Science Final Exam • Study Guide • June 2025

Vocabulary-style flashcards covering physics/measurement, chemistry basics, electricity, cell biology, reproduction, and genetics from the 2025 Science Final Exam study guide.

Pure substance

Made up of only one type of particle (atoms or molecules).

Mixture

Contains two or more different substances (elements and/or compounds) that are physically combined but not chemically bonded.

Homogeneous Mixture

Also known as a SOLUTION; it consists of TRUE PARTICLES (i.e. atoms or molecules). Example: Sugar Water.

Heterogeneous Mixture

Also known as a MECHANICAL MIXTURE; it has a non-uniform composition where different parts (phases) can be seen and no dissolving occurs because 'bits' are larger than molecules.

Solute

The substance that is DISSOLVED in another substance within a solution.

Solvent

The substance in which the SOLUTE is dissolved within a solution.

Physical change

Occurs when materials change but no new materials with no new properties are made.

Chemical change

Occurs when materials change into new materials that have new properties.

Elements

A pure substance made up of only one type of atom (e.g., Oxygen, $O$ or Sodium, $Na$).

Compounds

A pure substance made of two or more different elements that are chemically bonded together (e.g., $H_2O$).

Positively charged objects

Objects that have lost electrons.

Negatively charged objects

Objects that have gained electrons.

Ionic Bond

Formed by the transfer of electrons where one atom loses electrons and another gains them (e.g., $NaCl$).

Covalent Bond

Formed by the sharing of electrons between atoms to achieve stability (e.g., $H_2O$).

Isotope

A form of an element that has the same number of protons (same atomic number) but a different number of neutrons in its nucleus.

Reactivity Pattern (Periodic Table)

Elements are more reactive the further left or right they are (excluding group 18) and the higher up they are (lower period numbers).

Induction

Charging objects without direct contact by using the presence of a charged object to rearrange electrons in a nearby neutral object.

Conduction

Charging by direct contact; electrons are transferred from one object to another by touching.

Power ($P$)

How fast energy is changed into useful energy, measured in Watts ($W$) where $1\text{ watt} = 1\text{ joule per second}$. Formula: $P = \frac{E}{t}$.

Voltage ($V$)

Also called potential difference or electro-motive force (EMF); a measure of charge separation, measured in Volts ($V$).

Current ($I$)

The amount of charge that flows by a certain point every second when electric charges move.

Parallel circuit

A circuit connected in such a way that there are multiple paths for electricity flow.

Series circuit

A circuit connected in such a way that there is a single path for electricity flow.

Golgi body

Packages proteins.

Cell Wall

Rigid outer layer of plant cells that provides structure and support.

Lysosomes

Break down food and old cell parts.

Cell Membrane

Outer barrier that controls what comes in and out of the cell.

Cytoplasm

Jelly like fluid made of cytosol and organelles where most life processes occur.

Endoplasmic Reticulum

Passageway to bring proteins through the cell.

Mitochondria

Make energy for the cell; sometimes called the 'power house' of the cell.

Nucleus

Control center of the cell that contains DNA.

Chloroplast

Food making organelle in plant cells that contains chlorophyll for photosynthesis.

Ribosomes

Organelles that make proteins.

Vacuoles

Store food, water, and waste.

Peroxisomes

Filled with enzymes that digest toxic substances.

Cilia

Microscopic hairs extending from the cytoskeleton that allow for movement.

Flagellum

Longer tail-like extension of the cytoskeleton that allows for movement of some cells.

Centrioles

Microtubules found only in animal cells that organize the cell during cell division.

Interphase

The stage of the cell cycle where chromosomes are copied.

Prophase

Mitosis begins; centrioles appear and move to opposite ends, and spindle fibres form between poles.

Metaphase

Chromatids attach to the spindle fibres.

Anaphase

Chromatids separate and move to opposite ends of the cell.

Telophase

Two new nuclei form and mitosis ends.

Cytokinesis

The final stage of the cell cycle where the cell membrane moves inward to create two daughter cells.

Binary fission

Asexual reproduction where genetic material is duplicated and the cell splits into two identical daughter cells.

Meiosis

Cell division in sexually reproducing organisms that reduces the number of chromosomes in gametes.

Mitosis

Cell division that produces identical cells by dividing the nucleus.

External Fertilization Requirement

Requires a wet environment.

Progesterone

The hormone that indicates pregnancy; made by ovaries to maintain the uterus lining.

Alleles

Different forms of a gene (e.g., Eye colour).

Homozygous

When the alleles for a trait are both the same (e.g., $AA$ or $aa$).

Heterozygous

When the alleles for a trait are both different (e.g., $Aa$).

Hybrid

An organism produced by crossing parents with different traits; possesses a heterozygous genotype (e.g., $Tt$).

Genotype ratio

The number of a particular allele combination (genetic makeup) in a Punnett square cross.

Phenotype ratio

The number of offspring that show a particular physical appearance or trait in a Punnett square cross.

Incomplete dominance

When a blending of traits occurs because one allele is not completely dominant over the other (e.g., Red and White making Pink).

Testosterone

Male hormone made by the testes that controls sperm production and develops male body features.

Estrogen

Female hormone made by the ovaries that builds up the lining of the uterus and helps develop female body features.

FSH (Follicle-Stimulating Hormone)

Hormone made by the brain (Pituitary Gland) that helps eggs mature or aids in sperm production.

LH (Luteinizing Hormone)

Hormone made by the brain (Pituitary Gland) that triggers ovulation or tells testes to release testosterone.