Solution:

• Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom.
• Alkaloids have diverse and important physiological effects on humans and other animals.
• Well-known alkaloids include morphine, strychnine, quinine, ephedrine, and nicotine.
• Caffeine is xanthine alkaloid that occurs naturally in seeds, leaves and fruit of several plants and trees that acts as a natural pesticide.
• Caffeine is a major component of coffee, tea and chocolate and in humans acts as a central nervous system (CNS) stimulant.