The scientist who discovered the cell nucleus was: MCQ with Answer and Explanation

Explanation:
Gene therapy involves correcting a genetic defect by introducing a functional gene into a patient's cells. The first clinical gene therapy was given in 1990 to a 4-year-old girl with Adenosine Deaminase (ADA) deficiency, a severe combined immunodeficiency (SCID) caused by a mutation in the ADA gene. The functional ADA gene was introduced into her lymphocytes using a retroviral vector.

Explanation:
Parkinson's disease is a neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the substantia nigra region of the brain. This leads to motor symptoms like tremors, rigidity, and bradykinesia. L-DOPA (levodopa), a precursor of dopamine, is used in treatment. Acetylcholine is related to Alzheimer's, serotonin to depression.

Explanation:
Alexandre Yersin, a Swiss-French bacteriologist, discovered Yersinia pestis in 1894 during the Hong Kong plague epidemic. Koch discovered TB, Pasteur developed vaccines.