Invertebrate Zoology | MCQs

Explanation

The invertebrate that has a water vascular system is an echinoderm

Specifically starfish, sea urchins, sea cucumbers, brittle stars, and feather stars.

This unique system is a defining characteristic of the phylum Echinodermata. 

Explanation

Annelids do have a closed circulatory system, along with other invertebrates and vertebrates

Annelids, like earthworms, have a closed circulatory system.

In annelids, blood is pumped along by muscles in blood vessels.

The blood picks up food molecules from the digestive tract and oxygen from the skin.

It then transports these to the cells of the body. 

Explanation

Mesohyl is a gelatinous, protein-rich layer found in sponges, acting as a connective tissue between their inner and outer layers.

Explanation

The body is covered by a glandular epithelial envelope called a mantle

They secrete a calcareous shell

Explanation

Actinopods are a group of protists that use specialized pseudopodia, called axopodia, for locomotion and capturing food. 

Explanation

Explanation

Planaria has a diffused nervous system.

Planarians, which are flatworms belonging to the genus Planaria, have a primitive nervous system known as a diffused nerve net.

This nerve net is spread throughout the body and lacks the centralized organization found in more complex nervous systems.

Despite its simplicity, this nervous system allows planarians to exhibit basic behaviors such as:

• movement
• feeding
• response to stimuli
• 
  

Explanation

Porifera is the phylum of sponges, which are multicellular organisms characterized by their porous bodies.

Spongilla is a genus of freshwater sponges, and like all sponges, it belongs to the phylum Porifera.

These organisms are filter feeders, drawing in water through their pores to extract nutrients.

Explanation

Ancylostoma:

A genus of hookworms, which are parasitic nematodes (roundworms)

They belong to the phylum Nematoda, not Platyhelminthes.

Explanation

Protonephridia or flame cells are the excretory structures in Platyhelminthes (Flatworms, e.g., Planaria), rotifers, some annelids