1. Biology Unit 1 From Molecules to Organisms: Structures and Processes
K Coogler

2. Levels of Organization
Subatomic Particles – electrons, protons, and neutrons
Atom – hydrogen atom, lithium atom, etc.
Molecule – water molecule, glucose molecule, etc.
Macromolecule – protein molecule, DNA molecule, etc.
Organelle – mitochondrion, Golgi apparatus, nucleus, etc.
Cell – muscle cell, nerve cell, etc.
Tissue – epithelia, connective, muscle and nerve
Organ – skin, femur, heart, kidney, etc.
Organ System – skeletal system, digestive system, etc.
Organism – the human

3. Levels of Organization
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Subatomic particles
Atom
Organ system
Molecule
Macromolecule
Organ
Organelle
Organism
Cell
Tissue

4. Levels of Organization
Scientist organize multicellular organisms into five basic levels of organization; beginning with cells and moving to increasingly complex structures. The five levels are:
Cell – basic unit of life
Tissue – similar cells that work together to perform a specialized function
Organ – a group of tissues that carry out a specialized function of the body
Organ system – two or more organs that work together to perform body functions
Organism – together

5. Levels of Organization

6. Levels of Organization – Organ System
Organ system – two or more organs that work together to perform body functions. Organ systems interact to help the organism maintain internal stability or homeostasis.
Ex. The muscular system interacts with the circulatory system to help pump your blood and delver oxygen and nutrients to cells.

8. Levels of Organization -
Organs
An organ is a group of tissues that carry out a specialized function of the body.

9. Levels of Organization -
Tissues
Tissue – a group of similar cells that work together to perform a specialized function, usually as part of an organ. In the human body, organs are made up of four general types of tissues;

10. Levels of Organization -
Cells
Humans, like other multicellular organisms are collections of specialized cells that work together. A cell is the most basic unit of life. The cells that make up an organism arise from a single cell that goes through successive divisions to make new cells.
Cell differentiation is the process by which cells become specialized in structure and function.

11. Cell Differentiation

12. The Cell & Cell Structure
The basic level or organization in living things is the cell. Organisms may be made up of just one cell or they may be multicellular.
The structural and functional unit of every organism is one of two types of cells: prokaryotic or eukaryotic
Most prokaryotes are microscopic, single-celled organisms. Eukaryotes may be multicellular or single-celled organisms.
Organisms of the domains Bacteria and Archaea consist of prokaryotic cells
Protists, fungi, animals, and plants all consist of eukaryotic cells

13. Cell Structure: Animal vs Plant