Protection of internal organs Explanation: The main function of the skeletal system in the human body is to provide support, structure, and protection to the internal organs. The bones of the skeleton act as a framework and protect vital organs like the brain, heart, and lungs.

Mixing vinegar and baking soda Explanation: Mixing vinegar and baking soda is an example of a chemical reaction that absorbs heat. In this reaction, vinegar (acetic acid) reacts with baking soda (sodium bicarbonate) to produce carbon dioxide gas, water, and a compound called sodium acetate. This reaction is endothermic, meaning it absorbs heat from the surroundings.

Rubber Explanation: Rubber is an example of an insulator. Insulators are materials that do not easily allow the flow of electric current. Rubber has high electrical resistance, which makes it suitable for insulating wires and providing electrical safety.

Radioactivity Explanation: Radioactivity is the process by which an unstable atomic nucleus releases energy in the form of radiation. This can occur through radioactive decay, where the nucleus undergoes spontaneous changes, emitting alpha particles, beta particles, or gamma rays.

Newton Explanation: The SI unit for measuring the force of gravity is the newton (N). It is named after Sir Isaac Newton and is used to quantify the force exerted by an object due to gravity.

Controls voluntary movements Explanation: The cerebrum is responsible for controlling voluntary movements, processing sensory information, and higher cognitive functions such as thinking, memory, and language.

Nuclear fusion Explanation: The primary source of energy in the Sun is nuclear fusion, where hydrogen atoms combine to form helium, releasing an enormous amount of energy in the process.

Exchange of oxygen and carbon dioxide Explanation: The main function of the respiratory system in the human body is to facilitate the exchange of oxygen and carbon dioxide between the body and the environment. This occurs through breathing, where oxygen is inhaled into the lungs and carbon dioxide is exhaled out of the body.

Produces and releases hormones Explanation: The endocrine system in the human body is responsible for producing and releasing hormones. These hormones act as chemical messengers and regulate various processes in the body, including growth, metabolism, reproduction, and mood.

Evolution Explanation: Evolution is the process by which an organism changes and develops over time to adapt to its environment. It involves genetic changes that occur through natural selection, mutation, and genetic recombination, leading to the development of new species and variations within a population.

Decibel. The decibel (dB) is the SI unit used to measure sound intensity, which refers to the amount of sound energy passing through a given area in a specific time. It is a logarithmic unit that compares the intensity of a sound to a reference level and is commonly used to express the loudness of sounds.

Biomass Explanation: Biomass is a renewable source of energy derived from organic matter, such as plants, wood, agricultural waste, or dedicated energy crops. It can be burned directly or converted into other forms of energy, such as biofuels or biogas.

Performs photosynthesis Explanation: Chloroplasts are responsible for performing photosynthesis in plant cells. They contain chlorophyll, which captures sunlight energy to convert carbon dioxide and water into glucose (food) and release oxygen.

Transportation of nutrients and oxygen Explanation: The main function of the circulatory system in the human body is to transport nutrients, oxygen, hormones, and other substances to various cells and tissues. It does so by circulating blood, which is pumped by the heart through a network of blood vessels.

The correct answer is Absorbs harmful ultraviolet (UV) radiation. The ozone layer is a region of the Earth's stratosphere that contains a high concentration of ozone molecules (O3). It plays a critical role in protecting life on Earth by absorbing most of the Sun's harmful UV radiation, preventing it from reaching the surface. This helps to reduce the risks of skin cancer, cataracts, and damage to ecosystems.

Converts sunlight into chemical energy Explanation: Chloroplasts are responsible for converting sunlight into chemical energy through the process of photosynthesis. They contain a pigment called chlorophyll, which captures light energy and uses it to convert carbon dioxide and water into glucose and oxygen.

Produces energy Explanation: Mitochondria are often referred to as the powerhouse of the cell because their main function is to produce energy through cellular respiration. They convert nutrients, such as glucose, into adenosine triphosphate (ATP), which serves as the primary energy source for the cell.

Synthesizes proteins Explanation: Ribosomes are responsible for protein synthesis in a cell. They read the genetic information contained in messenger RNA (mRNA) and assemble amino acids in the correct order to form proteins.

The correct answer is  Photosynthesis. Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy from the sun into chemical energy stored in glucose. This process takes place in the chloroplasts of plant cells and involves the capture of light energy, the synthesis of glucose, and the release of oxygen as a byproduct.

Ionization Explanation: Ionization is the process by which an atom gains or loses electrons, resulting in a charged particle called an ion. It occurs when atoms interact with other atoms, molecules, or external energy sources, causing the transfer of electrons and the formation of positively or negatively charged ions.

The correct answer is  Modifies and packages proteins. The Golgi apparatus is responsible for modifying, sorting, and packaging proteins and lipids that are synthesized in the cell. It consists of a series of flattened membrane sacs called cisternae, and its function is crucial for the transport and delivery of molecules within the cell and to other parts of the organism.

Digestion. Explanation: Digestion is the process by which an organism converts food into usable energy. It involves the breakdown of complex food molecules into smaller, simpler molecules that can be absorbed and utilized by the body. The process of digestion occurs in multiple steps, starting from the mechanical and chemical breakdown of food in the mouth, followed by the passage of food through the esophagus into the stomach.

Iron Explanation: Iron is the main component of the Earth's core. The core is divided into an outer core and an inner core, both primarily composed of iron and nickel. The intense heat and pressure in the core maintain it in a liquid and solid state, respectively.

Wave-particle duality Explanation: Wave-particle duality is the phenomenon where light and other particles, such as electrons, exhibit both wave-like and particle-like properties. It means that they can behave as waves with characteristics like diffraction and interference, as well as particles with characteristics like position and momentum.

Filtration of waste products from the blood Explanation: The kidneys in the human body play a crucial role in filtering waste products from the blood and regulating the body's fluid balance. They remove excess water, toxins, and metabolic waste from the bloodstream and produce urine as a waste product.