Levels of Organization (anatomy): Difference between revisions
organs can also be made from structures |
|||
Line 22: | Line 22: | ||
Tissues make up structures. Some structures could make up organs |
Tissues make up structures. Some structures could make up organs |
||
Level 5 3/4 |
|||
Disregard level 5 1/2 |
|||
==Level 6: Organs== |
==Level 6: Organs== |
Revision as of 17:57, 11 September 2013
It has been suggested that this article be merged with Biological organisation. (Discuss) Proposed since November 2012. |
Level 1: Atoms
Atoms are the smallest part of the cell that is studied in biology.
Level 2: Molecules
Molecules are made of one or more atoms bonded together.
Level 3: Organelles
Organelles are composed of molecules, and carry out specific functions for each cell.
Level 4: Cells
A cell is the smallest functional unit of life. All living organisms are composed of one or more cells.
Level 5: Tissues
Tissues make up the second level of organization. They are formed by the joining of cells that have similar function or structure.
Level 5 1/2: Structures
Tissues make up structures. Some structures could make up organs
Level 5 3/4
Disregard level 5 1/2
Level 6: Organs
An organ is a group of tissues that perform a specific function or group of functions. This is the third level of organization.
Level 7: Organ Systems
An organ system is a collection of organs that perform a specific function- the circulatory system or digestive system for example. Several organ systems are present in humans, but many other types exist in different organisms. An organ system cannot live by itself and is dependent on other organ systems to form an organism. Here is a list of human organ systems and the organs they are composed of:
- Circulatory system: the heart, blood, and blood vessels
- Digestive system: the salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, rectum, and anus
- Endocrine system: the hypothalamus, pituitary gland, pineal body, thyroid, parathyroids, and adrenals
- Integumentary system: the skin, hair, and nails
- Lymphatic system: the leukocytes, tonsils, adenoids, thymus, and spleen
- Muscular system: the muscles
- Nervous system: the nerves, brain, spinal cord, and peripheral nerves
- Reproductive system: the ovaries, fallopian tubes, uterus, vagina, mammary glands, testes, vas deferens, seminal vesicles, prostate, and penis
- Respiratory system: the pharynx, larynx, trachea, bronchi, lungs, and diaphragm
- Skeletal system: the bones, cartilage, ligaments, and tendons
- Urinary system: the kidneys, ureters, bladder, and urethra
Organ systems may be closely intertwined and called things like the musculoskeletal system or neuroendocrine system.
Level 8: Organisms
An organism is a being that's able to perform simple acts of survival. We humans are one for example.
Level 9: Population
A population is a group of organisms of the same species.
Level 10: Community
A community is a group of interacting organisms of multiple species sharing a populated environment.
Level 11: Ecosystem
Ecosystems has organisms but also includes the land, water, air, rocks, and other non living things in a given area.
Level 12: Biosphere
A biome is a major regional or global community of organisms. Biomes are usually characterized by the climate in the given area.
See also
- Biological organization
- Cell Theory
- Basic functions of an organism/ organ system/ organ/ tissue/ cell
References
- Harcourt Science Textbook 2007 Edition
- Science Class
- Cells (a book)