Question

Which scientist thought he proved that plants obtain nutrients from water rather than soil?

Which scientist demonstrated that the green parts of plants absorb carbon dioxide and release oxygen only in sunlight?
Which scientist showed that plants use red and blue light in photosynthesis?

Answer 1

1). van Helmont
2). Igenhousz
3) Englemann

Answer 2

1. Van Helmont conducted an experiment in which he weighed a willow tree and also weight the mass of dry soil. He then planted theow will tree, kept watering it for next five years and then reweighed it at the end of five years. He observed that tree has gained weight by some 12 stones. Thus he proved that plants obtain nutrients from water rather than soil

2. Ingenhousz is acclaimed for discovering the process of photosynthesis in plants. He was the first to observe that when plant are kept in light, oxygen gas is released while during night a different kind of gas is released (i.e Carbon Dioxide)

3. Engelmann illustrated that plants use red and blue light during photosynthesis by exposing different parts filamentous algae to different light waves of visible spectrum. He then observed that part of algae exposed to red and blue light produced more oxygen.