Read the assertion and reson carefully to mark the correct option out of the options given below:
Assertion : Sparrow possess poor night vision
Reason : Sparrows eyes are made up of ommatidia .

Options

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

Answer

C

Explanation

The light sensitive inner layer of eyeball called retina contain photoreceptors viz, rod and cone cells which convert the energy of specific wavelengths of light into action potentials of nerve fibres. Cone cells are sensitive to bright light only. So, they help to see in dayliggt or in a brightly illuminated room by electric lamps. Rod cells are sensitive even to dim light and at night. Animals like sparrows, which are active only in day time, have mostly cone cells in their retina and therefore they possess poor night vision. Ommatidia are the elongated tube like units of a compound eye present in higher invertebrates like prawns, crabs and insects Ommatidia are crowded over a spherical surface. Each focusses the light from a small area of the object so that is mosaic of a large number of images of the adjacent areas of the object are formed by numerous ommatidia. A fusion of these images may produce a composite blurred image of the object.