Question

Identify the animal with a four-chambered heart.
A. Snake
B. Frog
C. Lizard
D. Crocodile

Answer 1

Hint: Reptiles have two auricles and a partly divided ventricle in their body. So, in reptiles, a mixed type of blood circulation is seen.

Complete answer: Crocodile is the only exceptional animal that belongs from class Reptiles and has a four-chambered heart.

Characteristics and features of class reptilia:
1. They are mostly terrestrial animals.
2. The body of these animals is covered by dry and cornified skin, epidermal scales, or scutes.
3. They lack external ear openings, instead, Tympanum represents the ear.
4. Two pairs of limbs are present, when present. (exception: snake)
5. The heart is usually three-chambered, with two atria and one half divided ventricles. But the four-chambered heart is seen in crocodiles.
6. Reptiles are poikilothermic animals. Skin cast is the discarded body scales of snakes and lizards.
7. Sexes are separate and fertilization is internal. They are oviparous animals and development is direct in these animals.
8. Examples include Turtle, Tortoise, Chameleon or Tree lizard, Garden Lizard, Crocodile, Alligator, etc. Hemidactylus reptiles are Wall lizard; some of the reptiles (snakes) are poisonous also, like Naja (Cobra), Krait, Viper.

Additional information: Reptiles are subdivided into several orders and superorder.
Order Chelonia, 300 species of turtles and tortoises having a bony shell on the body includes in this order.
Order Rhynchocephalia (Sphenodontia), 2 species of tuatara (Sphenodon) in New Zealand. These animals consist of acrodont teeth, amphicoelous vertebrae, and a parietal eye.
Order Squamata, with pleurodont teeth, procoelous vertebrae, without third eye.
It has two suborder-
a. Suborder Lacertilia, includes 4000 species of lizards.
b. Suborder Ophidia, includes 2700 species of snakes.
The above-mentioned orders are under some superorder, which is as follows:
Superorder Lepidosauria (lizard-like with acrodont / pleurodont dentition) includes the order Sphenodontia and Squamata.
Superorder Archosauria includes modern crocodiles and extinct dinosaurs.
It includes order Crocodilia, 23 species of alligators, crocodiles, and gharials.

Hence, the correct answer is option D. Crocodile.

Note: Class Reptilia –The class reptilian refers to the animals that creep or crawl in the soil for their locomotion. The word reptilia come from the Latin word repere or reptum meaning to creep or crawl. Snakes, lizards are the most common example of this class.