Assertion: At the first glance, the top surface of the Morpho butterfly's wing appears a beautiful blue-green. If the wind moves the colour changes.
Reason: Different pigments in the wing reflect light at different angles.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are truw but reason is not correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false.

Answer

C

Explanation

Many Morpho butterflies are coloured in metallic,shimmering shades of blue and green.These colours are not due to pigmentation but due to iridescence: the extremely fine lamellated scales covering the Morpho's wings reflect incident light repeatedly at successive layers leading to interference effect that depends on both the wavelengths and angle of incidence.Thus the colours produced vary with viewing angle.However they are actually surprisingly uniform,perhaps due to the tetarahedral(diamond-like)structural arrangement of scales or diffraction from overlying cell layers.This structure may be called photonic crystal.