Table of Contents
What type of skeleton do Porifera have?
Sponge skeletons are made of rod-like silica structures called spicules that are cemented to rocks and to each other with collagen.
What is the body wall of Porifera?
The body wall of a sponge i.e. Porifera consists of two layers, the outer layer is called pinacoderm and the inner layer is called choanoderm, with non-cellular mesenchyme in between. It is the interconnecting proteinaceous gelatinous matrix.
What are the 3 classes of phylum Porifera?
The three main classes of the phylum Porifera are Hexactinellida, Calcarea and Demospongia.
Is Porifera exoskeleton or endoskeleton?
Sponges are aquatic invertebrates. They make up the phylum Porifera. Sponges have specialized cells and an endoskeleton. They lack tissues and body symmetry.
What forms the skeleton in sponges?
The mineral skeleton is formed for the most part by units called spicules, either scattered throughout the sponge or united to form fibres; spicules are classified as megascleres, which function in support, and microscleres, which function in protection and also aid in support.
What is skeleton and types of skeleton?
A skeleton is a structural frame that supports an animal body. There are several different skeletal types: the exoskeleton, which is the stable outer shell of an organism, the endoskeleton, which forms the support structure inside the body, and the hydroskeleton, a flexible skeleton supported by fluid pressure.
Is the middle layer of the body wall of porifera?
So, the correct answer is ‘Mesoglea’.
Do sponges have cell walls?
Sponges are similar to other animals in that they are multicellular, heterotrophic, lack cell walls and produce sperm cells. Unlike other animals, they lack true tissues and organs.
What are the four classes of sponges?
The classification of sponges is based on spicule form and chemical composition. Living sponges have traditionally been divided into three or perhaps four classes: Homoscleromorpha, Calcispongiae, Hexactinellida, and Demospongiae.
What are the skeletal material of sponges?
What do you mean by endoskeleton of Porifera?
The poriferan “skeleton” consists of microscopic calcareous or siliceous spicules or a spongin network. The Coleoidae do not have a true endoskeleton in the evolutionary sense; there, a mollusk exoskeleton evolved into several sorts of internal structure, the “cuttlebone” of cuttlefish being the best-known version.
Is Porifera have exoskeleton?
Answer and Explanation: Technically, sponges do not have exoskeletons or endoskeletons as they are completely made of soft material.
What are 3 types of spicules in Porifera?
Based on the number of axis present in the rays spicules may be of three types: monoaxon, triaxon and polyaxon.
What are the 2 types of skeletons?
The adult human skeleton usually consists of 206 named bones. These bones can be grouped in two divisions: axial skeleton and appendicular skeleton. The 80 bones of the axial skeleton form the vertical axis of the body.
What is Crown sponge?
Scypha, also known as crown sponge, is a small, marine sponge found attached by a sticky secretion to some submerged solid object like rocks, shells of molluscs and corals.
What is mesohyl sponge?
Mesohyl is an extracellular matrix consisting of a collagen -like gel with suspended cells that perform various functions. The gel-like consistency of mesohyl acts as an endoskeleton, maintaining the tubular morphology of sponges.
Do sponges have bones?
Sponges, like all animals, possess some sort of a skeleton that gives their bodies shape. As a whole, poriferans have diverse skeletal elements including calcareous laminae, organic filaments, and siliceous and calcareous spicules.
What kind of body structure does a sponge have?
A sponge’s body is hollow and is held in shape by the mesohyl, a jelly-like substance made mainly of collagen and reinforced by a dense network of fibers also made of collagen. The inner surface is covered with choanocytes, cells with cylindrical or conical collars surrounding one flagellum per choanocyte.