JSS 2 Basic Science Objective Questions Quiz: Are You Prepared?

The lightest known element is hydrogen because it has atomic number 1 and usually an atomic mass close to 1. This means each hydrogen atom contains just one proton and, in its most common form, no neutrons. Oxygen, chlorine, and carbon all have more protons and neutrons, giving them higher atomic masses. Therefore, among the options, hydrogen is the lightest element and the correct answer.

HIV is transmitted through contact with certain body fluids such as blood, semen, vaginal fluid, and breast milk from an infected person. Unsafe sex without condoms allows direct exchange of these fluids, making it a major route of infection. Handshakes, insect bites, and simply sharing a bed do not involve this kind of fluid exchange, so they are not recognized routes of HIV transmission. Hence unsafe sex is correct.

Proteins are large molecules made from chains of amino acids. In the digestive system, enzymes such as pepsin in the stomach and trypsin in the small intestine break proteins down step by step into smaller peptides and finally into individual amino acids. These amino acids are then absorbed into the bloodstream and used to build new proteins. Uric acid, fatty acids, and citric acid come from different biochemical processes, not protein digestion.

When water boils, it changes from liquid to gas, forming steam at its boiling point. However, the chemical composition remains H₂O before and after boiling. Because no new substance is formed, this process is classified as a physical change. Biological changes involve living processes, magnetic changes involve magnetism, and chemical changes create new substances. So boiling water is a physical change rather than a chemical or biological one.

Water-borne diseases are transmitted through drinking or using water contaminated with pathogens. Dysentery, cholera, and typhoid typically spread when people consume water or food contaminated with fecal matter containing bacteria or parasites. Measles, however, spreads mainly through droplets in the air when an infected person coughs or sneezes. It does not require contaminated water for transmission, so it is not classified as a water-borne disease, making measles the correct choice.

White blood cells, or leukocytes, are specialized cells of the immune system. They detect, attack, and destroy invading pathogens such as bacteria, viruses, and parasites. Different types of white blood cells have different roles, including producing antibodies or engulfing germs. Red blood cells mainly transport oxygen, bone cells maintain skeletal structure, and there is no such thing as water cells. Therefore, white blood cells are the cells that fight germs in the body.

Water pollution occurs when harmful substances like refuse, sewage, and oil enter rivers, lakes, or oceans. Refuse adds solid waste, sewage introduces organic matter and pathogens, and oil spillage forms films that harm aquatic life. Oxygen dissolved in water is essential for fish and other organisms to breathe. Higher oxygen levels generally improve water quality, so oxygen is not a pollutant and is correctly identified as not causing water pollution.

Crude oil is a naturally occurring liquid fossil fuel formed from ancient organic matter. Chemically, it consists mainly of hydrocarbons, which are compounds made only of hydrogen and carbon atoms. These hydrocarbons vary in chain length and structure, giving different fractions like petrol, kerosene, and diesel when refined. Stone, gravel, and sand are inorganic earth materials; they are not the main components of crude oil. Therefore, hydrocarbons is the correct option.

Carbohydrates such as starch are broken down by digestive enzymes into smaller sugars. Salivary amylase and pancreatic amylase first convert starch into maltose and other disaccharides. Then enzymes in the small intestine further break these into glucose molecules. Glucose is the main simple sugar absorbed into the bloodstream and used as a quick source of energy. Amino acids and fatty acids come from protein and fat digestion, so glucose is the correct end product.

A thermometer is specifically designed to measure temperature. Traditional liquid-in-glass thermometers use mercury or colored alcohol, which expands as temperature increases and contracts as it decreases, moving along a numbered scale. A barometer measures atmospheric pressure, a hydrometer measures relative density of liquids, and a hygrometer measures humidity in air. Therefore, among the listed instruments, the thermometer is the correct one used for measuring temperature.

Reproduction is the biological process by which living organisms produce new individuals of the same kind. It can be sexual, involving fusion of male and female sex cells, or asexual, where one parent produces genetically similar offspring. Digestion concerns breaking down food, menstruation is part of the female reproductive cycle but not the entire process of producing offspring, and production is too general a term. Therefore, reproduction is the precise scientific term required.

Gravity is the attractive force that masses exert on each other. The Earth’s gravity pulls objects toward its center, causing things to fall when dropped. Weight is the measure of this gravitational force acting on a mass, but the wording “force with which the earth attracts objects” refers directly to gravity as the phenomenon. Mass describes the amount of matter, and force is a general term. Therefore, gravity is the best choice.

Heat can be transferred by conduction, convection, or radiation. Conduction occurs through direct contact in solids, convection through the movement of fluids, and radiation through electromagnetic waves without the need for a medium. Insulation, on the other hand, is a method for reducing or slowing down heat transfer. Insulating materials such as foam or wool resist heat flow rather than transferring it, so insulation is not itself a heat-transfer process.

Habitats are natural environments where organisms live. Aquatic habitats are water-based, arboreal habitats are tree-based, and terrestrial habitats are land-based. Ecology, however, is the scientific study of how organisms interact with each other and their environments; it is a field of study, not a physical place where organisms live. Therefore, ecology is not a type of habitat and is correctly chosen as the exception in this question.

ROYGBIV is a mnemonic for the sequence of colors in the visible spectrum: Red, Orange, Yellow, Green, Blue, Indigo, Violet. Each letter represents the first letter of a color. The letter I stands for indigo, a deep blue-purple color. Indices and index are mathematics terms, while iodine is a chemical element. None of those are colors in the spectrum, so indigo is the only correct choice here.

Kwashiorkor is a severe form of protein-energy malnutrition, often seen in children whose diets are high in carbohydrates but very low in protein. Symptoms include swollen belly, skin changes, and stunted growth. Scurvy results from vitamin C deficiency, beriberi from vitamin B₁ deficiency, and headache is a symptom with many possible causes, not specifically linked to protein deficiency. Therefore, kwashiorkor is the disease caused by lack of protein.

The classical three states of matter are solid, liquid, and gas. In a solid, particles are closely packed; in a liquid, they can move but stay close; in a gas, they are far apart and move freely. Space itself is not a state of matter; it describes the emptiness or region where matter and energy may exist. Thus, space does not belong with the states of matter and is the correct answer.

A forest is a large area covered mainly with trees and undergrowth. It supports a wide range of plants and animals and plays important roles in climate regulation and oxygen production. A habitat is any environment where an organism lives and can be large or small. Shrubs are small woody plants, and a shed is a small man-made structure. Since the question describes a tree-thick land area, forest is the correct choice.

The World Health Organization, abbreviated WHO, is an agency of the United Nations responsible for international public health. It coordinates responses to disease outbreaks, provides guidance on health standards, and helps countries strengthen their health systems. UNICEF focuses on children’s welfare, UNESCO on education, science, and culture, and NMA is usually a national medical association. WHO’s global health mandate makes it the correct organization for preventing and controlling major diseases.

Rubber is a good electrical insulator because it has very high resistance to the flow of electric current. Its electrons are tightly bound and do not move freely, so electricity does not pass easily through it. Conductors like metals allow current to flow, electrodes are conducting parts used in circuits, and opaque describes how light passes, not electricity. Therefore, rubber is best described as an insulator in the context of this question.

Mammals are warm-blooded vertebrates that usually have hair or fur, give birth to live young, and feed them with milk from mammary glands. Goats, humans, and whales all meet these criteria, even though whales live in water. Fish, however, lay eggs in most cases, do not have mammary glands, and have scales instead of hair. Thus, fish do not belong to the mammal group and are correctly identified as the exception.

The solar system is centered on the sun and includes the planets that orbit it, along with their moons, asteroids, and other bodies. Saying “sun and planets” captures this main structure correctly. The sun and moon describe only Earth’s satellite, sun and earth exclude the other planets, and sun and stars would describe a galaxy or star cluster rather than a single solar system. Therefore, sun and planets is the best description.

The sun is the primary natural source of energy for life on Earth. It provides light and heat, drives photosynthesis in plants, and powers weather and climate systems. Human energy sources such as fossil fuels and biomass originally come from solar energy stored by plants. The moon and other planets reflect sunlight but do not generate significant energy for Earth. Therefore, among the options, the sun is the primary energy source for humans.

Eggs, beans, and fish are all rich in protein and are common sources of this nutrient in many diets. Rice contains some protein but mainly provides carbohydrates and is not considered a high-protein food compared with the others listed. In a question asking which does not contain protein in the same sense as the others, rice stands out as the item with comparatively low protein content, so it is correctly chosen as the exception.

A barometer measures atmospheric pressure. In a mercury barometer, air pressure pushes on a reservoir of mercury, causing the column height to rise or fall. This height indicates pressure. A hydrometer measures relative density of liquids, a thermometer measures temperature, and a potentiometer is an electrical instrument to measure potential difference or calibrate voltages. Only the barometer is designed specifically for atmospheric pressure, so it is the correct option here.

Reptiles are cold-blooded vertebrates with dry, scaly skin, such as snakes, lizards, and crocodiles. They usually lay eggs with leathery shells on land. Fish live in water and have gills, birds have feathers and wings, and goats are warm-blooded mammals with hair and mammary glands. Among the options, only the lizard fits the definition of a reptile, so lizard is the correct answer in this question.

Many medicines come from natural sources like medicinal leaves, plant bark, roots, and shrubs. These plant parts contain active chemical compounds that can treat diseases or symptoms. Food materials, although nutritious, are not normally categorized as primary sources of drug substances in basic science. They may support health but are not themselves typical drug sources in this context. Therefore, food materials is the correct exception among the options given.

Sensitivity is the ability of an organism to detect and respond to changes in its environment, called stimuli. For example, plants turning toward light and humans pulling a hand away from a hot surface show sensitivity. Irritability is sometimes used synonymously in older texts, but sensitivity is the clearer modern term. Excretion removes wastes, and growth is an increase in size or number of cells. Thus, sensitivity best matches the definition.

Steel is an alloy mainly composed of iron with a controlled amount of carbon, usually up to about two percent by mass. The carbon strengthens the iron by changing its crystal structure and limiting dislocation movement, improving hardness and strength. Zinc forms alloys like brass with copper, gold forms jewelry alloys, and lead is used in other specialized alloys. None of these are the primary alloying element in common steel, so carbon is correct.

A fracture is the medical term for a break or crack in a bone. It can range from a small hairline fracture to a complete break with displacement. Structure describes how something is arranged, a sore is a painful area of tissue damage often on the skin, and a burn is injury caused by heat or chemicals. Since the question focuses specifically on a broken bone, fracture is the accurate and correct term.

Common methods of drug use include smoking, injecting, swallowing, inhaling, or even applying via skin in some medical forms. Tattooing can occasionally introduce substances into the body but is not a standard or recognized method for taking drugs in basic health education. Cutting is self-injury rather than drug administration. Among the options, cutting clearly does not represent a method of drug use, so it is the correct answer.

The female sex cell, or ovum, is produced in the ovaries. Each ovary contains follicles where eggs develop and mature before being released during ovulation. The bladder stores urine and has no reproductive role, the testis produces male sex cells (sperm), and the vagina is part of the birth canal and receives sperm but does not produce eggs. Therefore, the organ that produces the female sex cell in mammals is the ovary.

Smoking is one of the oldest methods of preserving food, particularly meat and fish. The smoke partially dries the food and deposits chemicals that slow bacterial growth, extending shelf life. Bottling and canning are more modern techniques that rely on sealing and heat treatment, while refrigeration depends on electric cooling technology. Because the question asks specifically for an old method, smoking is the best match among the options.

Vaccines exist for tuberculosis, polio, and measles, all of which can cause serious illness but are preventable through immunization programs. Headache is a symptom that can result from many different causes and does not correspond to a single infectious disease for which a vaccine is given. Because you cannot immunize specifically against “headache” as a disease, it is correctly identified as the option that cannot be immunized against.

Elements of weather describe atmospheric conditions and include temperature, humidity, rainfall, wind, and air pressure. These factors change daily and can be measured to describe the weather. Waves are movements of water, primarily seen in oceans and lakes, and while wind can influence them, they are not considered a direct atmospheric element in weather reports. Therefore, wave does not belong with the listed weather elements and is the correct exception.

Filtration, decantation, and distillation are all methods used to separate components of mixtures. Filtration separates insoluble solids from liquids, decantation separates a liquid from settled solids or two immiscible liquids, and distillation separates liquids based on different boiling points. Titration, instead, is an analytical technique used to determine the concentration of a solution by reacting it with a solution of known concentration, not primarily for separating components. Therefore titration is not a separating technique.

A dry cell battery stores chemical energy in the form of reactants inside its electrodes and electrolyte. When connected in a circuit, a chemical reaction occurs that moves electrons through the external circuit, supplying electrical energy to devices. It does not store solar, nuclear, or sound energy. Those forms of energy are produced or captured in different ways, so chemical energy is the correct description for a dry cell’s stored energy.

Veins carry blood from the tissues back to the heart, usually low in oxygen and under lower pressure. Arteries carry blood away from the heart to different parts of the body, usually rich in oxygen and under higher pressure due to the pumping action of the heart. So, the pair that correctly describes vessels to and from the heart respectively is veins and arteries.

Non-degradable materials do not easily break down by natural processes such as bacterial action or weathering. Polythene bags, broken bottles, and rusty iron plates persist in the environment for many years, creating pollution. Dead animals, however, are organic and can be decomposed by microorganisms into simpler substances, returning nutrients to the soil. Therefore, dead animals are not non-degradable, making that option the correct exception.

Growth and development in humans and other organisms are strongly influenced by genetics, nutrition, and environment. Genes determine inherited traits and potential, nutrition supplies the materials and energy for building body tissues, and environment includes conditions such as health care, climate, and family background. Enzymes are important biological catalysts but, by themselves, are not classified as main external or general factors influencing growth and development, so enzyme is the correct exception.

The cell is considered the structural and functional unit of life because every living organism is made of one or more cells. Cells perform essential functions such as respiration, excretion, growth, and reproduction. Tissues, organs, and systems are formed by groups of cells working together, but they are higher levels of organization. Without cells, none of these structures or life processes could exist, so cell is the fundamental unit.

The expression mass × acceleration due to gravity × height (mgh) gives gravitational potential energy. It represents the energy an object has because of its position in a gravitational field. If the object falls, this stored energy can be converted into kinetic energy. Mechanical energy is a broader term that includes both kinetic and potential energy together, but the formula specifically represents potential energy, so that option is correct.

Isolation rules are designed to reduce spread by keeping infected people away from others until they are unlikely to be contagious. Many health guidelines have used a minimum period around ten days from symptom onset or from a positive test for mild cases, with extra days after symptoms improve. Among the options given, ten days is the closest to these recommended minimum periods, so it is accepted as the correct answer in this quiz.

Vectors are living organisms that transmit disease-causing microorganisms from one host to another. Mosquitoes transferring malaria parasites and ticks spreading Lyme disease are classic examples. Germs are the microorganisms themselves, antibodies are defensive proteins produced by the immune system, and carriers are infected individuals who may show no symptoms yet still transmit disease. The term that specifically means a living carrier of pathogens is vectors, so that option is correct.

The pelvic girdle consists of the hip bones, which attach the lower limbs to the axial skeleton. It forms a strong basin-like structure that supports the weight of the upper body when standing or walking and protects organs in the pelvic cavity, such as parts of the intestine and reproductive organs. It is not located in the head, neck, or wrist, so the correct location for the pelvic girdle is the hip region.

A ball and socket joint allows movement in almost all directions because a spherical head of one bone fits into a rounded socket of another. This structure permits flexion, extension, abduction, adduction, and rotation. The shoulder and hip are classic examples. Pivot joints allow rotation only, hinge joints allow movement mainly in one plane like a door, and slightly movable joints have limited motion. Thus, the ball and socket joint best matches the description.

Work is done when a force causes an object to move through a distance in the direction of the force. Mathematically, work equals force multiplied by distance. Energy is the capacity to do work, power is the rate of doing work, and pressure is force acting on a unit area. Because the question focuses on what happens when a force actually moves through a distance, the correct concept is work.

The liver produces bile, a yellowish-green fluid that helps digest fats. Bile is stored in the gallbladder and released into the small intestine, where it emulsifies fats into tiny droplets, increasing the surface area for digestive enzymes. Gastric juice is produced in the stomach, pancreatic juice comes from the pancreas, and the gallbladder only stores bile; it does not secrete it. Thus, the secretion from the liver itself is bile.

Sense organs receive stimuli and send signals to the brain. The eye detects light for vision, the nose detects chemicals for smell, and the skin contains receptors for touch, temperature, and pain. Hair itself is mostly dead keratin and does not process sensory information; it may move with air or touch, but the actual receptors are in the skin. Therefore, hair is not classified as a sense organ and is the correct answer.

The human brain is generally described as having three major parts: the cerebrum, cerebellum, and brainstem. The cerebrum controls higher functions such as thinking and memory, the cerebellum coordinates movement and balance, and the brainstem regulates vital processes like breathing and heartbeat. While the brain can be subdivided further in advanced study, in basic science we refer to these three main parts, so three is the correct answer.