Organization of an Organism
An organism is anything that lives. In multi-cellular organisms, there is a hierarchy of parts for organization. From smallest to largest, it is cells, tissues, organs, organ systems, and organisms.
Plant cells feature a cell wall, which forms a rough outer membrane around the cell itself and holds the cell in its rectangular shape. Like most other cells, plant cells have nuclei, which are the central points of the cell. The nucleus is involved in initiating many of the central processes to the cell’s existence. While animal cells will have small vacuoles, the vacuole of a plant cell could become up to 90% of the area inside of the cell. Since many plant cells carry out photosynthesis and animal cells do not, chloroplasts and plastids are present in plant cells and not in animal cells.
Animal cells have a much more rounded shape than their animal counterparts due to the lack of a cell wall; they will have a cell membrane as an outer casing and may have cilia, but not the rigid inflexible end that a cell wall is. Centrioles are present in animal cells and only a small percentage of plant cells.
For single-celled organisms, all of the functions of life are carried out here, and the organism is incapable of any action or process that requires a higher level of organization.
Tissues are collections of cells of a certain type. Their presence is paramount to the existence and effectiveness of organs. Depending on the part of the body, tissue has very specific duties to run and protect the organs.
A collection of tissues all working together for the same purpose form an organ. For example, the heart performs very essential duties for the continued existence of an animal, but it can not do the job of the liver or bladder.
Collections of organs that work together to perform any function are considered organ systems. For example, the mammalian respiratory system includes the trachea, bronchi, bronchioles, lungs, and diaphragm. Each organ in the system performs its job to exchange carbon dioxide as waste outside of the body and process Oxygen which is important for the body to continue to operate.
The final level of organization of an organism is the organism itself. All other levels are nested within this one. In a single celled organism, of course, there is only the organism and its one single cell. In a single human, however, we see each level nested withing the one above it. The human is the organism. It contains a respiratory system, which is made up of several organs. These organs are each in turn made of similar types of tissues that all work together, which are in themselves collections of cells.
Organization of the Organism
1. Zoom: top left, Annie with cell phone
Hot Spot: cell-phone = cell
Learning: In this CoursePic, we'll follow Little Orphan Annie as she tries to find just the right sound to record her comeback hit, and in the process, discover the five organizational levels of organisms. Cells are the basic building blocks of all living organisms, and the first of the five organization levels of an organism. Little Orphan Annie's cell-phone represents the cell.
Story: It's been a long time since Little Orphan Annie had any success. If she wants to make a come back, she'll need a real hit! She sets out to record a song that will top the charts, but she just can't seem to get the right sound. Her cell-phone's monophonic ring tone is just too bland.
2. Zoom: top middle, Annie with tissue box
Hot Spot: cell-phone-tissue-box = cellular tissue
Learning: Tissue is a collection of cells of the same type and origin working together, and is the next organization level up from cell.
Story: In the next scene, Orphan Annie finds a tissue box full of cellphones similar to hers playing a little better sounding music. There is one stray musical notes moving to the right, she decides to follow it to see where it leads.
3. Zoom: Organ piano
Hot Spot: Organ = Organ piano
Learning: A compilation of tissues joined to form a structural unit is called an organ.
Story: The lone musical note lead Orphan Annie to a big heart made up of "tissue boxes" playing an organ that has one pipe with a red heart on top. Orphan Annie gets a little more excited and decides to follow the few notes hovering to the right again.
4. Zoom: Large Organ - organist shows the circulatory system
Hot Spot: Organ Systems = Large Organ - organist shows the circulatory system
Learning: Functionally associated organs often collaborate to form whole organ systems. The human body is composed of 11 organ systems. These include the Integumentary, Muscular, Skeletal, Nervous, Circulatory, Lymphatic, Respiratory, Endocrine, Urinary/excretory, Reproductive, and Digestive systems. The large organ here shows the cluster of organ systems, and the organist leaves his circulatory system exposed.
Story: Orphan Annie finds her sister dancing to the music of a very veiny organist playing the organ. They hold hands and joyfully listen to the music. The music is great but not perfect for Annie’s song, so she decides to follow the musical notes yet again.
5. Zoom: All the different organs on the piano pipes
Hot Spot: Organism = All the different organs on the piano pipes together
Learning: An organism is any adjoining living system consisting of one or more cells capable of reproduction, development, growth, homeostasis, and response to stimuli to some degree. Multicellular organisms are composed of trillions of cells arranged into specialized tissues and organs.
Story: Orphan Annie finally finds her music. The musical notes lead her to a bright and sunny place. There is an organist playing perfect music on an organ with several colored pipes, and on top of each pipe is a different organ of the body. Orphan Annie is very excited. She's finally found her hit tune!