Porifera, Coelenterata and Ctenophora MCQ Quiz - Objective Question with Answer for Porifera, Coelenterata and Ctenophora - Download Free PDF

The correct answer is A: Aurelia, B: Adamsia

Explanation:

• A is Aurelia and B is Adamsia

Characteristics of Coelentrata:

• Coelentrata are aquatic,mostly marine,sessile or free swimming,radially symmetrical animals.
• Cnidoblasts are used for anchorage, defense and for the capture of prey Cnidarians exhibit tissue level of organisation and are diploblastic.
• They have a central gastro-vascular cavity with a single opening, mouth on hypostome.
• Digestion is extracellular and intracellular.
• Some of the cnidarians, e.g., corals have a skeleton composed of calcium carbonate.
• Cnidarians exhibit two basic body forms called polyp and medusa.
• Polyp is a sessile and cylindrical form like Hydra, Adamsia, etc. whereas, Medusa is umbrella-shaped and free-swimming like Aurelia or jelly fish.
• Those cnidarians which exist in both forms exhibit alternation of generation (Metagenesis), i.e., polyps produce medusae asexually and medusae form the polyps sexually (e.g., Obelia).
• Examples: Physalia (Portuguese man-of-war), Adamsia (Sea anemone), Pennatula (Sea-pen), Gorgonia (Sea-fan) and Meandrina (Brain coral).

The correct answer is Two

Explanation:

1. Cnidarians are freshwater animals: This statement is incorrect. Cnidarians are aquatic, mostly marine, sessile or free-swimming, radially
   symmetrical animals
2. Cnidarians have a complete digestive system with separate mouth and anus: This statement is incorrect. Cnidarians have an incomplete digestive system with a single opening that serves as both mouth and anus.
3. Digestion in Cnidarians is extracellular only: This statement is incorrect. Digestion in cnidarians is both extracellular (in the gastrovascular cavity) and intracellular (within the cells lining the cavity).
4. Cnidarians have a gastrovascular cavity with a single opening: This statement is correct. Cnidarians have a gastrovascular cavity that functions as both a digestive and circulatory system, with a single opening.
5. Obelia exhibits Metagenesis: This statement is correct. Obelia (a genus of jellyfish) exhibits metagenesis, alternating between asexual polyp and sexual medusa forms.
6. The medusa form is sessile and usually attached to the substrate: This statement is incorrect. The medusa form is free-swimming, while the polyp form is typically sessile.

The correct answer is Adamsia

Explanation:

• The given diagram indicates Polyp body from
• Adamsia exhibits Polyp body form
• Coelenterates have two basic body forms (Dimorphic)- polyp and medusa.
• Polyp is a sessile and cylindrical form like Hydra, Adamsia, etc. whereas, Medusa is umbrella-shaped and free-swimming like Aurelia or jelly fish.

Polyp	Medusa
Cylindrical in shape like a hydra, adamsia, etc.	Umbrella shaped like Aurelia
Mostly sessile	Free swimming
Asexual form	Sexual form
Example: Adamsia	Example: Aurelia

The correct answer is ​Sexual reproduction

Explanation:

• Sponges have a water transport or canal system.
• Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum.
• This pathway of water transport is helpful in food gathering, respiratory exchange and removal of waste.
• Sponges produce gametes (sperm and eggs) directly through their cellular processes, and fertilization can occur inside the sponge or in the water, but this is not a primary function of the water transport system per se.

The correct answer is Hydra.

Key Points

• Hydra is a genus of small, fresh-water organisms of the phylum Cnidaria and class Hydrozoa.
• They are known for their regenerative ability, meaning they can regrow their body parts.
• Hydra is not a member of the phylum Porifera, which consists of sponges.
• Sponges (Porifera) include organisms like Sycon, Spongilla, and Euplectella, which are entirely different from Hydra.

Additional Information

• Phylum Porifera
  • Commonly known as sponges, Porifera are simple, multicellular organisms that live in aquatic environments, mostly marine.
  • They have a porous body structure with channels that allow water to circulate through them, facilitating feeding, respiration, and waste elimination.
  • Sponges have specialized cells called choanocytes that help in water flow and capturing food particles.
  • Examples include Sycon, Spongilla, and Euplectella.
• Hydra
  • Hydra belongs to the phylum Cnidaria, which includes jellyfish, corals, and sea anemones.
  • They are characterized by their simple body structure, radial symmetry, and presence of cnidocytes (stinging cells) used for capturing prey.
  • Hydra are known for their remarkable ability to regenerate, meaning they can regrow any lost or damaged parts of their body.
  • They primarily reproduce asexually by budding, although sexual reproduction can also occur under certain conditions.
• Sycon (Scypha)
  • Sycon is a genus of calcareous sponges belonging to the phylum Porifera.
  • They have a tubular body structure with a single central cavity called the spongocoel.
  • Sycon species are marine and are found attached to rocks or other surfaces underwater.
• Spongilla
  • Spongilla is a genus of freshwater sponges belonging to the family Spongillidae.
  • They are found in lakes, rivers, and streams, often attached to submerged objects.
  • Spongilla sponges have a soft, porous body that filters small food particles from the water.
• Euplectella
  • Euplectella, commonly known as Venus' flower basket, is a genus of glass sponges found in deep ocean environments.
  • They have a unique and intricate skeletal structure made of silica, which provides structural support.
  • Euplectella species are known for their symbiotic relationship with certain shrimp, which live inside the sponge's body for protection.

The correct answer is Collar cells.

 Key Points

• The body of sponges (poriferans) has several minute pores called ostia through which the water enters into the central cavity, spongocoel.
• The flagellated cells called choanocytes (collar cells) line the spongocoel.
• These cells generate a flow of water and the water current helps in food gathering, respiratory exchange and removal of waste.
• The water finally goes out of the body through a large pore called osculum. (Plural: oscula).
• The body wall of the sponge is composed of two layers: outer pinacoderm and inner choanoderm. In between these two layers, mesenchyme is present with various mesenchymal cells.

Additional Information

• Somatic cells make up the connective tissue, skin, blood, bones and internal organs.
• White blood cells are made in the bone marrow. They are stored in your blood and lymph tissues.
• These sex cells are also called reproductive cells or gametes. Sperm cells are produced in men's testicles and egg cells are produced in women's ovaries

Concept:

• According to R.H. Whittaker's five-kingdom system, animals are placed under the Kingdom Animalia.
• Animals are multicellular eukaryotic organisms.
• Animals are heterotrophic and obtain their food from other animals and plants.
•    Kingdom Animalia has 11 different phyla. 

Explanation:

Phylum Porifera:

• Animals belonging to this phylum are called sponges.
• Habitat: These are aquatic animals, most of which are marine and few are freshwater species.
• Lifestyle - Sedentary animals
• Body symmetry: Asymmetrical
• Germ layers: Diploblastic
• Body cavity: Spongocoel
• Body:
  • The body of these animals is considered to be a colony of different types of cells.
  • The body of sponges is supported by either calcareous or siliceous spicules or proteinaceous spongin fibers.
• Ostia and Osculum: 
  • Numerous minute-pores called Ostia are present on the body through which water enters the spongocoel.
  • The osculum is the pore through which water leaves the body.
• Choanocytes: 
  • Spongocoel is lined by special flagellated cells called choanocytes ( collar cells).
  • The beating of the flagella of these cells creates a water current that helps in the pumping of the water in the spongocoel.
  • The collars of the choanocytes are the site of nutrient absorption in the sponges.
• Canal system:
  • Water in the sponges is circulated through the canal system.
  • During the circulation of the water through the canal system, absorption of nutrients, exchange of respiratory gases, and release of excretory products take place.
• Reproduction:
  • Sponges reproduce asexually as well as sexually.
  • Asexual reproduction takes place through fragmentation, gemmule formation, and regeneration.
  • Sexual reproduction takes place by the formation of gametes.
• Fertilization and Development:
  • Fertilization in sponges is internal.
  • Development takes place through the indirect larval stage.
• Example:
  • ​Sycon, Euspongia, etc.

From the above-given information, the correct answer is option 4.

Additional Information

• Sponges are diploblastic animals.
• They have outer ectoderm and inner endoderm with an intermediate layer of mesenchyme cells.

Concept:

• Sponges belong to the phylum Porifera. They are generally marine and mostly asymmetrical animals.
• These are primitive multicellular animals and have a cellular level of organization.

​Explanation:

Euspongia is a marine water sponge, it is also known by the name ''Bath sponge''

Other important characters of Sponges:

• Sponges have a water transport or canal system. Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum.
• This pathway of water transport is helpful in food gathering, respiratory exchange, and removal of waste. Choanocytes or collar cells line the spongocoel and the canals.
• Digestion is intracellular. The body is supported by a skeleton made up of spicules or spongin fibers.
• Sexes are not separate (hermaphrodite), i.e., eggs and sperms are produced by the same individual.
• Sponges reproduce asexually by fragmentation and sexually by the formation of gametes.
• Fertilization is internal and development is indirect having a larval stage that is morphologically distinct from the adult

               Euspongia

Additional Information

The correct answer is Collar cells.

 Key Points

• The body of sponges (poriferans) has several minute pores called ostia through which the water enters into the central cavity, spongocoel.
• The flagellated cells called choanocytes (collar cells) line the spongocoel.
• These cells generate a flow of water and the water current helps in food gathering, respiratory exchange and removal of waste.
• The water finally goes out of the body through a large pore called osculum. (Plural: oscula).
• The body wall of the sponge is composed of two layers: outer pinacoderm and inner choanoderm. In between these two layers, mesenchyme is present with various mesenchymal cells.

Additional Information

• Somatic cells make up the connective tissue, skin, blood, bones and internal organs.
• White blood cells are made in the bone marrow. They are stored in your blood and lymph tissues.
• These sex cells are also called reproductive cells or gametes. Sperm cells are produced in men's testicles and egg cells are produced in women's ovaries

The correct answer is sponges.

Key Points

• Sponges have cellular-level organization, meaning that, 
  • Their cells are specialized so different cells perform different functions.
  • Similar cells are not organized into tissues and bodies are a sort of loose aggregation of different kinds of cells.
• Sponges
  • Sponges, the members of the phylum Porifera, are a basal animal clade as a sister of the diploblastic.
  • They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells.

Additional Information

• Annelids are segmented worms with a tubular body and a specialized digestive system with a terminal mouth and an anus.
• The flatworms or Platyhelminthes are a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates.
• Nematodes are parasites of animals and occur in almost all organs of the body, but the most common sites are in the alimentary, circulatory, and respiratory systems.
• Chordates are animals that bear notochord.
  • It has a dorsal hollow nerve chord.
  • It has pharyngeal gill slits.
  • It has a ventral heart.
  • Phylum Chordata comprises Urochordata, Cephalochordata, and Vertebrata.

Key Points

• Sea cucumber is the common name of a marine animal belonging to the Phylum Echinodermata. 
• The sea cucumber is an exclusively marine species belonging to the Class Holothuroidea.
• It has the following characteristics as a member of the phylum Echinodermata:

1. Pentamerous radial symmetry - the body of an echinoderm can be split along five axes and each segment is radially symmetrical around each of these five axes.
2. It retains pentaradial symmetry too but, since it is elongated and rests on its longitudinal axis, it has secondarily evolved a degree of bilateral symmetry.
3. They have tube feet that assist in locomotion and also serve as canals for a unique water vascular system.
4. The water vascular system plays a crucial role in locomotion, food and waste transportation, and respiration in the sea cucumber and all echinoderms.  
5. The external body surface is cylindrical, leathery, and covered by spines and the animals have a defined endoskeleton.
6. They undergo regeneration of the damaged tissue. 
7. It has a cluster of fine tubes located at the base of the respiratory tree, which is anatomically attached to the cloaca by connective tissue.
8. The respiratory tree is a specialized organ for gas exchange and excretion.
9. This cluster is called the Cuvierian tubules and plays a defensive and protective role in sea cucumbers. 
10. It releases a toxin called Holothurin that immobilizes the prey by paralyzing the body's muscles. 
11. It leads to ocular damage and permanent blindness in humans.

Additional Information

• Sea pen, Sea feather, and Sea fan are all members of Phylum Coelenterata.
• These are evolutionarily primitive as compared to Phylum Echinodermata and collectively encompass two phyla, viz., Cnidaria and Ctenophora.
• These animals are radially symmetrical, have a hollow body cavity, and have tissue level of body organization. 
• Coelenterates exhibit metagenesis, i.e., an alteration between a polyp (asexual) and a medusa (sexual) form.

The correct answer is Hydra.

Key Points

• Hydra is a genus of small, fresh-water organisms of the phylum Cnidaria and class Hydrozoa.
• They are known for their regenerative ability, meaning they can regrow their body parts.
• Hydra is not a member of the phylum Porifera, which consists of sponges.
• Sponges (Porifera) include organisms like Sycon, Spongilla, and Euplectella, which are entirely different from Hydra.

Additional Information

• Phylum Porifera
  • Commonly known as sponges, Porifera are simple, multicellular organisms that live in aquatic environments, mostly marine.
  • They have a porous body structure with channels that allow water to circulate through them, facilitating feeding, respiration, and waste elimination.
  • Sponges have specialized cells called choanocytes that help in water flow and capturing food particles.
  • Examples include Sycon, Spongilla, and Euplectella.
• Hydra
  • Hydra belongs to the phylum Cnidaria, which includes jellyfish, corals, and sea anemones.
  • They are characterized by their simple body structure, radial symmetry, and presence of cnidocytes (stinging cells) used for capturing prey.
  • Hydra are known for their remarkable ability to regenerate, meaning they can regrow any lost or damaged parts of their body.
  • They primarily reproduce asexually by budding, although sexual reproduction can also occur under certain conditions.
• Sycon (Scypha)
  • Sycon is a genus of calcareous sponges belonging to the phylum Porifera.
  • They have a tubular body structure with a single central cavity called the spongocoel.
  • Sycon species are marine and are found attached to rocks or other surfaces underwater.
• Spongilla
  • Spongilla is a genus of freshwater sponges belonging to the family Spongillidae.
  • They are found in lakes, rivers, and streams, often attached to submerged objects.
  • Spongilla sponges have a soft, porous body that filters small food particles from the water.
• Euplectella
  • Euplectella, commonly known as Venus' flower basket, is a genus of glass sponges found in deep ocean environments.
  • They have a unique and intricate skeletal structure made of silica, which provides structural support.
  • Euplectella species are known for their symbiotic relationship with certain shrimp, which live inside the sponge's body for protection.

Concept:

• According to R.H. Whittaker's five-kingdom system, animals are placed under the Kingdom Animalia.
• Animals are multicellular eukaryotic organisms.
• Animals are heterotrophic and obtain their food from other animals and plants.
•    Kingdom Animalia has 11 different phyla. 

Explanation:

Phylum Porifera:

• Animals belonging to this phylum are called sponges.
• Habitat: These are aquatic animals, most of which are marine and few are freshwater species.
• Lifestyle - Sedentary animals
• Body symmetry: Asymmetrical
• Germ layers: Diploblastic
• Body cavity: Spongocoel
• Body:
  • The body of these animals is considered to be a colony of different types of cells.
  • The body of sponges is supported by either calcareous or siliceous spicules or proteinaceous spongin fibers.
• Ostia and Osculum: 
  • Numerous minute-pores called Ostia are present on the body through which water enters the spongocoel.
  • The osculum is the pore through which water leaves the body.
• Choanocytes: 
  • Spongocoel is lined by special flagellated cells called choanocytes ( collar cells).
  • The beating of the flagella of these cells creates a water current that helps in the pumping of the water in the spongocoel.
  • The collars of the choanocytes are the site of nutrient absorption in the sponges.
• Canal system:
  • Water in the sponges is circulated through the canal system.
  • During the circulation of the water through the canal system, absorption of nutrients, exchange of respiratory gases, and release of excretory products take place.
• Reproduction:
  • Sponges reproduce asexually as well as sexually.
  • Asexual reproduction takes place through fragmentation, gemmule formation, and regeneration.
  • Sexual reproduction takes place by the formation of gametes.
• Fertilization and Development:
  • Fertilization in sponges is internal.
  • Development takes place through the indirect larval stage.
• Example:
  • ​Sycon, Euspongia, etc.

From the above-given information, the correct answer is option 4.

Additional Information

• Sponges are diploblastic animals.
• They have outer ectoderm and inner endoderm with an intermediate layer of mesenchyme cells.

Concept:

• Sponges belong to the phylum Porifera. They are generally marine and mostly asymmetrical animals.
• These are primitive multicellular animals and have a cellular level of organization.

​Explanation:

Euspongia is a marine water sponge, it is also known by the name ''Bath sponge''

Other important characters of Sponges:

• Sponges have a water transport or canal system. Water enters through minute pores (ostia) in the body wall into a central cavity, spongocoel, from where it goes out through the osculum.
• This pathway of water transport is helpful in food gathering, respiratory exchange, and removal of waste. Choanocytes or collar cells line the spongocoel and the canals.
• Digestion is intracellular. The body is supported by a skeleton made up of spicules or spongin fibers.
• Sexes are not separate (hermaphrodite), i.e., eggs and sperms are produced by the same individual.
• Sponges reproduce asexually by fragmentation and sexually by the formation of gametes.
• Fertilization is internal and development is indirect having a larval stage that is morphologically distinct from the adult

               Euspongia

Additional Information

The correct answer is Adamsia

Explanation:

• The given diagram indicates Polyp body from
• Adamsia exhibits Polyp body form
• Coelenterates have two basic body forms (Dimorphic)- polyp and medusa.
• Polyp is a sessile and cylindrical form like Hydra, Adamsia, etc. whereas, Medusa is umbrella-shaped and free-swimming like Aurelia or jelly fish.

Polyp	Medusa
Cylindrical in shape like a hydra, adamsia, etc.	Umbrella shaped like Aurelia
Mostly sessile	Free swimming
Asexual form	Sexual form
Example: Adamsia	Example: Aurelia