Year 10 End of Year Exam Revision: Biology, Physics, and Chemistry

Comprehensive vocabulary flashcards covering Year 10 End of Year Exam Revision across Biology, Physics, and Chemistry.

DNA

The molecule located in the nucleus that stores genetic information, structured as a double helix composed of bases Adenine (A), Thymine (T), Cytosine (C), and Guanine (G), where A pairs with T and C pairs with G.

Gene

A segment of DNA that codes for a particular protein and serves as the fundamental unit of heredity.

Chromosomes

Structures carrying genes; humans have $46$ chromosomes in body cells (diploid) and $23$ in gametes (haploid). Sex chromosomes determine gender ($XX$ in females, $XY$ in males).

Mutations

Changes in DNA sequence that can lead to dominant or recessive traits, contributing to genetic variability.

Mitosis

A form of cell division that produces two identical diploid body cells; responsible for growth, repair, and maintenance.

Meiosis

A form of cell division that produces haploid gametes (sperm and eggs), introducing genetic variation through recombination and segregation.

Gametes

Reproductive cells; male gametes (sperm) are produced in the testes and female gametes (eggs/ovum) are produced in the ovaries.

Fertilisation

The process that typically occurs in the fallopian tubes where gametes unite to form a zygote, which subsequently develops in the uterus.

Reproductive Hormones

Hormones that regulate puberty and reproductive function, primarily testosterone in males and oestrogen in females.

Darwin's Theory of Natural Selection

A theory explaining adaptation and evolution based on variation, competition, and selection pressures that favour beneficial traits.

Scientific Laws vs. Theories

Scientific laws describe consistent observations, while theories explain underlying mechanisms (such as evolutionary theory).

Evidence for Evolution

Four key lines of evidence: fossil records, comparative anatomy, molecular biology, and embryology.

Microevolution

Small-scale evolutionary changes occurring within a species.

Macroevolution

Larger evolutionary changes that can produce new species.

Biotechnology

The manipulation of genetic material for applications in medicine, agriculture, and industry, involving ethical considerations regarding health, environment, consent, and social consequences.

Scalar Quantities

Physical quantities that possess magnitude only, such as distance, time, and speed.

Vector Quantities

Physical quantities that possess both magnitude and direction, such as displacement, velocity, force, and acceleration.

Speed

A scalar quantity with no direction, calculated as $\text{Speed} = \frac{\text{Distance}}{\text{Time}}$.

Velocity

A vector quantity that includes direction, calculated as $\text{Velocity} = \frac{\text{Displacement}}{\text{Time}}$.

Acceleration

The rate of change of velocity over time, calculated as $a = \frac{v - u}{t}$; it can involve a change in speed, a change in direction, or both.

Deceleration

Negative acceleration, indicating a reduction in velocity.

Newton's First Law of Motion

Every body remains in a state of rest or uniform motion unless acted upon by a net external force.

Newton's Second Law of Motion

The amount of acceleration of a body is proportional to the acting force and inversely proportional to the mass of the body ($F = m \times a$).

Newton's Third Law of Motion

For every action there is an equal but opposite reaction; if object A exerts a force on object B, then object B will exert an equal but opposite force on object A.

Distance-Time Graph Gradient

Represents speed: a steeper gradient indicates a faster speed, a flat horizontal line indicates the object is stopped, and a negative gradient indicates returning to the start.

Velocity-Time Graph Gradient

Represents acceleration: a positive gradient means accelerating, a flat horizontal line indicates constant speed, and a negative gradient indicates deceleration.

Area Under a Velocity-Time Graph

Represents the total distance travelled by the object.

Atom

The smallest unit of matter, which makes up all matter.

Element

A pure substance that contains only one kind of atom (e.g., Helium, $O_2$).

Compound

A substance that contains two or more kinds of atoms chemically bonded (e.g., Water, $H_2O$).

Subatomic Particles

The constituent particles of an atom: protons (positive charge in the nucleus), neutrons (neutral charge in the nucleus), and electrons (negative charge in electron shells).

Acid

A substance that tastes sour, is corrosive, and has a low pH between $0$ and $6$.

Base

A substance that tastes bitter, feels slippery, and has a high pH between $8$ and $14$.

Neutral Substance

A substance with a pH value of exactly $7$.

Acid-Base Neutralisation

A chemical reaction following the general equation: $\text{Acid} + \text{Base} \rightarrow \text{Salt} + \text{Water}$.

Acid-Metal Reaction

A chemical reaction following the general equation: $\text{Acid} + \text{Metal} \rightarrow \text{Salt} + \text{Hydrogen gas}$.

Acid-Metal Carbonate Reaction

A chemical reaction following the general equation: $\text{Acid} + \text{Metal Carbonate} \rightarrow \text{Salt} + \text{Water} + \text{Carbon dioxide}$.

Reaction Rate

How quickly reactants convert to products; increased by adding a catalyst, increasing temperature, increasing reactant concentration, or increasing surface area.

Catalyst

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

Combustion

A chemical reaction that requires oxygen and produces heat.

Respiration

A chemical process that converts sugar into usable energy, releasing energy more slowly than combustion.

Photosynthesis

A chemical process in which plants produce glucose and oxygen.

Precipitation Reaction

A type of chemical reaction that forms an insoluble solid product.

Alloy

A mixture of metals (or metal with other elements) designed to improve properties such as strength, durability, and corrosion resistance.

Steel

An alloy formed by combining iron and carbon.

Brass

An alloy formed by combining copper and zinc.

Bronze

An alloy formed by combining copper and tin.