Question

write a short note about porifera​

Answer 1

${ \star{ \boxed{ \pink{ \mathtt{Porifera}}}}}{ \star}$

Phylum Porifera consist if of primitive invertebrate animals comprising the sponges

${ \bf{ \underline{Characters}}}$

⭥ The cells of Poriferans are loosely organized.

⭥ They are mostly found in marine water. Only a few are found in freshwater.

⭥ They are either radially symmetrical or asymmetrical.

⭥ Their body is usually cylindrical.

⭥ The scleroblast secretes spicules while spongin fibres are secreted by spongioblasts.

⭥ They have no organs in their body.

⭥ They depict cellular grade of organization.

⭥ The body is comprised of numerous pores known as Ostia and osculum.

⭥ The central cavity is called spongocoel or atrium which open outside through the osculum.

⭥ They reproduce asexually by budding, and fragmentation.

⭥ The nutrition is holozoic.

⭥ They have neurosensory cells but are devoid of any specific nervous system.

____________________________________________________

${ \bf{ Explore \: More:-}}$

➟ Poriferans don't have mouths; instead, they have tiny pores in their outer walls through which water is drawn.

➟ They have the power to regenerate the lost parts.

➟ The development is indirect and the cleavage is holoblastic.

____________________________________________________