Question

Which of the following has a beak with jaws but no teeth?
A. Aves
B. Snakes
C. Mammals
D. All the above

Answer 1

Hint:
Birds are a group of warm-blooded vertebrates, characterized by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.
Birds have wings whose development varies according to species.

Complete step by step answer:
The birds belong to the class of caves.
The characteristics of aves are the presence of feathers and most of them can fly except flightless birds such as ostrich.
They possess beak.
The forelimbs of the beak are modified into wings.
The hind limbs generally have scales and are modified for walking, swimming or clasping of bird branches.
Skin is dry without glands except the oil glands.
Endoskeleton is fully bony and the long bones are hollow with air cavities.
The digestive tract of birds has additional chambers, the crop and gizzard.
Heart is completely four chambered and are warm blooded animals that means they are able to maintain a constant body temperature.
Lungs are very helpful for respiration.
Air sacs are connected to lungs and sexes are separate and fertilisation is internal.
Aves class includes Crow, Pigeon, Peacock etc.
Snakes have curved teeth to prevent the escape of prey and flexible jaws help them to catch the larger prey.
Mammals also consist of teeth.
So, the correct option is option “A” Aves.

Note:
Birds live and breed in most terrestrial habitats and on all seven continents, reaching their southern extreme in the snow petrel's breeding colonies up to 440 kilometres (270 mi) inland in Antarctica.
The highest bird diversity occurs in tropical regions. It was earlier thought that this high diversity was the result of higher speciation rates in the tropics; however recent studies found higher speciation rates in the high latitudes that were offset by greater extinction rates than in the tropics.