Q: What is metagenesis? Animals belonging to which phylum exhibit metagenesis?
A: a) Alternation of generations in cnidarians that exist as polyp and medusa is known as metagenesis.
b) Phylum: Cnidaria
Q: Distinguish between amphids and phasmids.
A: a) The chemoreceptors present around oral region of nematodes are known as amphids.
b) The glandulo sensory structures present in the posterior part of many nematodes are known as phasmids.
Q: What is Aristotle's lantern? Give one example of an animal possessing it?
A: a) The five jawed masticatory apparatus present in the mouth of sea urchins (of echinoidea) is called Aristotle's lantern.
Q: Write four salient features of cyclostomes.
A: a) Body of cyclostomes is long, slender, eel like and scale less.
b) Paired fins are absent.
c) Mouth is circular without jaws.
d) Tongue bears horny teeth.
Q: What are claspers? Which group of fishes possess them?
A: a) The copulatory processess developed on Pelvic fins of male cartilagenous fishes are called claspers.
Q: What are the golden ages of first jawed vertebrates and the first amniotes?
A: a) Golden age of first jawed vertebrates (= fishes) was Devonian period of Palaeozoic era.
b) Golden age of first amniotes (= reptiles) was Jurassic period of Mesozoic era.
Q: What are pneumatic bones? How do they help birds?
A: a) The bones with air cavities are known as pneumatic bones.
b) Pneumatic bones make the endoskeleton of birds light (one of the flight adaptations).
Q: How does mature RBC of a Mammal differ from that of other Vertebrates?
A: a) Mature RBC of mammals are circular and biconcave. Where as in other Vertebrates they are oval and convex.
b) Mature RBC of mammals are enucleated. But RBC of other Vertebrates are nucleated.
Q: Name the three meninges. In which group of animals do you find all of them?
A: a) Outer duramater, middle arachnoid mater and inner piamater
Q: What is botryoidal tissue?
A: Characteristic tissue (resembling a bunch of grapes) present in the coelom of hirudineans (Eg: Leech) is called botryoidal tissue. It is believed that this tissue helps in excretion; storage of iron,
Q: What are the respiratory structures in Limulus and Palamnaeus?
A: a) Respiratory organs of Limulus: Book gills
b) Respiratory organs of Plamnaeus: Book lungs