Which two organs of a plant interact to cause seedlings to grow upward

There's tropism and stimulus, for starters. Gravity, light, and touch can all be used as stimuli. So it is debatable... If the plant is reaching upwards towards a window that is above it... It would then be light, and the plant's response would be to reach upward.

Hope this helps and if it does, don't be afraid to give my answer a "Thanks" and maybe a Brainliest?  

carbohydrates: (starches and sugars) composed of carbon, hydrogen, and oxygen.

lipids: (fats, oils, and waxes) are made of carbon and hydrogen atoms.

nucleic acids: contain hydrogen, oxygen, nitrogen, carbon, and phosphorus. they are polymers of nucleotides. a nucleotide has three parts, a 5-carbon sugar, a phosphate     (-po⬇️4) group, and a nitrogenous base.

proteins: made up of nitrogen, carbon, hydrogen, and oxygen. they are polymers of amino acids.

dgjnuuk

explanation:

is the dgjofgkg. huukkg u