Biology Exam Review for Fall 2025

Flashcards covering key concepts from biology topics relevant for the Fall 2025 exam.

What is matter and give an example?

Matter is anything that has mass and occupies space; for example, water.

What are the parts of an atom?

An atom consists of protons, neutrons, and electrons.

How is an element identified?

An element is identified by its atomic number, which is the number of protons in its nucleus.

What is the difference between an element, isotope, and ion?

An element is a pure substance made of one type of atom, an isotope is a variation of an element with a different number of neutrons, and an ion is an atom that has gained or lost electrons.

What are the six most common elements found in living organisms?

Carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur.

What is a chemical bond?

A chemical bond is the force that holds atoms together in a molecule.

Define polar and non-polar bonds.

Polar bonds have unequal sharing of electrons, while non-polar bonds have equal sharing.

What defines a molecule?

A molecule is formed when two or more atoms are chemically bonded together.

What is the chemical structure of water?

Water has a bent shape with two hydrogen atoms covalently bonded to one oxygen atom.

What is pH?

pH is a measure of the acidity or basicity of a solution.

What are the parts of a solution?

A solution consists of a solute (the substance dissolved) and a solvent (the substance that does the dissolving, usually water).