Jss 2 Basic Science Objective Questions: Are You Prepared?

HIV/AIDS can be transmitted through unsafe sex, which includes engaging in sexual activities without using protection such as condoms. This is because the virus can be present in the bodily fluids of an infected person, such as blood, semen, vaginal fluids, and breast milk. Therefore, engaging in unprotected sexual intercourse with an infected person can lead to the transmission of the virus.

A large area of land that is thickly covered with trees is known as a forest. Forests are characterized by their dense tree cover and are home to a wide variety of plant and animal species. They play a crucial role in maintaining the ecological balance, providing habitats for wildlife, and contributing to the overall health of the planet.

A break in the bone of a man is referred to as a fracture.

Oxygen is not a form of water pollution. Water pollution refers to the contamination of water bodies, such as rivers, lakes, and oceans, by harmful substances or pollutants. Refuse, sewage, and oil spillage are all examples of water pollution as they introduce pollutants into the water, causing harm to the aquatic ecosystem and potentially to human health. Oxygen, on the other hand, is a vital component of water and necessary for the survival of aquatic organisms.

A thermometer is an instrument used for measuring temperature. It consists of a narrow, sealed glass tube filled with a liquid, usually mercury or alcohol, which expands or contracts with changes in temperature. The temperature is indicated by the height of the liquid column inside the tube. A barometer is used to measure atmospheric pressure, a hydrometer is used to measure the density or specific gravity of a liquid, and a hygrometer is used to measure humidity in the air. Therefore, the correct instrument for measuring temperature is a thermometer.

The sun is the primary source of energy for humans. It provides heat and light, which are essential for various life processes on Earth. The energy from the sun is captured by plants through photosynthesis, and then transferred to animals and humans through the food chain. Additionally, solar energy is also harnessed through solar panels to generate electricity for various purposes.

Among the listed food substances, rice is the only one that does not contain a significant amount of protein. Eggs, beans, and fish are all excellent sources of high-quality protein, making them essential components of a protein-rich diet. While rice does provide some protein, it is primarily known for its carbohydrate content and is not regarded as a substantial protein source compared to the other foods mentioned.

The correct answer is (d) lizard. A lizard is a reptile because it has scaly skin, lays eggs, and is cold-blooded. Fish, birds, and goats are not reptiles.

The process by which living organisms produce their kind is called reproduction. This involves the production of offspring, either sexually or asexually, to ensure the continuation of the species. Digestion is the process of breaking down food for energy, menstruation is a specific reproductive process in female mammals, and production is a broad term that can refer to various activities but not specifically the production of offspring.

The World Health Organization (W.H.O) is the world body that is responsible for preventing and controlling major diseases. It is an international organization that works to promote and improve global health, coordinate responses to health emergencies, and provide leadership on issues related to public health. W.H.O plays a crucial role in monitoring and responding to disease outbreaks, developing and implementing health policies, and providing technical assistance and support to countries in need. UNICEF, UNESCO, and NMA are not specifically focused on disease prevention and control, making W.H.O the correct answer.

The correct answer is (c) terrestrial organisms. Terrestrial organisms are animals that live on land, as opposed to aquatic organisms that live in water or arboreal organisms that live in trees. Marsh organisms specifically refer to animals that live in marshes, so they are not a suitable answer for this question.

Space is not considered a state of matter because it is not made up of particles like solids, liquids, and gases. Space is essentially a vacuum, devoid of any matter or particles. While it is true that there are celestial objects and phenomena in space, the space itself is not a state of matter.

Crude oil is a fossil fuel that is formed from the remains of ancient plants and animals. It is composed mainly of hydrocarbons, which are organic compounds made up of hydrogen and carbon atoms. These hydrocarbons can vary in size and structure, resulting in different types of crude oil with varying properties. Therefore, the correct answer is d) hydrocarbons.

Sense organs are organs that receive and process sensory information from the environment. The eye is responsible for vision, the nose is responsible for smell, and the skin is responsible for touch. Hair, on the other hand, is not considered a sense organ as it does not have the ability to receive and process sensory information. Therefore, the correct answer is (b) hair.

Gravity is the force with which the earth attracts objects towards its center. It is responsible for keeping objects on the surface of the earth and giving weight to objects. The force of gravity is directly proportional to the mass of the objects and inversely proportional to the square of the distance between them. Therefore, the correct answer is (c) gravity.

In the acronym ROYGBIV, each letter represents a color in the visible light spectrum. R stands for red, O stands for orange, Y stands for yellow, G stands for green, B stands for blue, I stands for indigo, and V stands for violet. Therefore, the letter I in ROYGBIV stands for the color indigo.

When solids change into liquids at an appropriate temperature, the process is called melting. This occurs when the solid's particles gain enough energy to overcome the forces holding them together in a rigid structure, causing them to break free and move more freely as a liquid. Evaporation refers to the process of a liquid turning into a gas, boiling specifically refers to the rapid formation of bubbles within a liquid due to its vaporization, and diffusion refers to the movement of particles from an area of high concentration to an area of low concentration.

Deficiency of protein causes kwashiorkor in humans. Kwashiorkor is a form of severe protein malnutrition that primarily affects children. It is characterized by symptoms such as swelling, fatigue, loss of muscle mass, and a distended abdomen. This condition occurs when there is a lack of protein in the diet, leading to a deficiency in essential amino acids necessary for growth and development. Scurvy is caused by a deficiency of vitamin C, beriberi is caused by a deficiency of thiamine, and headache can have various causes unrelated to protein deficiency.

The structural and functional unit of life is the cell. Cells are the basic building blocks of all living organisms and are responsible for carrying out all the necessary functions for life. They are capable of reproducing, obtaining nutrients, eliminating waste, and carrying out various metabolic activities. Cells can exist as single-celled organisms or as part of a larger organism, working together to maintain homeostasis and ensure the survival of the organism.

White blood cells, also known as leukocytes, are responsible for fighting off germs and infections in the body. They are a crucial part of the immune system and help to defend against bacteria, viruses, and other harmful pathogens. Red blood cells are responsible for carrying oxygen, bone cells are responsible for maintaining the structure of the bones, and there is no such thing as a "water cell". Therefore, the correct answer is (b) white blood cell.

A ball and socket joint is a type of joint that allows movement in all directions. It consists of a rounded end of one bone (ball) that fits into a cup-like socket of another bone. This joint provides a wide range of motion and allows for movements such as rotation, flexion, extension, abduction, and adduction. Examples of ball and socket joints in the human body include the shoulder and hip joints.

Drugs can be obtained from various sources such as medicinal leaves, plant barks, roots and shrubs. However, food materials do not typically contain substances that can be used as drugs. Therefore, the correct answer is (c) food materials.

Smoking is an old method of preservation where food is exposed to smoke from burning wood or other materials. The smoke acts as a natural preservative by drying out the food and inhibiting the growth of bacteria and other microorganisms. This method has been used for centuries to preserve meats, fish, and other perishable foods. Bottling, canning, and refrigeration are relatively newer methods of preservation compared to smoking.

Headache is not a disease that can be immunized. It is a symptom of various underlying causes such as stress, tension, migraine, or sinus problems. Immunization is the process of providing immunity against specific diseases through vaccines. Tuberculosis, polio, and measles are all diseases that can be prevented through immunization.

Measles is not a water-borne disease because it is primarily transmitted through respiratory droplets from infected individuals. It is caused by a virus and is highly contagious, but it is not spread through contaminated water sources like dysentery, cholera, and typhoid.

The correct answer is (d) enzyme. Enzymes are not factors that directly influence growth and development. Factors such as environment, nutrition, and genetics play significant roles in determining an individual's growth and development. Enzymes, on the other hand, are proteins that facilitate chemical reactions in the body but do not directly impact growth and development.

The pelvic girdle is a set of bones located at the hip. The hip bones, also known as the innominate bones or coxal bones, make up the pelvic girdle and are connected to the sacrum at the back and to each other at the front. The pelvic girdle provides support and stability to the upper body and helps transfer weight from the spine to the lower limbs. It also protects the pelvic organs such as the bladder, reproductive organs, and part of the digestive system.

According to WHO, a coronavirus victim can be isolated for a minimum of 10 days after the onset of symptoms, plus an additional 3 days after symptoms have resolved. For individuals who test positive but are asymptomatic, the isolation period is a minimum of 10 days following the positive test.

The organ which produces the female sex-cell in a mammal is the ovary. The ovary is a part of the female reproductive system and is responsible for producing and releasing eggs, or ova, during the process of ovulation. The ovaries also produce hormones such as estrogen and progesterone, which play a crucial role in regulating the menstrual cycle and supporting pregnancy.

Protein digestion is the process by which proteins are broken down into their individual amino acids. Amino acids are the building blocks of proteins and are essential for various biological processes in the body. Therefore, the end product of protein digestion is amino acids. Uric acid, fatty acid, and citric acid are not the end products of protein digestion.

Fish are not mammals. Mammals are warm-blooded vertebrates that have hair or fur, produce milk to feed their young, and give birth to live young. Fish, on the other hand, are cold-blooded vertebrates that typically have scales and lay eggs. Therefore, fish do not belong to the category of mammals.

A barometer is the instrument used to measure atmospheric pressure. It works by measuring the height of a column of mercury or aneroid barometer, which changes with changes in atmospheric pressure. A hydrometer is used to measure the density or specific gravity of a liquid, a thermometer is used to measure temperature, and a potentiometer is used to measure electrical potential difference. None of these instruments are specifically designed to measure atmospheric pressure, making (a) barometer the correct answer.

Weather refers to the atmospheric conditions at a specific time and place. Rainfall, humidity, and temperature are all elements of weather as they directly affect the state of the atmosphere. However, waves are not considered an element of weather. Waves refer to the movement of water bodies, such as oceans or lakes, and are influenced by factors like wind and tides. While waves can be affected by weather conditions, they are not considered as elements of weather themselves.

Veins are blood vessels that carry blood away from the body's organs and tissues back to the heart. Arteries, on the other hand, carry oxygenated blood away from the heart to the body's organs and tissues. Therefore, veins and arteries are the blood vessels that carry blood to and away from the heart respectively.

Non-degradable materials are those that cannot be broken down or decomposed by natural processes. Polythene bags, broken bottles, and rusty iron plates are all examples of non-degradable materials because they do not break down easily and can persist in the environment for a long time. However, dead animals are biodegradable, meaning they can be broken down by bacteria, fungi, and other organisms. Therefore, dead animals are not an example of a non-degradable material.

Milk contains lactic acid. This acid is produced by bacteria that ferment lactose, a sugar found in milk. Lactic acid gives milk its slightly sour taste and helps in the preservation of milk by preventing the growth of harmful bacteria. Therefore, the correct answer is (c) lactic acid.

Insulation is not a process of heat transfer. Insulation is a method used to prevent or reduce the transfer of heat between objects or areas. It involves using materials with low thermal conductivity to create a barrier that restricts the flow of heat. In contrast, radiation, conduction, and convection are all processes of heat transfer. Radiation is the transfer of heat through electromagnetic waves, conduction is the transfer of heat through direct contact between objects, and convection is the transfer of heat through the movement of fluids.

The solar system consists of the sun, which is a star, and the planets that orbit around it. The sun is the central and most massive object in the solar system, while the planets are smaller celestial bodies that revolve around the sun in elliptical orbits. This arrangement is what defines the structure and dynamics of the solar system.

Rubber is a typical example of an insulator because it does not conduct electricity. Insulators are materials that do not allow the flow of electric current through them easily. Rubber, being a non-metal, has high resistance to the flow of electricity, making it a good insulator.

A dry cell stores chemical energy. This type of battery uses a chemical reaction to generate electricity. The chemicals inside the cell react with each other to produce a flow of electrons, which can be used to power devices. This is different from other types of batteries, such as solar cells, which convert sunlight into electricity, or nuclear cells, which use nuclear reactions to generate power. Sound energy is not stored in a dry cell.

Ecology refers to the scientific study of the relationships between living organisms and their environments, rather than being a specific type of habitat. The other options (aquatic, arboreal, terrestrial) represent different types of habitats: aquatic refers to water habitats, arboreal refers to habitats in trees, and terrestrial refers to habitats on land.

Filtration, decantation, and distillation are all examples of separating techniques used to separate mixtures based on their physical properties such as size, density, or boiling point. Filtration is used to separate solid particles from a liquid or gas by passing it through a porous material. Decantation is the process of separating a liquid from a solid by carefully pouring off the liquid without disturbing the solid. Distillation is a technique used to separate mixtures based on differences in boiling points. Titration, on the other hand, is a technique used to determine the concentration of a substance in a solution by adding a solution of known concentration until the reaction is complete. It is not a technique used for separating mixtures.

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. When water boils, it changes from a liquid to a gas (steam), but its chemical structure (H₂O) remains the same. Other examples of physical changes include melting, freezing, and dissolving. In contrast, a chemical change involves a transformation that alters the chemical identity of a substance, such as burning or rusting.

Mass is the quantity of matter in a body. It is a measure of the amount of material an object contains. Mass is a fundamental property of matter and is independent of its location or the forces acting upon it. It is commonly measured in kilograms or grams.

The secretion from the liver is called bile. Bile is a yellowish-green fluid that is produced by the liver and stored in the gallbladder. It plays a crucial role in the digestion and absorption of fats. Bile is released into the small intestine during digestion to help break down fats into smaller molecules, making them easier to absorb. It also helps in the elimination of waste products from the body, particularly bilirubin, a waste product of red blood cell breakdown.

The carriers of micro-organisms that cause diseases are called vectors. Vectors are living organisms, such as mosquitoes or ticks, that can transmit pathogens from one host to another. They act as intermediaries in spreading diseases by carrying and transmitting the infectious agents. Antibodies are molecules produced by the immune system to fight against pathogens, carriers are individuals who carry the microorganisms without showing symptoms, and germs are microorganisms that can cause diseases.

The chemical reaction between hydrogen gas and oxygen gas produces water. This is because hydrogen and oxygen react to form water molecules through a process called combustion. In this reaction, hydrogen and oxygen atoms combine to form water molecules, which are in the liquid state. Therefore, the correct answer is (c) water.

In a clinical thermometer, the mercury can be replaced by an alcohol. This is because alcohol has a lower boiling point compared to mercury, making it suitable for measuring body temperature accurately. Additionally, alcohol is less toxic and safer to use in medical instruments.

When a force moves through a distance, the result is work. Work is defined as the product of the force applied on an object and the distance through which the force is applied. It is a measure of the energy transferred to or from an object by means of a force acting on it. Therefore, work is the correct answer in this context.