What was the most significant conclusion that Gregor Mendel drew from his research?

Options

A. There is considerable genetic variation in garden peas.
B. An organism that is homozygous for many recessive traits is at a disadvantage
C. Genes are composed of DNA
D. Factors for the development of traits are inherited in discrete units, one from each parent

Answer

### Step-by-Step Solution:

1. **Understanding Mendel's Research**: Gregor Mendel conducted experiments on pea plants (Pisum sativum) to study inheritance patterns. He focused on how traits were passed from one generation to the next.

2. **Identifying Key Findings**: Mendel's experiments led him to observe that traits are inherited in specific patterns. He noted that certain traits appeared consistently in offspring, which suggested a systematic way of inheritance.

3. **The Concept of Discrete Units**: One of Mendel's most significant conclusions was that traits are inherited in discrete units, which he referred to as "factors" (now known as genes). This means that each parent contributes one factor for each trait.

4. **The Principle of Segregation**: Mendel discovered that during the formation of gametes (egg and sperm), the two copies of each gene (one from each parent) segregate so that each gamete carries only one copy. This is known as the Law of Segregation.

5. **Conclusion**: The most significant conclusion drawn by Mendel from his research is that traits are inherited in discrete units (factors), one from each parent, which laid the foundation for the field of genetics.

### Final Answer:
The most significant conclusion that Gregor Mendel drew from his research is that traits are inherited in discrete units (now called genes), with one unit coming from each parent.

---