Ch. 1 An Introduction to Biology

Science: The systematic study of the natural world through observation and experimentation, aiming to understand how things work.

Biology: The branch of science that studies living organisms, their structure, function, growth, evolution, and interactions with their environment.

Atom: The smallest unit of matter that retains the properties of an element, consisting of a nucleus (protons and neutrons) and electrons surrounding it.

Molecule: Two or more atoms bonded together, forming the smallest unit of a chemical compound that can participate in chemical reactions.

Cell: The basic structural and functional unit of all living organisms. Cells are the building blocks of life.

Tissue: A group of similar cells that work together to perform a specific function in the body.

Organ: A structure made up of different types of tissues working together to perform specific tasks (e.g., the heart, lungs, or brain).

Organ System: A group of organs that work together to perform a larger function for the body (e.g., the circulatory system, digestive system).

Organism: An individual living thing, which can be a single cell (like bacteria) or multicellular (like animals, plants).

Population: A group of individuals of the same species living in the same area at the same time, capable of interbreeding.

Community: All the populations of different species that live and interact in the same area.

Ecosystem: A community of living organisms interacting with their physical environment (air, water, soil), including both biotic (living) and abiotic (non-living) components.

Biosphere: The sum of all ecosystems on Earth, encompassing all living organisms and their environments.

Matter: Anything that has mass and takes up space. It is made up of atoms and molecules.

Energy: The ability to do work or cause change. In biological systems, energy is essential for processes like growth, movement, and reproduction.

Hypothesis: A testable and falsifiable explanation for an observation or phenomenon, often forming the basis for experimentation.

Theory: A well-substantiated explanation of an aspect of the natural world that is based on a body of evidence and can be used to predict outcomes.

Law: A statement that describes a consistent and universal relationship observed in nature, often expressed mathematically (e.g., Newton's laws of motion).