Which of the following represents a form of potential energy?

Correct Answer: C

Rationale: A raised hammer represents potential energy as it possesses stored energy due to its position above the ground. When the hammer falls, this potential energy is converted into kinetic energy as it moves. In contrast, options A, B, and D involve objects already in motion, representing kinetic energy. Choice A, a moving car, is in motion and has kinetic energy. Choice B, a spinning top, is also in motion and exhibits kinetic energy. Choice D, a rolling ball, is already moving and thus has kinetic energy. Therefore, only choice C, a raised hammer, is the correct representation of potential energy among the given options.

Correct Answer: C

Rationale: Antibodies are proteins produced by specialized white blood cells called B lymphocytes (B cells). These B cells mature in the bone marrow, where they undergo a process of differentiation and maturation to become plasma cells that secrete antibodies. The bone marrow is the primary site for the production of B cells and antibodies in the immune system. The thymus gland is responsible for the maturation of T lymphocytes (T cells), not antibody production. The spleen and lymph nodes play roles in filtering and trapping pathogens but are not the main organs responsible for producing antibodies.

Correct Answer: A

Rationale: Rationale: A) To protect the body from harm: The skin acts as a physical barrier that protects the body from external threats such as pathogens, UV radiation, and physical injuries. It helps prevent infections and dehydration, making it a crucial function of the skin. B) To regulate body temperature: While the skin does play a role in regulating body temperature through processes like sweating and vasodilation/vasoconstriction, its primary function is protection. C) To produce hormones: Hormone production is primarily carried out by endocrine glands such as the pituitary gland, thyroid gland, and adrenal glands, not the skin. D) To sense touch, temperature, and pain: The skin contains sensory receptors that allow us to perceive touch, temperature, and pain, but this function is secondary to its main role of protecting the body from harm.

Correct Answer: B

Rationale: Ketones contain a carbonyl functional group, which consists of a carbon atom double-bonded to an oxygen atom. This distinguishes ketones from other functional groups such as hydroxyl, ester, and amine. The presence of the carbonyl group, not hydroxyl (choice A), ester (choice C), or amine (choice D), is characteristic of ketones, making choice B, 'Carbonyl', the correct answer.

Correct Answer: A

Rationale: Transverse waves are characterized by particles moving perpendicular to the direction of wave propagation. In transverse waves, the oscillations of particles are perpendicular to the direction of energy transfer. Longitudinal waves have particles that move parallel to the direction of wave propagation. Electromagnetic waves are a type of transverse wave that do not require a medium for propagation. Surface waves combine both longitudinal and transverse motions and occur at the interface between two different mediums.