who introduced the idea of growing plants in soil-free and defined mineral solution ?

Options

A. Juiius von Sachs
B. Joseph Priestley
C. Melvin-Calvin
D. Malpighi

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the scientist who introduced the idea of growing plants in a soil-free and defined mineral solution.

2. **Recall Relevant Information**: The concept of growing plants without soil is known as hydroponics. This method relies on nutrient solutions to provide the necessary minerals for plant growth.

3. **Research the Key Scientist**: The scientist associated with this idea is Julius von Sachs. He conducted research in the 19th century that focused on the role of photosynthesis and the nutrient requirements of plants.

4. **State the Year of Introduction**: Julius von Sachs introduced his theory in the year 1868. His work demonstrated that plants could thrive in a nutrient-rich solution without the need for soil.

5. **Differentiate Between Other Scientists**: While other scientists like Joseph Priestley, Melvin Calvin, and Malpighi contributed significantly to plant biology, their work focused on different aspects such as gas exchange, photosynthesis pathways, and anatomy, respectively.

6. **Conclude the Answer**: Therefore, the correct answer to the question is Julius von Sachs.

**Final Answer**: Julius von Sachs introduced the idea of growing plants in a soil-free and defined mineral solution in 1868.

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