Tag: zoology

Questions Related to zoology

 A. Symmetry of ctenophorans  1. Haeckelia
 B. Ctenophora with nematocyst  2. Radial
 C. Habitat of comb jellies   3. Colloblast
 D. Specialised cells of comb jellies  4. Marine


  1. A- 3, B- 4, C- 2, D- 1

  2. A- 4, B- 3, C- 2, D- 1

  3. A- 1, B- 2, C- 3, D- 4

  4. A- 2, B- 1, C- 4, D- 3


Correct Option: D
Explanation:
The ctenophores have radial symmetry. They have elongated and tubular body. They are attached to the substratum by on end. The other end has an opening called as mouth which is surrounded by long tentacles. Thus, the symmetry of these organism are called as biradial symmetry. 
Species of Haeckelia are known to carry nematocysts on their medusae. They carry the nematocysts on their tentacles. There are nematocysts which are arranged on the medusae. 
Habitat of comb jellies is marine waters. They can survive in shallow waters as well as in depth. Some of the species are found near the water surface.
Specialised cells are present in comb jellies which are known as colloblasts. These are sticky type of cells and adhere to the prey. This helps in capturing the prey as these organisms lack the stinging cells. 
Thus, the correct answer is option D. 

The symmetry exhibited by comb jellies is

  1. Spherical Symmetry

  2. Bilateral symmetry

  3. Biradial symmetry

  4. None of the above


Correct Option: C
Explanation:

Ctenophore phylum which includes Comb jellies exhibit Biradial symmetry. It is when the organism can be divided up into equal parts, but with two planes only. Hence option C is correct.

Comb jellies are 

  1. Strong swimmers

  2. Phytoplanktons

  3. Planktonic animals

  4. None of the above


Correct Option: C
Explanation:

Comb jellies are not strong swimmers. They are typically planktonic animals, transparent and unpigmented and most swim by the synchronous beating of the eight rows of comb plates. Hence, option C is correct.

Why does the Ctenophora is a minor phylum?

  1. It includes small sized animals.

  2. It includes only few genera.

  3. It does not includes animals of economic importance.

  4. It was included earlier in Cnidaria.


Correct Option: B
Explanation:

Ctenophora is considered as a small phylum. The phylum contains very few genera and only about 80 species. This group includes a set of marine animals. These organisms are commonly called as comb jellies. Earlier, this phylum was placed under Coelenterata. Hatschek placed it under a separate phylum. 

Thus, the correct answer is option B. 

Biradial symmetry and lack of cnidoblasts are the characteristic of 

  1. Hydra and starfish

  2. Starfish and sea anemone

  3. Ctenoplana and Beroe

  4. Aurelia and Paramoecium


Correct Option: C
Explanation:

Biradial symmetry and lack of cnidoblasts are characteristics of phylum Ctenophora. They have adhesive structure, known as coloblasts instead of cnidoblasts. Both Ctenoplana and Beroe are ctenophores. Hence, option C is correct.

Ctenophores have the following symmetry

  1. Spherical

  2. Pentaradial

  3. Biradial

  4. All of the above


Correct Option: C
Explanation:

The ctenophores are diploblastic with a biradial symmetry or modified radial  (with an underlying bilateral symmetry), which is a bit different than the radial symmetry typical of cnidarian.

A radially symmetrical free swimming bioluminescent diploblastic marine organism is

  1. Sea Fan

  2. Sea Pen

  3. Sea Walnut

  4. Bath sponge


Correct Option: C

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