The behaviour of chromosomes was parallel to behaviour of genes and used chromosomal movement to explain

Options

A. Meiosis
B. Mendel's law
C. Chromosomes
D. Chromosomal theory of inheritance

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question states that the behavior of chromosomes parallels the behavior of genes and asks which concept explains this chromosomal movement.

2. **Identifying the Theory**: The concept that explains the parallel behavior of chromosomes and genes is the **Chromosomal Theory of Inheritance**. This theory was proposed by scientists Sutton and Boveri.

3. **Mendel's Contribution**: Gregor Mendel conducted experiments on pea plants (Pisum sativum) and formulated the laws of inheritance based on his observations of how traits are passed from parents to offspring. He introduced the idea of "factors" (now known as genes) that control traits.

4. **Chromosomes and Genes**: Mendel's factors were later understood to be genes located on chromosomes. The Chromosomal Theory of Inheritance states that the behavior of chromosomes during cell division (meiosis) is analogous to the behavior of genes during inheritance.

5. **Law of Segregation**: Mendel's Law of Segregation states that during the formation of gametes, the two alleles for a trait separate from each other. This is mirrored in the behavior of chromosomes, where homologous chromosomes separate during meiosis.

6. **Conclusion**: The Chromosomal Theory of Inheritance explains that the movement and segregation of chromosomes during cell division correspond to the segregation of alleles as described by Mendel. Thus, this theory can be used to verify and explain Mendel's laws of inheritance.

### Final Answer:
The Chromosomal Theory of Inheritance explains that the behavior of chromosomes is parallel to the behavior of genes and can be used to verify Mendel's laws of inheritance.

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