Comprehensive JHS Science Review

These vocabulary flashcards cover standard Junior High School science topics including biology, chemistry, physics, and environmental studies as outlined in the NaCCA curriculum notes.

Animal Nutrition

The study of how animals obtain food, digest it, absorb nutrients, and use them for energy, growth, repair, reproduction, and production of meat, eggs, milk, wool, or labour.

Ruminants

Animals with a four-part stomach (rumen, reticulum, omasum, and abomasum) that chew cud, such as cattle, goats, and sheep.

Balanced ration

Feed that contains all the nutrients an animal needs (carbohydrates, proteins, fats, vitamins, minerals, and water) in the right amounts.

Respiration

The chemical process by which living cells release energy from food, expressed as: $\text{Glucose} + \text{Oxygen} \rightarrow \text{Carbon dioxide} + \text{Water} + \text{Energy}$.

Aerobic respiration

A form of respiration that occurs in the presence of oxygen, releasing a large amount of energy.

Anaerobic respiration

Respiration that occurs without enough oxygen; in humans, it produces lactic acid, while in yeast, it produces alcohol and carbon dioxide.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs between the air and the blood capillaries.

Electricity

A form of energy produced by the presence or movement of electric charges.

Static electricity

Electricity at rest that occurs when charges build up on a surface, such as rubbing a plastic comb through dry hair.

Ohm’s Law

A law stating that voltage equals current multiplied by resistance, represented by the formula $V = I \times R$.

Acid

A substance that produces hydrogen ions when dissolved in water, tastes sour, and turns blue litmus paper red.

Alkali

A base that dissolves in water; examples include sodium hydroxide and ammonia solution.

Neutralisation

The chemical reaction between an acid and a base to form salt and water, represented as: $\text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water}$.

Communicable diseases

Diseases that can spread from one person to another, such as cholera, malaria, measles, and COVID-19.

Deficiency diseases

Diseases caused by a lack of specific nutrients in the diet, such as kwashiorkor (lack of protein) or anaemia (lack of iron).

Mixture

A substance formed when two or more substances are physically combined without chemical bonding, where each substance keeps its individual properties.

Homogeneous mixture

A mixture that is uniform throughout, such as a salt solution, vinegar, or air.

Heterogeneous mixture

A mixture that is not uniform throughout, such as oil and water or sand and water.

Friction

A force that opposes motion between two surfaces in contact and acts in the opposite direction to movement.

Mixed farming

A farming system where the farmer keeps animals and grows crops on the same farm simultaneously.

Sustainable farming

Farming in a way that meets present needs for food and income without destroying the land for future generations.

Mutualism

A biotic relationship in which both organisms benefit, such as bees and flowers or nitrogen-fixing bacteria and leguminous plants.

Matter

Anything that has mass and occupies space, existing in three states: solid, liquid, and gas.

Element

A pure substance made of only one kind of atom, such as oxygen, carbon, or iron.

Micronutrients

Essential plant nutrients needed in small amounts, including iron, zinc, copper, manganese, boron, molybdenum, and chlorine.

Arteries

Blood vessels that carry blood away from the heart to other parts of the body.

Machine

A device that makes work easier by changing the direction of force, reducing effort, or increasing speed or distance.

Mechanical advantage

A measure of how much a machine multiplies effort, calculated as $\text{Mechanical Advantage} = \text{Load} \text{ / } \text{Effort}$.

Atom

The smallest particle of an element that can take part in a chemical reaction, composed of protons, neutrons, and electrons.

Atomic number

The number of protons in the nucleus of an atom, which also equals the number of electrons in a neutral atom.

Mass number

The total number of protons and neutrons in the nucleus of an atom.

Conduction

The transfer of heat through a solid material from particle to particle, occurring most efficiently in metals.

Convection

The transfer of heat through liquids and gases by the movement of heated particles, forming convection currents.

Radiation

The transfer of heat through electromagnetic waves without the need for a physical medium, such as heat from the sun.

Environment

Everything around us, including living (biotic) factors like plants and animals, and non-living (abiotic) factors like air, water, and soil.

Green economy

An economy that aims to improve human wellbeing and social equity while significantly reducing environmental risks and ecological scarcities.