Explanation: Groundnut (Arachis hypogaea) is a leguminous plant that exhibits geocarpy — after fertilization a downward-growing peg pushes the fertilized ovary into the soil and the pod (the fruit) matures below ground. Potato, carrot and onion are underground plant parts but are respectively a tuber (stem), root and bulb — not fruits.

The electron was discovered by J. J. Thomson in 1897 during his experiments with cathode rays. He demonstrated that cathode rays are composed of tiny negatively charged particles, which he named electrons. This discovery revolutionized atomic theory and led to the development of the plum pudding model of the atom, where electrons are embedded in a positively charged sphere.

Other options (for context)

• Enrico Fermi: Known for his work on nuclear physics and the development of the first nuclear reactor.
• Robert Noyce: Co-inventor of the integrated circuit (microchip).
• James Dyson: Inventor of the modern vacuum cleaner, not a physicist.

Explanation: Natural gas is not a renewable source of energy because it is a fossil fuel formed over millions of years from the remains of plants and animals. Once used, it cannot be replenished quickly. In contrast, geothermal energy, flowing water, and biomass are renewable energy sources that can be naturally regenerated.

Explanation: Marijuana is a psychoactive drug obtained from the female inflorescence (flowering tops) of the Cannabis sativa plant. It contains the active compound tetrahydrocannabinol (THC), which affects the central nervous system and alters mood and perception.

Explanation: Acupuncture is an ancient form of traditional Chinese medicine that involves the insertion of very thin needles through the skin at specific points, called acupoints. It is based on the concept of balancing the flow of life energy (Qi or Chi) through pathways in the body known as meridians. When these energy flows are blocked or imbalanced, it can cause illness or pain.

By stimulating specific acupoints, acupuncture is believed to restore the normal energy flow and help the body heal itself. It is commonly used to treat:

• Chronic pain (e.g., back, neck, and joint pain)
• Migraines and headaches
• Arthritis and muscle stiffness
• Stress and anxiety

Scientific View: Modern research suggests that acupuncture may stimulate nerves, muscles, and connective tissue, boosting the body’s natural painkillers (endorphins).

Explanation: Smallpox is a highly contagious and deadly disease caused by the Variola virus. It is characterized by high fever, fatigue, and a distinctive pustular rash on the skin. Smallpox was one of the most devastating diseases in human history, but thanks to the worldwide vaccination campaign led by the World Health Organization (WHO), it was officially eradicated in 1980. The vaccine for smallpox was first developed by Edward Jenner in 1796.

Explanation: Natural gas is a non-renewable source of energy because it is formed from fossilized organic matter over millions of years and cannot be replenished quickly. In contrast, geothermal energy, flowing water, and biomass are renewable as they can be naturally regenerated over short periods.

Explanation: Cobalt-60 (Co-60) is a radioactive isotope of cobalt that emits high-energy gamma rays during its decay process. It decays into Nickel-60 (Ni-60) by beta decay, releasing two strong gamma photons of energies 1.17 MeV and 1.33 MeV. Due to these intense gamma emissions, Co-60 is widely used in radiation therapy (teletherapy) for cancer treatment, as well as in industrial radiography and sterilization of medical equipment. Gamma rays have high penetration power, allowing them to destroy cancerous cells deep inside tissues.