Arthropods: Structure and Function

Arthropods are a diverse and successful group of animals found in various habitats worldwide. They have a segmented body with a hard exoskeleton made of chitin, which they shed during growth. Their body structure includes a head and trunk, with some species having a cephalothorax. Arthropods possess an open circulatory system with a haemocele and have different respiratory organs depending on their habitat. Excretion occurs through coelomoducts or malpugin tubules, and they have a well-developed nervous system similar to annelids.

What is a unique feature of arthropods that contributes to their biological success?

• They are found only in aquatic environments.

• They have a soft body structure.

• They lack a nervous system.

• They have a segmented body with bilateral symmetry.

In some arthropods like crabs, what is the body division called when the thorax fuses with the head?

• Cephalothorax

• Abdominocephalus

• Thoracocephalus

• Headtrunk

What is the primary component of the arthropod exoskeleton?

• Chitin

• Keratin

• Silica

• Calcium carbonate

How do arthropods circulate blood within their bodies?

• Using a network of capillaries

• Through a closed circulatory system

• By diffusion through the skin

• Via an open circulatory system with a haemocele

Which respiratory structures are found in terrestrial arthropods?

• Skin

• Trachea or book lungs

• Lungs

• Gills

What is a characteristic of the arthropod nervous system?

• It includes a cerebral ganglion and ventral nerve cord.

• It is undeveloped and simple.

• It lacks a cerebral ganglion.

• It is similar to that of mammals.