Importance of nucleus is in control of heredity. This fact was proved by experimenting on -

Options

A. Orchid roots
B. Mammalian RBC
C. Sieve tube cells
D. Acetabularia

Answer

**Step-by-Step Solution:**

1. **Understanding the Role of the Nucleus**: The nucleus is often referred to as the control center of the cell because it houses the genetic material (DNA) that is responsible for heredity. It regulates gene expression and mediates the replication of DNA during the cell cycle.

2. **Historical Experiments**: The importance of the nucleus in controlling heredity was demonstrated through various experiments, notably the work of scientists like Gregor Mendel and later experiments involving cell biology.

3. **Hemalynx Nucleocytoplasmic Experiment**: One significant experiment that highlighted the role of the nucleus in heredity is the Hemalynx nucleocytoplasmic experiment. This experiment showed that the nucleus is crucial for the transmission of genetic information.

4. **Acetabularia Experiment**: Another important experiment was conducted using the unicellular green algae called Acetabularia. In this experiment, scientists observed that when the nucleus of Acetabularia was removed and replaced with a nucleus from another species, the resulting organism exhibited traits of the donor nucleus, thereby proving that the nucleus controls heredity.

5. **Conclusion**: The experiments on Acetabularia and the Hemalynx nucleocytoplasmic experiment collectively provide strong evidence that the nucleus is essential for controlling heredity.