Which of the following is NOT a characteristic feature of Porifera?
Presence of choanocytes
Presence of a true coelom
Body supported by spicules or spongin fibres
Mostly marine, asymmetrical body
Related Questions
The larval stage in sponges is distinct from the adult form. This type of development is known as:
Direct development
Asexual reproduction
Regeneration
Indirect development
Which of these is referred to as ‘Venus flower basket’?
Spongilla
Sycon
Euplectella
Cliona
From the following statements select the wrong one.
Millipeds have two pairs of appendages in each segment of the body
Prawn has two pairs of antennae
Animals belonging to phylum-Porifera are exclusively marine
Nematocysts are characteristic of the phylum-Cnidaria
Which type of cells absent in sponges?
Trophocytes
Myocytes
Archaeocytes
Cnidocytes
Sponges primarily reproduce asexually by:
Binary fission
Budding and gemmule formation
Fragmentation only
Spore formation
Which of the following is a freshwater sponge?
Sycon
Spongilla
Euplectella
Hyalonema
Explain the evolutionary significance of the presence of cellular layers in Porifera despite their lack of true tissues. How does this relate to the potential for more complex body plans in other animal phyla?
The cellular layers in Porifera are analogous to plant tissues, suggesting a common ancestor.
The lack of true tissues limits their complexity, preventing further evolutionary development.
The cellular layers are simply an artifact of their aquatic environment and have no evolutionary significance.
The distinct cell layers, though not forming true tissues, represent a step towards tissue-level organization, foreshadowing the more complex tissue development observed in Eumetazoa.
The central cavity in the body of a sponge is called:
Osculum
Spongocoel
Ostia
Gastrovascular cavity
Which one of the following statements about all the four of Spongilla, leech, dolphin and penguin is correct?
Penguin is homeothermic, while the remaining three are poikilothermic
Leech is a fresh water form, while all others are marine
Spongilla has special collar cells called choanocytes, which are not found in the remaining three
All are bilaterally symmetrical animals
Water circulation in sponges does not help in
Locomotion
Food gathering
Respiration
Removal of waste
