Chordata origin and classification, phylogeny of Hemichordata, Urochordata, Cephalochordata, retrogressive metamorphosis - Question Bank
1. In the context of chordate phylogeny, the significance of Cephalochordates lies in their:
2. The loss of a functional tail in the adult tunicate is an example of evolutionary simplification, characteristic of:
3. Which of the following statements accurately reflects the proposed phylogeny of chordates?
4. The classification of Chordata into subphyla Urochordata, Cephalochordata, and Vertebrata is based on the presence, persistence, and location of key chordate characteristics.
5. The 'tail' in the larval tunicate is absorbed during metamorphosis. This is a key event in:
6. Which of the following is an example of a sessile Urochordate?
7. The phylogenetic link between Hemichordata and Chordata is strengthened by the presence of:
8. The coelom of Hemichordates is divided into three parts: protocoel (in the proboscis), mesocoel (in the collar), and metacoel (in the trunk).
9. Which subphylum of chordates displays a persistent notochord throughout its life, functioning as a primary skeletal support?
10. The process by which the larval tunicate develops into a sessile, simplified adult is termed:
11. The term 'chordate origin' primarily refers to the evolutionary development and derivation of which key features?
12. The 'gill bars' in Cephalochordates are supported by:
13. Which genus represents a colonial tunicate exhibiting the phenomenon of retrogressive metamorphosis?
14. The phylogenetic relationship between Hemichordata and Echinodermata is suggested by:
15. The Tunicata (Urochordata) are characterized by their sessile adult form and free-swimming larval form. This lifestyle adaptation is thought to be linked to:
16. Which of the following is a key difference between Hemichordates and true Chordates?
17. The evolutionary origin of the chordate pharyngeal slits is hypothesized to be related to:
18. Amphioxus exhibits a distinct segmentation in its musculature, known as:
19. Which feature, found in the larval stage of Urochordates, is lost in the adult stage, leading to retrogressive metamorphosis?
20. The 'collar' in Hemichordata is homologous to which chordate structure?
21. Retrogressive metamorphosis is particularly evident in which group of chordates?
22. In Cephalochordates, the notochord provides skeletal support and extends:
23. The subphylum Urochordata includes organisms like:
24. Which statement best describes the 'phylogeny of chordates' in relation to the protochordates?
25. The phylogenetic placement of Hemichordata has historically been controversial, with some earlier classifications placing them closer to:
26. Which of the following is NOT a characteristic of Balanoglossus (a Hemichordate)?
27. The loss of the notochord and tail in the adult tunicate, while retaining other chordate features like the pharynx, is a prime example of:
28. What is the primary function of the endostyle in Cephalochordates?
29. The 'Amphioxus' lancelet is a representative of which chordate subphylum?
30. The phylogenetic significance of Hemichordata lies in its possession of some chordate-like features, particularly in the pharyngeal region, and a unique proboscis structure.
31. Which of the following is a distinguishing feature of Cephalochordates compared to Urochordates?
32. The 'tunic' in tunicates is made up of a cellulose-like substance called:
33. In the evolutionary lineage leading to vertebrates, which group is considered the sister group to Vertebrata, sharing the most recent common ancestor?
34. The dorsal hollow nerve cord in chordates develops from the:
35. Which of these organisms is a well-known example of a Hemichordate?
36. The term 'retrogressive metamorphosis' in tunicates implies:
37. The classification of Hemichordata as a separate phylum is supported by the presence of a proboscis associated with a coelom, termed:
38. Which of the following is a characteristic feature of the Urochordate larva?
39. The endostyle, present in Urochordata and Cephalochordata, is homologous to which part of the vertebrate thyroid gland?
40. Cephalochordates are considered important in understanding chordate evolution because they:
41. Tunicates, belonging to Urochordata, are also known as sea squirts. Their larval stage is free-swimming and exhibits all chordate hallmarks. What is the name of the structure that absorbs the tail in the adult tunicate?
42. In Hemichordates like Balanoglossus, the 'collar' region contains a structure that was once mistakenly identified as a notochord. What is this structure called?
43. The phylogenetic origin of chordates is a subject of ongoing debate. The 'Protochordate' theory suggests a relationship with which group?
44. Which of the following is NOT a characteristic feature of chordates?
45. The pharyngeal gill slits in chordates are primarily involved in:
46. Which genus is a classic example of Cephalochordata, known for its fish-like appearance and persistent notochord extending into the head region?
47. In Urochordata, the larval stage possesses all the typical chordate characteristics. What is the phenomenon called when the adult stage loses some of these characteristics?
48. Which structure in Hemichordata, though superficially resembling the chordate notochord, is actually an evagination of the pharyngeal wall and thus not homologous?
49. The notochord, a key characteristic of chordates, is derived from which embryonic germ layer?
50. Which of the following is considered the most primitive chordate group, exhibiting characteristics that bridge the gap between invertebrates and vertebrates?