Question

Large size scales fully extended from side to side on belly are unique to
A. Non-venomous snakes
B. Venomous snakes
C. Viviparous snakes
D. Oviparous snakes

Answer 1

Hint: Different type of scales arrangement represents something unique about that particular category of snakes. Scales help to identify specific categories of snakes. Scales on their body perform various important functions like locomotion, protection, and it also helps in retaining moisture from the environment. These types of adaptation help them in camouflage to hide them from their prey.

Complete step by step answer: Scales on the body of the snakes primarily works for reducing friction of their body so that less energy is lost from their bodies. Belly or ventral scales are large and oblong, especially have low friction. Arboreal species use their edges to make grip on the branches on trees. Scales on their body receive vibrations from the surroundings. They can easily differentiate between two by using a complex system of internal resonances. Evolution of reptiles occurs from amphibians which left their aquatic lifestyle and become terrestrial.
Arrangement of scales is also important for forensic reasons and also for the conservation of snake species. Head of the snakes does not have imbricate scales (like the tiles of roof) ; many specialized scales are also observed on the head and other regions of the body. Scales are arranged in rows on the dorsal body. Odd number of scales is present on it. Example - Zaocys spp.
In aquatic or marine snakes rows and granular arrangement of scales cannot be counted. Mid-body of the snakes has more scales and lesser scales arrangement on head and tail.
If there is no difference found on dorsal and ventral scales of the snakes. The snake is identified as non-poisonous.
If broad type arrangement occurs in ventral scales not covering the belly part then it is identified as a non-poisonous land snake but if scales run completely across the belly in broad pattern then the snake is identified as to be a poisonous snake.
As we have discussed above venomous snakes have large size scales fully extended from side to side on their belly that is a unique pattern to identify them.
So the correct answer is option B.

Note: Venomous snakes and non-venomous snakes can be easily differentiated by identifying the scales arrangement on their body. There are mainly three types of scales that are head scales, body scales and tail scales. Water snakes, pipe snakes, boas are some viviparous snakes. Colubridae is the largest family of snakes that have about 15, 17 or 19 rows of scales.