40 Questions
Hydra is a marine animal
False
Hydra feeds on small crustaceans and insect larvae
True
Hydra reproduces only asexually
False
The body of Hydra is elongated and has a basal disc for attachment
True
Hydra has a respiratory and circulatory system
False
Hydra belongs to the phylum Platyhelminthes
False
The main unit of excretory system in Hydra is flame cell
False
Most Platyhelminthes are parasitic animals
True
Platyhelminthes have a simple digestive system with no anus
True
Platyhelminthes are exclusively hermaphroditic except for Schistosoma
True
Phylum Cnidaria (coelenterata) includes about 9000 species.
True
Cnidarians are the simplest of eumetazoans.
True
The body of cnidarians consists of three layers.
False
Cnidarians reproduce only sexually.
False
Cnidarians have bilateral symmetry.
False
Hydrozoa is a class of Cnidarians found only in marine habitats.
False
Medusoid form is one of the stages in the life cycle of Cnidarians.
True
Cnidarians have a calcareous skeleton.
True
Cnidarians have a cavity in the body called coelenteron.
True
Sea anemones belong to the class Anthozoa.
True
What is the habitat of Hydra?
Freshwater
Where are the testes found in Hydra?
In the anterior third of the body
How does Hydra reproduce during normal conditions?
By budding
What is the main unit of the excretory system in Hydra?
Flame cell
How does Hydra obtain its food?
By filter feeding
What type of symmetry do Platyhelminthes exhibit?
Bilateral symmetry
What is the main unit of the excretory system in most Platyhelminthes?
Flame cell
How do most Platyhelminthes obtain nutrients?
Through parasitism
Which class does Hydra belong to within the phylum Cnidaria?
Hydrozoa
What is the structure at the distal end of Hydra that has a mouth on hypostome?
Tentacles
What is the main characteristic of the body of cnidarians?
Presence of nematoblasts for defense
How do cnidarians reproduce?
Sexually by forming gametes
What type of symmetry do most cnidarians exhibit?
Radial symmetry
Where are the testes found in Hydra?
In the gastrovascular cavity
What is the habitat of most cnidarians?
Marine
What is the main unit of the excretory system in most cnidarians?
Flame cell
Which class of cnidarians includes Hydra and Obelia?
Hydrozoa
What are nematoblasts used for in cnidarians?
Predation and defense
What is the function of coelenteron in the body of cnidarians?
Digestion, excretion, and gas exchange
What is the main form of reproduction seen in cnidarians?
Both asexual by budding and sexual by forming gametes
Study Notes
Characteristics of Hydra
- Hydra is a marine animal that feeds on small crustaceans and insect larvae.
- It has an elongated body with a basal disc for attachment.
- Hydra has a respiratory and circulatory system.
Reproduction and Excretory System
- Hydra reproduces asexually.
- The main unit of the excretory system in Hydra is the flame cell.
Classification and Characteristics of Platyhelminthes
- Hydra belongs to the phylum Platyhelminthes.
- Most Platyhelminthes are parasitic animals.
- They have a simple digestive system with no anus.
- Platyhelminthes are exclusively hermaphroditic except for Schistosoma.
Characteristics of Cnidarians
- Phylum Cnidaria (coelenterata) includes about 9000 species.
- Cnidarians are the simplest of eumetazoans with a body consisting of three layers.
- They reproduce sexually and have bilateral symmetry.
- Hydrozoa is a class of Cnidarians found only in marine habitats.
- The medusoid form is one of the stages in the life cycle of Cnidarians.
- Cnidarians have a calcareous skeleton and a cavity in the body called coelenteron.
- Sea anemones belong to the class Anthozoa.
Learn about the characteristics and classification of the Phylum Cnidaria (Coelenterata), which includes approximately 9000 species of animals found in both freshwater and marine environments. Explore the unique features of this group of animals and their significance in the animal kingdom.
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