Question

Which one of the following is characteristics of birds?
A. They are aquatic animals.
B. They are cold blooded.
C. They are bipedal and have feathers.
D. They are quadruped and have scales.

Answer 1

Hint:- Class Aves are a category of warm-blooded vertebrates with a heavy but light skeleton, characterised by toothless beaked jaws, hard-shelled egg laying, a high metabolic rate, a four-chambered heart.

Complete step-by-step solution:-
Option A is incorrect. A mammalian vertebrate or invertebrate that lives in the water for most or all of its lifespan is an aquatic species. Several species with winged adults, such as mosquitoes, mayflies, dragonflies and caddisflies, have aquatic larvae. In addition to water-breathing species, e.g. fish, most molluscs, etc., the word 'aquatic animal' can refer to aquatic or sea-breathing air-breathing mammals, such as Cetacea (whales) and Sirenia (sea cows), which cannot live on land, as well as to pinnipeds (true seals, eared seals, and walrus).
Option B is incorrect. There is a body temperature for a cold-blooded animal that varies along with the outside temperature. Animals who are unable to regulate their body temperature, such as reptiles, fish, and amphibians, and are thus slow in cold weather. (Compare animals with warm blood.)
Option C is correct. Mammals such as birds are also warm-blooded and, like birds, certain mammals such as bats also fly in the air. All birds are bipedal and, with the exception of hind limbs and forelimbs, the body is coated with feathers modified into wings. There is no quadruple eagle, and birds do have scales on the hind limbs.
Option D is incorrect. The number of quadrupeds, including mammals such as horses, dogs and cats, and reptiles such as lizards, are vertebrate species. A few other species are quadrupedal, although a few birds, such as the shoebill, often use their wings to correct themselves after lunging at prey. Reptiles and pangolins are the only species completely covered in scales, and they use those scales to protect themselves from predators in the wild.
So, the correct answer is Option C.

Note:- As food for human consumption and raw materials for processing, many species of birds are economically important, with domesticated and undomesticated birds being important sources of eggs, meat, and feathers. Insectivores, frugivores, and nectarivores may be birds. Generally, aquatic birds feed by fishing, plant eating, and piracy or kleptoparasitism.