The five levels of organization in a multicellular organism are cells, tissues, organs, organ systems and organisms. The level of complexity and functionality increases going from cells to organisms.Continue Reading
Cells are the basic unit of a multicellular organism. Humans have many types of cells, including blood cells, nerve cells and bone cells. Cells with similar structure and function merge to form tissues such as epithelial or connective tissue.
Organs, such as the heart or kidney, are composed of different types of tissue to perform a specific function. Organs come together to constitute organ systems such as the nervous system, digestive system and immune system. Together, these organ systems make up an organism.Learn more about Cells
Tissue and organ systems are different hierarchical levels of biological organization. Dr. Ingrid Lobo explains for Nature Education that biological organisms are systems of complexity. The basic functional unit of life is a single cell, and cells similar in function assemble to form tissue. An organ is a collection of different tissues joined as a functional unit; a group of organs working together to perform a specific task is an organ system.Full Answer >
All organisms are made up of cells, have different levels of organization, use energy, respond to and adapt to their environments, grow and reproduce. If something does not exhibit each of these characteristics, it is technically not living.Full Answer >
Mesoderm, ectoderm and endoderm tissues in animal embryos grow into every organ the animal needs at birth, according to The Embryo Project Encyclopedia at Arizona State University. Collectively, scientists refer to these three layers of tissue as germ layers, and they form early in an embryo's life through a process called gastrulation.Full Answer >
Unicellular organisms have a variety of functions depending upon the type of organism, but they generally need to synthesize all of the nutrients necessary for the cell to survive. The organism must carry out all of the life processes for the cell to function and reproduce itself, which sometimes occurs as frequently as every hour.Full Answer >