Combined Science Form 2 Vocabulary Review

Comprehensive vocabulary flashcards covering the FORM 2 Combined Science curriculum including Biology, Chemistry, and Physics topics from the 'Step Ahead' Learner's Book.

Organisms

Living things that display basic activities known as life processes, including nutrition, respiration, excretion, homeostasis, response to environment, reproduction, and growth.

Homeostasis

The process by which living organisms control their internal conditions to maintain a state of balance.

Carolus Linnaeus

A Swedish doctor and botanist known as the pioneer in classifying organisms and developing the binomial system for scientific nomenclature.

Kingdom Monera

A classification kingdom consisting of single-celled organisms that have no nucleus, such as bacteria and blue-green algae.

Species

The smallest unit of classification, defined as a group of organisms that have many features in common and can freely interbreed to produce fertile offspring.

Binomial system

A two-part scientific naming system where the genus name appears first (capitalized) and the species name last, typically written in italics.

Phenotype

The observable characteristics of individuals in a species or population.

Continuous variation

Variation where values change gradually over a range, such as height, weight, or leaf length.

Discontinuous variation

Variation where there are only a limited number of possibilities for a phenotype, such as blood groups, gender, or tongue rolling.

Genotype

The internal genetic make-up of an individual organism.

Mutation

The change of genetic material during fertilization and cell division that can introduce new heritable traits into a species.

Natural selection

The mechanism for evolutionary change where individuals with variations best suited to their environment survive longer and reproduce more successfully.

Artificial selection

The process where humans choose to interbreed animals or plants with specific traits to suit human needs.

Photosynthesis

The process by which green plants convert light energy into chemical energy contained in glucose, represented by the word equation: $\text{carbon dioxide} + \text{water} \frac{\text{light energy}}{\text{chlorophyll}} \text{glucose} + \text{oxygen}$.

Autotrophs

Organisms, such as green plants, that are 'self-feeders' and make their own organic matter from inorganic nutrients.

Heterotrophs

Organisms, such as humans and animals, that are 'other-feeders' and must feed on other organisms for energy.

Chloroplasts

Organelles inside mesophyll cells that contain green chlorophyll pigment to absorb light energy for photosynthesis.

Stomata

Small openings in the leaf epidermis that allow gases like carbon dioxide and oxygen to diffuse in and out.

Herbivores

Consumers that feed only on plants, including grazers that eat grass and browsers that eat tree leaves.

Decomposers

Feeders such as bacteria and fungi that get nutrients by absorbing them from dead organic matter, releasing inorganic substances back into the feeding cycle.

Ingestion

The first stage of nutrition where food is put into the mouth and enters the alimentary canal.

Peristalsis

The wave-like movement of muscles contracting and relaxing along the esophagus to move food to the stomach.

Chyme

A mixture of food and gastric juice created by the mechanical and chemical processing in the stomach.

Villi

Finger-like structures on the lining of the small intestine that increase surface area for the absorption of nutrients into the bloodstream.

Cellular respiration

The process of setting energy free from nutrients in the body's cells, following the equation: $\text{glucose} + \text{oxygen} \rightarrow \text{carbon dioxide} + \text{water} + \text{energy}$.

Alveoli

Tiny air sacs at the end of bronchioli in the lungs where gaseous exchange takes place between air and blood capillaries.

Diaphragm

The muscle sheet at the base of the chest cavity used for breathing; it contracts and moves down during inhalation.

Diffusion

The net movement of molecules from a region of higher concentration to a region of lower concentration down a concentration gradient.

Osmosis

The movement of water molecules across a selectively permeable membrane from a place of higher water concentration to a place of lower water concentration.

Active transport

The transport of molecules or ions against their concentration gradient across a membrane, requiring extra energy and transport proteins.

Xylem

Vascular tissue in plants made of vessels and tracheids that transports water and dissolved minerals from the roots to the leaves.

Phloem

Vascular tissue in plants, consisting of sieve tubes and companion cells, that carries food made in the leaves to other parts of the plant.

Translocation

The process of transporting manufactured carbohydrates through the phloem tissue.

Haemoglobin

The red iron-containing pigment in red blood cells that facilitates the transport of oxygen and carbon dioxide.

Double fertilisation

A process in flowering plants where one male gamete fertilises the egg cell to form an embryo, and the other fuses with cells to develop into endosperm.

Testosterone

The main male sex hormone produced in the testes that develops and maintains male secondary sex characteristics.

Placenta

An organ formed during pregnancy that allows for the exchange of nutrients, waste, and gases between the mother and the embryo.

Amnion

The inner membrane filled with amniotic fluid that cushions and protects the embryo during pregnancy.

Pathogen

A disease-causing agent such as a virus, bacteria, fungus, or parasite.

Schistosomiasis

Also known as bilharzia or snail fever, a parasitic disease caused by Schistosoma flatworms that use freshwater snails as secondary hosts.

Flocculant

A chemical added during water treatment to speed up the settling of clumps of solid particles at the bottom of sedimentation tanks.

Colorimetry

A method of measuring the concentration of colored substances using a device that measures light absorption at specific wavelengths.

Mole

The chemist's unit describing a quantity of particles, where one mole equals Avogadro's constant ($6.023 \times 10^{23}$ particles).

Neutralisation

The reaction between an acid and a base to produce a salt and water, resulting in a neutral pH of $7$.

Saponification

The chemical process of combining a fat and an alkali to form soap and glycerol.

Physical change

A reversible process where no new substance is formed and properties of substances do not change, such as melting or evaporation.

Chemical change

An irreversible process that produces a new substance with different properties, such as rusting, burning, or ripening.

Oxidation

A chemical reaction in which a substance gains oxygen.

Reduction

A chemical reaction in which a substance loses oxygen.

Complete combustion

Occurs when a fuel burns in plenty of oxygen to produce carbon dioxide, water, and energy.

Incomplete combustion

Occurs when a fuel burns in insufficient oxygen, producing carbon monoxide, soot, water, and less energy.

Global warming

The gradual heating of the Earth caused by elevated levels of waste gases like carbon dioxide in the atmosphere.

Newton (N)

The unit used to measure the magnitude of a force.

Resultant force

A single force that has the same effect as two or more forces acting together on an object.

Moment of force

The turning effect of a force around a pivot, calculated as $\text{Force} \times \text{Perpendicular distance}$.

Friction

A force between two surfaces in contact that opposes motion.

Levers

Simple machines consisting of a stiff bar and a fixed turning point called a fulcrum or pivot.

Potential energy

Energy stored in an object because of its position, such as gravitational potential energy ($\text{GPE} = \text{weight} \times \text{height}$).

Kinetic energy

The energy of an object produced by its movement.

Umbra

A complete shadow formed when light is totally blocked by an object.

Penumbra

A partial shadow surrounding the umbra where light is only partially blocked.