Phototropic is an adjective.
No, they are positively phototropic as they grow towards light.
No,
Light-seeking.
a flower is phototrophic because it is moving toward the sun
Phototropic is a word to describe if the plant moves towards light sources or away from light sources. Positively phototropic means it moves towards light. Most, perhaps all, plants will grow towards a light source. Plants need light energy so they have evolved to grow in the direction of the best light. Negatively phototropic means it moves away from light. Vampires are known to be negatively phototropic.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
it grows towards the light.
The part of speech for "unfamiliar" is an adjective.