JSS3 Basic Science Second Term Examination (Mock)
Family Health: Nutrition
<h1><strong>FAMILY HEALTH - NUTRITION </strong></h1> CONTENT <ol> <li>The Meaning of Nutrition</li> <li>Meaning of Food</li> <li>Classes of Food</li> <li>Balanced Diet</li> </ol> <h2><strong>The Meaning of Nutrition</strong></h2> Nutrition is the act of obtaining food by living things. It is one of the characteristics of living things. <h2><strong>Meaning of Food</strong></h2> What is food? Food is any substance that is taken to nourish the body and to meet physiological needs for growth, energy and to maintain all processes. <h2><strong>Classes of Food</strong></h2> The food we eat can be grouped into following classes based on the nutrient derived from it. Nutrient is a group of chemical compounds found in food. There are six classes of food, namely carbohydrates, proteins, fat and oil, minerals salt, vitamins and water. <img class="aligncenter wp-image-19608 size-full" src="https://classhall.com/wp-content/uploads/2018/06/classes-of-food.jpg" alt="Nutrition - classes of food" width="346" height="268" /> <h3><strong>Carbohydrates</strong></h3> These are energy giving foods e.g rice, yam, maize, cassava, wheat, bread, potato, etc. Excess intake of carbohydrate foods can lead to diseases such as diabetes, beriberi etc.
Calculation of Gravitational Force
<h1><strong>CALCULATION OF GRAVITATIONAL FORCE</strong></h1> CONTENT <ol> <li>Definition of Gravitational Force</li> <li>Calculation of Gravitational Forces</li> </ol> <h2><strong>Definition of Gravitational Force</strong></h2> This is the force with which the earth pulls all objects towards its centre. It is also called force of gravity. The instrument used for measuring gravitational force is called spring balance. <h2><strong>Calculation of Gravitational Forces</strong></h2> The unit of force is Newton (the symbol is N). The unit was named after Sir Isaac Newton who first discovered the facts about gravity. The weight of a body is the force the earth exerts on it. <strong>All forces are measured in Newton.</strong> On the earth surface the universal value of acceleration due to gravity (g) is 9.8m/s<sup>2</sup> or 10m/s<sup>2</sup> To calculate gravitational force (Gf). The following formulae are used: 1. F = mg, used for calculation of gravitational force. <strong>Example 1:</strong> Calculate the gravitational force required to pull down a mango fruit of 10kg falling with acceleration of 5m/s<sup>2</sup>. <strong>Solution:</strong> F = mg, where F is unknown, m = 10kg, a = 5m/s<sup>2</sup> ∴ F = 10 × 5 = 50 N. <strong>Example 2:</strong>
Work, Energy and Power: Potential and Kinetic Energy
<h1>WORK, ENERGY AND POWER</h1> CONTENT <ol> <li>Meaning of Work, Energy and Power</li> <li>Meaning of Potential and Kinetic Energy</li> </ol> <h2>Meaning of Work</h2> Work is said to be done whenever a force or load moves through a distance. i.e. work = force × distance moved in the direction of the force (f × d). <img class="size-full wp-image-11900 aligncenter" src="https://classhall.com/wp-content/uploads/2017/04/work-done-1.jpg" alt="Work done" width="386" height="220" /> Mathematically W(d) = f × d The unit of work is joules with symbol J. <h2>Force</h2> Force is that which changes a body’s state of rest or uniform motion in a straight line. It can as well be expressed as: Force = mass × acceleration i.e. F = m × a Where: F = force, M = mass and A = acceleration The unit of force is Newton (N). If force = mass × acceleration Work can be given as: Work = Mass × acceleration × distance. Also, W = F × S Where, W = Work done is measured in <strong>Joules (J)</strong>
Bush Burning and Deforestation
Adaptation of Organisms to their Habitats
<h1><strong>ADAPTATION OF ORGANISMS TO THEIR HABITATS</strong></h1> CONTENT <ol> <li>Meaning of Adaptation</li> <li>Characteristics of Organisms Found on Land</li> <li>Characteristics of Organisms Found in Water</li> </ol> <h2><strong>Meaning of Adaptation</strong></h2> Adaptation means special features that help an organism to live and survive in a particular habitat. Every living thing on earth belongs to one habitat or the other because it is always interacting with some biotic and abiotic components such as energy, water, air (oxygen), food, carbon dioxide and suitable living conditions. For example, there are certain species of plants and animals that can survive only in rain forest habitat and not in the desert and vice versa. <br> <h2><strong>Characteristics of Organisms Found on Land</strong></h2> The following are the characteristics of organisms found on land:
Family Health: Drug
<h1><strong>FAMILY HEALTH - DRUG</strong></h1> CONTENT <ol> <li>The Meaning of Drug</li> <li>Types of Drugs</li> <li>Sources of Drugs</li> <li>Uses of Drugs</li> <li>Side Effects of Drugs</li> </ol> <h2><strong>The Meaning of Drug</strong></h2> Drug can be defined as any substance that can affect the body positively or negatively. Drugs can be taken into the body system directly or indirectly through swallowing, injection or inhalation. Examples of drugs: Chloroquine, Phensic, Panadol, Kola nut, Alcohol, Indian hemp etc. <h2><strong>Types of Drugs</strong></h2> There are two types of drugs, namely:
Friction: Balanced and Unbalanced Forces
<h1><strong>FRICTION: BALANCED AND UNBALANCED FORCES </strong></h1> CONTENT <ol> <li>Meaning of Friction</li> <li>Uses and Advantages of Friction</li> <li>Disadvantages of Friction</li> <li>How to Reduce Friction</li> <li>How to Reduce Friction</li> <li>Balanced and Unbalanced Forces</li> </ol> <h2><strong>Meaning of Friction</strong></h2> The force that tries to stop a body from moving is called friction. Friction also means force that opposes motion. Friction can be reduced by lubrication i.e. adding oil and grease placed between the two surfaces in contact. The oil and grease are called lubricants. <h2 style="text-align: center;"><img class="size-full wp-image-36570 aligncenter" src="https://classhall.com/wp-content/uploads/2018/06/protection-from-friction.jpg" alt="Friction; Balanced and Unbalanced Forces - Protection from friction" width="396" height="239" /><strong>Protection from Friction</strong></h2> <span style="color: #008000;">Friction is a force that occurs when one object moves against another. The ceramic tiles on the outside of the space shuttle protect it from the great friction caused when the shuttle re-enters Earth’s atmosphere.</span> <h2><strong>Uses and Advantages of Friction</strong></h2> The following are the uses and advantages of friction:
Work, Energy and Power: Calculations Involving Work Done
Desertification or Desert Encroachment