Class 9 - Biology - Diversity in Living Organisms - PHYLUM-PORIFERA

Описание: #Biology #Diversity in Living Organisms #Phylum-porifera #Asymmetry #Radial Symmetry #Ingestion of food #Spicules #Diffusion #turito

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Phylum Porifera:
Phylum Porifera refers to a diverse group of aquatic animals commonly known as sponges. Sponges are simple, multicellular organisms that lack true tissues and organs. They are considered one of the earliest forms of multicellular life and are primarily marine, although some species inhabit freshwater environments. Porifera comes from the Latin words "porus" (pore) and "ferre" (to bear), reflecting the characteristic pore-bearing structure of sponges.

Characteristics of Phylum Porifera:

Cellular Organization: Sponges exhibit cellular-level organization, lacking true tissues and organs. They are composed of specialized cells that perform specific functions.

Skeletal Structure: Sponges possess a unique skeletal structure made of microscopic needle-like structures called spicules, which may be composed of calcium carbonate, silica, or a flexible protein called spongin.

Body Openings: The body of a sponge is perforated with numerous pores, including inhalant pores (ostia) through which water enters, and a larger opening (osculum) through which water exits after passing through internal chambers.

Filter Feeding: Sponges are filter feeders, actively pumping water through their bodies to extract microscopic organisms and organic particles for nutrition.

Asexual Reproduction: Sponges can reproduce asexually through processes such as fragmentation, where a piece of the sponge can grow into a new individual.

Regeneration: Sponges exhibit remarkable regenerative abilities, with some species capable of regrowing from fragments.

Lack of Nervous System: Sponges lack a nervous system and true muscles, relying on the coordinated action of specialized cells for movement and feeding.

Habitats: While most sponges are marine, some species can be found in freshwater environments. They inhabit a variety of locations, from shallow coastal waters to deep-sea environments.

The phylum Porifera represents a crucial evolutionary step in the development of multicellular animals. Despite their seemingly simple structure, sponges play important ecological roles in marine ecosystems and contribute to nutrient cycling.