Question

28. Which of the following statements are not true about amphibians? 1. Alimentary canal, urinary and reproductive tracts open into a common chamber called cloaca II. Ten pairs of cranial nerves are present III. RBCs are biconvex, oval and enucleated IV. Skull is monocondylic 2) II, III and IV 3) III and IV 4) 1, II and IV 1) I and III​

Answer 1

Answer:

4) 1, II and IV is the true statement

Answer 2

Amphibians are tetrapod animals that are ectothermic and belong to the class Amphibia. Lissamphibia is the name given to all live amphibians. They live in a broad range of environments, with the majority of species inhabiting terrestrial, fossorial, arboreal, or freshwater aquatic settings. As a result, most amphibians begin their lives as larvae in water, although certain species have evolved behavioural adaptations to avoid this.

The larvae with gills metamorphose into an adult air-breathing species with lungs in most cases. Amphibians utilise their skin as a secondary respiratory surface, and some tiny terrestrial salamanders and frogs do not have lungs and rely only on their skin for respiration. They resemble lizards on the surface, but reptiles, like mammals and birds, are amniotes, which means they don't need water to reproduce. Amphibians are typically ecological indicators due to their complicated reproductive demands and porous skins; amphibian populations have been declining dramatically for several species throughout the world in recent decades.

The first amphibians developed from sarcopterygian fish with lungs and bony-limbed fins, which helped them adapt to dry land during the Devonian period. During the Carboniferous and Permian eras, they evolved and were dominant, but were eventually replaced by reptiles and other animals. Amphibians have shrunk in size and variety through time, leaving just the Lissamphibia subclass.

Anura (frogs), Urodela (salamanders), and Apoda (amphibians) are the three extant amphibian orders (the caecilians). There are roughly 8,000 amphibian species known, with frogs accounting for nearly 90% of them. A frog from New Guinea (Paedophryne amauensis) is the world's tiniest amphibian (and vertebrate), measuring just 7.7 mm in length (0.30 in). The 1.8 m (5 ft 11 in) South China giant salamander (Andrias sligoi) is the biggest extant amphibian, although it is dwarfed by the extinct 9 m (30 ft) Prionosuchus from the middle Permian of Brazil. Batrachology is the study of amphibians, whereas herpetology is the study of both reptiles and amphibians.