Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Gait of Animals refers to the specific pattern or manner of movement of limbs during locomotion.
Earthworms move by alternate extension and contraction of the body using muscles. They use tiny hair-like bristles called setae () to grip the ground.
Snails move using a large, disc-shaped muscular foot. They secrete a slimy substance called mucus, which reduces friction () and allows them to glide over surfaces.
Cockroaches possess a hard outer skeleton called an exoskeleton. They move using three pairs of legs for walking and two pairs of wings for flying.
Birds have adapted for flight with hollow (pneumatic) bones to reduce weight and strong flight muscles attached to the breastbone. Their forelimbs are modified into wings.
Fish have a streamlined body shape that reduces water resistance or drag (). They move by forming curves on alternate sides of the body, creating a push against the water.
Snakes have a long backbone and many thin muscles. They move in a loop-like manner; each loop of the snake gives it a forward push by pressing against the ground. Snakes do not move in a straight line.
📐Formulae
(Pressure exerted by an animal's foot on the ground depends on Force and Area )
(Force of friction depends on the coefficient of friction and normal force )
💡Examples
Problem 1:
Why is the body of a fish described as 'streamlined'?
Solution:
The head and tail of the fish are smaller than the middle portion of the body.
Explanation:
This shape allows water to flow around it easily, minimizing the resistance or drag () and allowing the fish to move quickly through the water.
Problem 2:
How does an earthworm use its muscles to move forward?
Solution:
The earthworm first extends the front part of the body while keeping the rear portion fixed to the ground. Then it fixes the front end and releases the rear end.
Explanation:
This sequence of muscular expansion and contraction, combined with the grip of setae (), results in a net forward displacement.
Problem 3:
Explain why snakes move in a wavy pattern rather than a straight line.
Solution:
A snake's body curves into many loops. Each loop of the snake gives it a forward push by pressing against the ground.
Explanation:
Since the push is directed sideways and forward from multiple loops, the resulting motion is a fast, slithering wave. Because it relies on these lateral pushes, it cannot move in a perfectly straight line efficiently.