Question

Coxal glands are the excretory organs of
A. Crayfish
B. Devilfish
C. Jellyfish
D. Arachnid

Answer 1

Hint: Coxal glands are present in some of the organisms that belong to the phylum Arthropoda. The largest phylum in kingdom Animalia is the Arthropoda. The term Arthropoda imply jointed appendages. Arthropoda consists of organisms that have their body covered by a chitinous exoskeleton.

Complete answer: Arachnida is a class that belongs to the phylum Arthropoda. These animals excrete their waste materials with the help of coxal glands. These glands contain a sac that helps for the collection and storage of waste materials. These glands are often seen in pairs. The pore through which the urine passes out from the collecting sac is known as coxa. Arachnida includes organisms like spiders, scorpions, mites, ticks, etc. Animals in the phylum Arthropoda have jointed appendages. This phylum includes the class Insecta which are the animals with three pairs of legs. Sensory organs of these organisms include eyes, antennae and statocysts. Examples of insects are beetles, fly, dragonfly, cockroach etc. The chitinous exoskeleton of arthropods can be periodically removed and renewed. This process is known as moulting or ecdysis. The moulting helps in the growth and expansion of the body of these organisms. The exoskeleton made up of ‘chitin’ also contains certain proteins and is hardened due to the presence of calcium carbonate and calcium phosphate.
Hence, the correct answer is option D.

Note: Arachinada belongs to a group of organisms called Chelicerata, which is a subphylum under the phylum Arthropoda. Phylum Arthropoda also includes insects which are the group of animals with 8 legs. The Insecta is the largest class in the animal kingdom.