Hemichordata is a phylum of marine animal and it is considered as the sister of Echinodermata. They have an organ-system level of organization. The notochord is absent many taxonomists do not consider this animal as chordates body of hemichordate is divisible into proboscis, collar, and trunk. They have a digestive system with open mouth and ciliary feeders. They feed on planktons, sand, and mud to digest organic matter from it there is a preoral extension of the gut called stomochord in proboscis region. They respire through U shaped dorso-ventral pharyngeal gill slits. Single glomerulus in probosci's act as an excretory organ. Sensory cells in the epidermis. Their larva is Tornaria because of its habit of rotating in a circle. Tornaria resembles bipinnaria of echinoderms and is a connecting link between echinoderms and chordates. So take this quiz and test your knowledge about phylum Hemichordate.
1. Gastrula formation in hemichordates involve....
A. Invagination
B. Ingression
C. Epiboly
D. None of these
2. The non-contractile heart is a characteristic of.....
A. Asterias
B. Balanoglossus
C. Pila
D. Pheretima
3. Balanoglossus lives in....
A. U shaped burrow
B. Vertical burrow
C. Open Sea
D. Horizontal burrow
4. Notochord like structure in buccal reason in hemichordates is....
A. Protochord
B. Pallium
C. Stomochord
D. Mantle
5. Which coelom in Balanoglossus does not open out?
A. Protocol
B. Metacoel
C. Mesocoel
D. All of the above
6. Fertilization in balanoglossus occurs in....
A. Genital Wings
B. Sea water
C. Sometimes external and sometimes internal
D. None of the above
7. The notochord is higher vertebrates from....
A. Brain and spinal cord
B. Gill slit
C. Muscles
D. Vertebral column
8. In hemichordates, the dorsal nerve cord is...
A. Absent
B. Present throughout length
C. Restricted to collar reason
D. Restricted to tail reason
9. Hemichordates have....
A. Closed circulation, colourless blood
B. Closed circulation, coloured blood
C. Open circulation, coloured blood
D. Open circulation, colourless blood
10. Which one of the following is not an example of hemichordates?
A. Acorn worm
B. Pterobranchia
C. Balanoglossus
D. Mussels
11. Which one of the following is the similarity between Hemichordata and Chordata?
A. Both are triploblastic
B. Both have notochord
C. Both have epidermal nervous system
D. None of these
12. Acorn worms have proboscis for ....
A. Feeding
B. Burrowing
C. Both of these
D. None of these
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