Q1) Class Crustacea have following features:
A. Cephalothorax, biramous appendages, gills
B. Head and thorax, book lungs, chitinous exoskeleton
C. Head and thorax, biramous appendages, book lungs
D. Cephalothorax, book lungs, chitinous exoskeleton
NOTEImportant Question from
AIIMS
See Answer and Explanation Here
Answer: A. Cephalothorax, biramous appendages, gills
Explanation:
Class Crustacea
• Mainly aquatic, generally marine but few freshwater and few live in moist places.
• Free living but few are parasitic forms
• Head often fused with thorax to form cephalothorax covered dorsally by carapace.
• Head bears a pair of compound eyes and five pairs of appendages.
• Thorax and abdomen often with a pair of biramous appendages in each segment; appendages modified for various purpose.
• Respiration either by gills or general body surface.
• Coelom greatly reduced, it is in the form of haemocoel.
• Blood vascular system comprises a dorsal contractile heart communicating by valvular ostia with an enclosing pericardial sinus.
• Excretory organs are modified coelomoducts which may be either maxillary glands or antennary (green) glands.
• Sexes usually separate; sexual dimorphism is common.
• Development includes metamorphosis with free larval stages.
Examples: Streptocephalus, Daphnia, Mysis, palaemon
Reference: Invertibrate Zoology By P.S.Verma, Page no: 733 & Animal Kingdom By D. Bhaskara Rao, Page no: 61.