Biology Basics: Atom to Organ

Atomic Structure

• The basic units of life are composed of CHNOPS: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

Molecular Structure

• A molecule is a group of atoms bonded together, examples include H2O and proteins.

Cellular Structure

• An organelle is a structure within a cell that has a specific job, similar to organs in the human body, examples include the nucleus and mitochondria.
• A cell is the smallest unit of life that can live on its own, and it makes up all living organisms.

Tissue Structure

• A tissue is a group of cells that function together, examples include skin and nervous tissue.

Organ Structure

• An organ is a collection of tissues that work together, examples include the heart and lungs.

Organ System Structure

• An organ system is a group of organs that work together to perform a specific function, examples include the respiratory, digestive, and reproductive systems.

Cellular Classification

• Cells can be classified as Prokaryotic (without a nucleus) or Eukaryotic (with a nucleus).
• Organisms are individual life forms made up of cells.

Atomic Structure

• The basic units of life are composed of CHNOPS: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.

Molecular Structure

• A molecule is a group of atoms bonded together, examples include H2O and proteins.

Cellular Structure

• An organelle is a structure within a cell that has a specific job, similar to organs in the human body, examples include the nucleus and mitochondria.
• A cell is the smallest unit of life that can live on its own, and it makes up all living organisms.

Tissue Structure

• A tissue is a group of cells that function together, examples include skin and nervous tissue.

Organ Structure

• An organ is a collection of tissues that work together, examples include the heart and lungs.

Organ System Structure

• An organ system is a group of organs that work together to perform a specific function, examples include the respiratory, digestive, and reproductive systems.

Cellular Classification

• Cells can be classified as Prokaryotic (without a nucleus) or Eukaryotic (with a nucleus).
• Organisms are individual life forms made up of cells.

Learn the fundamental concepts of biology, from the basic building blocks of life to the organization of cells, tissues, and organs. Test your understanding of atoms, molecules, organelles, cells, tissues, and organs.