When the light passes through the solution, then scattering of light by colloidal particles is observed and path of light beam becomes visible. This phenomenon is known as Tyndall effect

Starch solution is a colloidal solution; hence, it will show Tyndall effect.

When X is added water then the solution becomes suspension which is a heterogeneous mixture.

In second case, the particles settle down which were suspended throughout the bulk and the path became not visible.

Milk is a colloid with small particles of butterfat suspended through the liquid.