The neurotransmitter that is deficient in Parkinson's disease is: MCQ with Answer and Explanation

Explanation:
Meselson and Stahl proved that after replication, each daughter DNA contains one parental and one newly synthesized strand. R exactly explains semiconservative.

Explanation:
The medulla oblongata is the lowest part of the brainstem, connecting the pons to the spinal cord. It contains vital autonomic centers that control essential, involuntary life-sustaining functions. These include the cardiovascular center (regulating heart rate and blood vessel diameter), the respiratory center (regulating the rate and depth of breathing), and reflex centers for vomiting, coughing, sneezing, and swallowing. Damage to the medulla is often fatal due to the cessation of these vital functions.

Explanation:
The pollen grain contains the male gametophyte, which produces two sperm cells. The ovule contains the female gametophyte (embryo sac). Endosperm is the triploid nutritive tissue formed after double fertilization.