Year 9 Science: Biology & Chemistry Exam Revision 2026

Comprehensive vocabulary flashcards covering Year 9 Biology (Reproduction, Nervous/Endocrine Systems, Diseases) and Chemistry (Atoms, Periodic Table, Chemical Reactions) based on the 2026 Semester 1 Exam Revision Pack.

Asexual reproduction

A type of reproduction where living things reproduce without a partner, helping their species survive by producing offspring from a single parent.

Sexual reproduction

A type of reproduction involving two parents that results in genetically different offspring.

Binary fission

A form of asexual reproduction typically found in prokaryotes where a cell divides into two identical parts.

Budding

A form of asexual reproduction where a new organism develops from an outgrowth or bud due to cell division at one particular site.

Pollination

The process of transferring pollen from the anther of a flower to the stigma.

Fertilisation

The fusion of male and female gametes, such as sperm and ovum, to form a zygote.

Homeostasis

The body’s ability to maintain stable internal conditions despite changes in the external environment.

Negative feedback

A process that helps keep the body’s internal environment stable by responding to changes and returning conditions to a set point.

Sensory neuron

A type of neuron that carries nerve impulses from sensory receptors to the central nervous system.

Motor neuron

A type of neuron that carries signals from the central nervous system to effectors like muscles to initiate a response.

Hormone

Chemical messengers produced by the endocrine system that help the body sense and respond to changes.

Glucagon

A hormone produced by an organ in the body to help regulate internal balance, specifically related to glucose levels.

Infectious disease

A disease that is caused by pathogens and can be spread between people.

Non-infectious disease

A disease that cannot be spread between people and is often caused by genetics or lifestyle choices.

Pathogen

A microbe or agent, such as bacteria, viruses, or fungi, that causes disease.

Vaccine

A substance used to stimulate the body's immune system to provide immunity against specific infectious diseases.

Atomic number

A value equal to the number of protons in the nucleus of an atom, which determines the element's identity.

Mass number

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

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons.

Alpha particle

A type of radioactive particle emitted during decay; it has the least penetrating power and can be stopped by materials like paper.

Beta particle

A type of radioactive particle emitted during decay with moderate penetrating power.

Gamma ray

A high-energy electromagnetic radiation emitted during radioactive decay with the greatest penetrating power.

Law of Conservation of Mass

A scientific law stating that during a chemical reaction, atoms are rearranged but not created or destroyed, meaning total mass remains constant.

Exothermic reaction

A chemical reaction that releases heat to its surroundings, often resulting in a temperature increase.

Endothermic reaction

A chemical reaction that absorbs heat from its surroundings, often resulting in a temperature decrease.

Synthesis reaction

A type of chemical reaction where two or more substances combine to form a single new substance.

Decomposition reaction

A chemical reaction where a single substance breaks down into two or more simpler substances.

Displacement reaction

A chemical reaction in which one element replaces another element in a compound.

Catalyst

A substance that increases the rate of a chemical reaction without being consumed in the process.

Reactant

A starting substance in a chemical reaction that undergoes change to form products.

Product

A substance that is formed as the result of a chemical reaction.