Which term describes a method of locomotion in snakes that involves bending and straightening the body?

Which term describes a method of locomotion in snakes that involves bending and straightening the body?

• A. Undulation
• B. Fang
• C. Concertina
• D. Venom

Answer: (C)

Understanding snake movement means looking at how the body bends and pushes against the surroundings. In concertina locomotion, the snake creates a series of tight bends or folds, braces part of its body against a surface, and then straightens another section to pull forward. This alternation between bending to anchor and straightening to extend is the defining pattern of this mode, and it’s especially useful in narrow spaces or gaps where a smooth sliding wave won’t work.

Other options aren’t about this kind of anchored, bend-and-pull motion. Lateral undulation uses continuous waves running along the sides of the body, not a clear anchor-and-reposition sequence. Features like fangs or venom are about defense or prey capture, not movement mechanics. So the term that best fits the description is concertina.