Questions

Phosphorescence is a phenomenon associated with an algal division called euglenophytes. 

Phosphorescence is a phenomenon when an object is capable of releasing photons of light at a longer wavelength in response to absorbing light of a shorter wavelength. The object releasing the light only releases the light after some time has passed since it absorbed the light of a short wavelength.

Euglenophytes are single-celled plant-like protists that have no cell wall.

Genes are units of heredity.

Cast iron is a group of iron-carbon alloys with a carbon content greater than 2% and is a brittle material.

Its usefulness derives from its relatively low melting temperature.

Mutations can disrupt the cell cycle, and can cause certain diseases and conditions.

Answer:  T

Explanation:   In each row, add together the numerical values of the pairs of letters to the left and right, then calculate their difference, putting the letter with this numerical value in the centre space.