Question

Assertion : When a beetle moves along the sand within a few tens of centimeters of a sand scorpion, the scorpion immediately turns towards the beetle and dashes towards it.

Reason : When a beetle disturbs the sand, it sends pulses along the sand'* surface. One set of pulses is longitudinal while the other set is transverse.

(a) Both A and R are true and R is the correct explanation of A

(b) Both A and R are true but R is not correct explanation of A

(c) A is true but R is false

(d) A and R are false

Answer 1

The correct option is (a) Both A and R are true and R is the correct explanation of A.

Explanation:

A beetle' motion sends fast longitudinal and slower transverse waves along the sand' surface. The sand scorpion intercepts the longitudinal waves first and learns the direction of the beetle by noting which one of the eight legs of the scorpion is ***** first by the pulses. Then the scorpion dashes towards the beetle to catch it.