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4.2 Pisces — Test 1
Q1. The scales found in cartilaginous fishes (elasmobranchs) such as sharks are:✓ Placoid scales
Q2. The dried skin of Scoliodon (dogfish), used as an abrasive for polishing, is called:✓ Shagreen
Q3. The largest living fish in the world is the:✓ Whale shark (Rhincodon typus)
Q4. Sharks and rays belong to the group:✓ Elasmobranchii (cartilaginous fishes)
Q5. Lungfishes (which can breathe air) belong to the group:✓ Dipnoi
Q6. A fish that migrates from the sea to fresh water to spawn is called:✓ Anadromous
Q7. A fish that migrates from fresh water to the sea to spawn (e.g. the eel Anguilla) is called:✓ Catadromous
Q8. Weberian ossicles, which transmit sound from the swim bladder to the inner ear, are found in:✓ Certain bony fishes
Q9. The swim bladder (air bladder) of a teleost fish primarily helps in:✓ Maintaining buoyancy
Q10. In the seahorse (Hippocampus), the eggs are incubated in a brood pouch of the:✓ Male
Q11. Gambusia affinis is well known for its:✓ Larvivorous nature (eating mosquito larvae)
Q12. The teeth of sharks are essentially modified:✓ Placoid scales
Q13. Torpedo, the electric ray, can produce electricity using:✓ Modified muscle (electric organs)
Q14. Cartilaginous fishes differ from bony fishes in that cartilaginous fishes:✓ Lack a bony skeleton and an operculum
Q15. The accessory respiratory organs of the climbing perch (Anabas) allow it to:✓ Breathe atmospheric air out of water
Q16. Bony fishes (Osteichthyes) are characterised by having:✓ A bony skeleton and an operculum covering the gills
4.2 Pisces — Test 2
Q17. The lateral line system of fishes detects:✓ Water movements and vibrations
Q18. Mouth-brooding, where the parent incubates eggs in the mouth, is shown by:✓ Oreochromis (Tilapia)
Q19. The respiratory organs of fishes are the:✓ Gills
Q20. The heart of a fish is two-chambered and pumps:✓ Only deoxygenated blood (single circulation)
Q21. Hilsa (Tenualosa ilisha) is an example of a fish that is:✓ Anadromous (migrates from sea to rivers to breed)
Q22. Lamprey, a jawless fish, belongs to the group:✓ Cyclostomata (Agnatha)
Q23. The gills of bony fishes are protected and covered by the:✓ Operculum
Q24. Counter-current flow in fish gills is efficient because water and blood flow:✓ In opposite directions, maximising oxygen uptake
Q25. The pelvic fins of a fish function mainly in:✓ Balance and steering
Q26. Cycloid and ctenoid scales are characteristic of:✓ Bony fishes (teleosts)
Q27. The air bladder of a teleost with an open duct to the gut is called:✓ Physostomous
Q28. Fishes are cold-blooded, meaning their body temperature:✓ Varies with the surrounding water
Q29. Sharks maintain buoyancy without a swim bladder mainly by using:✓ A large oil-rich liver
Q30. The class Pisces is most diverse among vertebrates, the largest sub-group being the:✓ Teleosts (advanced bony fishes)
Q31. The main excretory product of most freshwater bony fishes is:✓ Ammonia
Q32. Freshwater fishes must constantly excrete water and absorb salts because their body fluids are:✓ Hypertonic to the surrounding water