Hemichordata and Minor Phyla Practice Questions
20 free Hemichordata and Minor Phyla practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Hemichordates are primarily classified under which level of organization?
- A Cellular level
- B Tissue level of organization
- C Organ level
- D Organ-system level
Correct answer: Organ-system level
Hemichordates exhibit organ-system level organization. Their body is divided into proboscis, collar, and trunk.
Which of the following is a characteristic feature of Hemichordata?
- A True notochord
- B Presence of jointed appendages
- C Radial symmetry
- D Presence of stomochord
Correct answer: Presence of stomochord
Hemichordates possess a stomochord, a structure once thought to be similar to a notochord but functionally different.
Hemichordates are generally found in which habitat?
- A Freshwater
- B Terrestrial
- C Aerial
- D Marine
Correct answer: Marine
Hemichordates are exclusively marine organisms. They usually live in burrows in sandy or muddy substrates.
Which of the following is an example of Hemichordata?
- A Balanoglossus
- B Ascidia
- C Salpa
- D Herdmania (Sea squirt)
Correct answer: Balanoglossus
Balanoglossus is a classic example of Hemichordata. It is also known as an acorn worm.
The body of hemichordates is divided into how many main regions?
- A Three
- B Two
- C Four regions
- D Five
Correct answer: Three
The body of hemichordates is divided into proboscis, collar, and trunk. This tripartite division is characteristic of the group.
Hemichordates show which type of symmetry?
- A Radial symmetry
- B Bilateral symmetry
- C Asymmetry
- D Spherical symmetry
Correct answer: Bilateral symmetry
Hemichordates exhibit bilateral symmetry. This means their body can be divided into two equal halves along one plane.
Which type of circulatory system is present in hemichordates?
- A Closed circulatory system
- B Open circulatory system
- C No circulatory system
- D Double circulatory system
Correct answer: Open circulatory system
Hemichordates possess an open circulatory system. Blood is not confined entirely to vessels.
Which of the following is a minor phylum among chordate relatives?
- A Porifera
- B Hemichordata
- C Cnidaria
- D Platyhelminthes
Correct answer: Hemichordata
Hemichordata is considered a minor phylum and shares some features with chordates.
Which structure in hemichordates was previously considered homologous to the notochord?
- A Proboscis
- B Collar
- C Stomochord
- D Gill slits
Correct answer: Stomochord
The stomochord was initially thought to be similar to the notochord. However, it differs structurally and functionally.
Which respiratory structure is present in hemichordates?
- A Trachea
- B Book lungs
- C Gill slits
- D Skin only
Correct answer: Gill slits
Hemichordates respire through gill slits present in the pharynx. This is a chordate-like feature.
The marine animal Herdmania is classified under which of the following groups?
- A Hemichordata
- B Urochordata
- C Cephalochordata
- D Vertebrata
Correct answer: Urochordata
Herdmania, the sea squirt, is a urochordate: its notochord is confined to the tail of the larva and is lost in the adult. Cephalochordates such as Branchiostoma retain the notochord along the whole body for life, vertebrates replace it with a vertebral column, and Hemichordata is now placed outside Chordata altogether.
Which minor phylum includes organisms like Amphioxus?
- A Hemichordata
- B Urochordata
- C Cephalochordata
- D Echinodermata
Correct answer: Cephalochordata
Amphioxus belongs to Cephalochordata. It retains notochord throughout life and shows primitive chordate features.
Which of the following is a feature shared by hemichordates and chordates?
- A Jointed appendages
- B Gill slits
- C Segmented body
- D Notochord
Correct answer: Gill slits
Both hemichordates and chordates possess pharyngeal gill slits. This suggests evolutionary relationships.
Which type of fertilization is generally seen in hemichordates?
- A Internal fertilization
- B External fertilization
- C Asexual reproduction only
- D Budding
Correct answer: External fertilization
Hemichordates usually exhibit external fertilization. Gametes are released into water.
Which minor phylum shows retrogressive metamorphosis?
- A Hemichordata
- B Cephalochordata
- C Echinodermata
- D Urochordata
Correct answer: Urochordata
Urochordates like Herdmania show retrogressive metamorphosis. The larva has more advanced features than the adult.
Which of the following best describes the stomochord?
- A Digestive organ
- B Respiratory organ
- C Excretory organ
- D Support structure
Correct answer: Support structure
The stomochord is a supportive structure located in the proboscis. It is not a true notochord.
Hemichordates belong to which type of coelom?
- A Acoelomate
- B Pseudocoelomate
- C True coelomate
- D Hemocoel
Correct answer: True coelomate
Hemichordates are true coelomates. They possess a well-developed body cavity lined by mesoderm.
Which minor phylum retains notochord throughout life?
- A Urochordata
- B Hemichordata
- C Cephalochordata
- D Platyhelminthes
Correct answer: Cephalochordata
Cephalochordates like Amphioxus retain the notochord throughout life. This is a key chordate feature.
Which of the following features is absent in hemichordates?
- A Notochord
- B Gill slits
- C Bilateral symmetry
- D Coelom
Correct answer: Notochord
Hemichordates lack a true notochord. Instead, they possess a stomochord.
Which structure is used for feeding and burrowing in hemichordates?
- A Proboscis
- B Collar
- C Trunk
- D Gill slits
Correct answer: Proboscis
The proboscis is used for burrowing and feeding in hemichordates. It plays a key role in their lifestyle.