendages near the mouth that are modified for reproduction, catching prey, and other functions. silk silkThreads spun by spiders to make webs, enclose their eggs, and to serve other functions. Image Attributions Description Covers the characteristics and subgroups of arachnids. Learning Objectives None Difficulty Level: At Grade Authors: Jessica Harwood Douglas Wilkin, Ph.D. Contributors: Doris Kraus, Ph.D. Niamh Gray-Wilson Jean Brainard, Ph.D. Sarah Johnson Jane Willan Corliss Karasov Editors: Douglas Wilkin, Ph.D. Tags: arachnids cephalothorax chelicerae (4 more) pedipalps SCI.BIO.825.3.L.1 SCI.LSC.825.3.L.1 silk Subjects: science Life Science Concept Nodes: SCI.LSC.825.3 (Arachnids) Grades: 7 , 8 Date Created: Nov 29, 2012 Last Modified: May 05, 2015 Vocabulary None You can only attach files to Modality which belong to you If you would like to associate files with this Modality, please make a copy first.