Question

A poisonous lizard is ___________________.
A. Heloderma
B. Agkistrodon
C. Chamaeleon
D. Varanus

Answer 1

Hint:- Lizards are a widespread group of reptiles with squamates. Many lizards, moving with a powerful side-to - side motion, are quadrupedal. Others are legless and have snake-like bodies that are long.

Complete step-by-step solution:- Big, stocky, slow-moving reptiles that prefer semi-arid climates are Heloderma, or beaded lizards. Their tails are brief and used as organs for fat preservation. Small, non-overlapping, bead-like scales cover them, with osteoderms on the undersides of their limbs. Both animals with yellowish or pinkish markings are black in colour. Lizards with beads are venomous. Unlike snakes' poison glands, which are found in their upper jaws, poison glands are located in their lower jaws.

Agkistrodon is a genus of venomous pit vipers and the common name 'moccasin' or 'moccasin snake' is given to several varieties of the genus. The earliest recorded use of "moccasin" to refer to a venomous mortal serpent.For their life, pit vipers of the genus Agkistrodon rely on a strong venom that they produce. One strike, used to immobilise animals and ward off predators, can inject enough venom into a human being to cause extreme discomfort, swelling, fatigue, respiratory problems, haemorrhaging, gangrene, fever , vomiting, and even death in exceptional situations.

Species in the genus Chamaeleo are slow-moving, with eyes moving independently, the ability to change the colour of the face, a long tongue, generally a prehensile tail, and unique adaptations of the legs for vegetation gripping.

In the genus Varanus, monitor lizards are big lizards. The majority of monitor lizards are almost exclusively carnivorous, eating prey as diverse as rodents, crustaceans, arachnids, myriapods, molluscs, fish , amphibians, birds, reptiles , and mammals. As juveniles, most animals feed on invertebrates and move as adults to feeding on vertebrates.

So from these discussions we can conclude that Heloderma is the poisonous lizard in the given options. Therefore the correct answer is option (A).

Note:- Lizards are primarily carnivorous and are mostly sit-and-wait predators; insects are eaten by much smaller animals. The males fend off other males and signal, often in vivid colours, to attract mates and threaten rivals. They are often territorial. A host of anti-predator adaptations are used by lizards, including venom, camouflage, reflex bleeding, and the ability to sacrifice and regrow their tails.