Tyndall effect is observed when sunlight passes through canopy of a dense forest because:A) In the forest, mist contains tiny droplets of water which act as particles of colloid dispersed in air.B) In the forest smog, fog is present which contains droplets of water which act as particles of colloid dispersed in air.C) In the forest, tree leaves contain chloroplast which contains guard cells, which act as particles of colloid dispersed in air.D) All of the above.

The Tyndall effect is the scattering of light as it passes through a colloidal dispersion, such as a mist, fog, or any other particles dispersed in a medium. In a dense forest, when sunlight passes through the canopy, it encounters various particles like water droplets from mist or fog, as well as other suspended particles in the air such as pollen, dust, and tiny debris from leaves. These particles scatter the sunlight, making the light visible in different directions and causing the characteristic glow observed in the forest. Therefore, the correct answer is:

A) In the forest, mist contains tiny droplets of water which act as particles of colloid dispersed in air.
B) In the forest smog, fog is present which contains droplets of water which act as particles of colloid dispersed in air.

So, the correct choice is D) All of the above.