Tag: phylum ctenophora

Questions Related to phylum ctenophora

Tentacles are absent in

  1. Beroe

  2. Ctenoplana

  3. Hormiphora

  4. Obelia


Correct Option: A
Explanation:

Boroe is a type of comb jelly and has a body structure that is transparent and sac like with a mouth at one end. The gastrovascular channels are beneath the cilia and the animal lacks any tentacles otherwise. So, the correct answer is 'Boroe.

Comb jellies belong to the phylum

  1. Ciliophora

  2. Coelenterata

  3. Porifera

  4. Ctenophora


Correct Option: D
Explanation:

Comb jellies are oval-shaped animals with eight rows of tiny comb-like plates that they beat to move through the water.  They are gelatinous animals belonging to the phylum of animals that live in marine waters worldwide, ctenophora.
Thus, the correct answer is option D.

Select the taxon whose members live exclusively in marine water.

  1. Annelida

  2. Ctenophore

  3. Arthropoda

  4. Mollusca


Correct Option: A

Ctenophores exhibits

  1. Bioluminescence

  2. Metagenesis

  3. Parthenogenesis

  4. Metamerism


Correct Option: A
Explanation:

Ctenophores, also called the comb-jellies, exhibit bioluminescence. The enzyme called photoprotein is present in them in which luciferin is combined with oxygen. When the calcium changes the shape of the ptotoprotein, light is given off.

Hence, the correct answer is 'Bioluminescence'  

Intermediate between diploblastic and triploblastic body structure is found in

  1. Porifers

  2. Coelenterates

  3. Ctenophores

  4. Platyhelminthes


Correct Option: C
Explanation:

Some animals are three layered with ectoderm, endoderm and mesoderm called triploblastic.  Ctenophores have two main layers of cells that sandwich a middle layer of jelly-like material, which is called the mesoglea. So, even though the layers of tisse are diploblastic the presence of the third jelly-like layer gives them an intermediate stage.

So, the correct answer is 'Ctenophores'.

Which is absent in ctenophores?

  1. Epidermis

  2. Intercellular and intracellular digestion

  3. Cnidoblasts

  4. Medusa phase.


Correct Option: C
Explanation:

Ctenophores have colloblast in their tentacles to capture/ disarm their prey as opposed to cnidarians like jelly fish having Cnidoblasts doing the same function.

So, the correct answer is 'Cnidoblasts'.

What is present in mesoglea of ctenophores which makes it a loose layer of cells?

  1. Amoebocytes

  2. Elastic cells

  3. Nerve cells and muscle cells

  4. All the above


Correct Option: D
Explanation:

The loose layer of jelly-like substance in Ctenophores is mesoglea which are composed of muscle bundles and nerve fibres that lie under the epethelial cells. They are hydrostatic and have elastic cells along with amoebocytes that have a role in phagocytosis, 

So, the correct answer is 'All the above'.

Comb plates are found in ____________.

  1. Adamsia

  2. Aurelia

  3. Nereis

  4. Pleurobrachia


Correct Option: D

Biradial symmetry and lack of cnidoblasts are characteristics of

  1. Hydra and Starfish

  2. Starfish and Sea Anemone

  3. Ctenoplana/Ctenophora and Beroe

  4. Aurelia and Paramecium


Correct Option: C
Explanation:

Biradial symmetry is a combination of radial and bilateral symmetry, as in the ctenophores. Here, the body components are arranged with similar parts on either side of a central axis, and each of the four sides of the body is identical to the opposite side but different from the adjacent side. Also, Cnidblasts being exclusive Cnidarian character does not exist in Ctenophora.

So, the correct answer is 'Ctenoplana and Boroe'.

Anal pores occur in gastrovascular system of

  1. Physalia

  2. Corals

  3. Aurelia

  4. Ctenophores


Correct Option: D
Explanation:

In Ctenophores, the digestion is predominantly completed in the stomadaeum(extracellular). The undigested food passes out either throught the mouth or the anal pores. 

So, the correct answer is 'Ctenophores'.