Levels of Organization
• Identify cells, tissues, organs, organ systems,
organisms, populations, communities, and
ecosystems as levels of organization in the
biosphere.
• Identify the levels of organization in the
biosphere including cells, tissues, organs, and
organ systems,
• as well as organisms, populations, communities,
and ecosystems.
Levels of Organization
• Cell—Basic unit of structure and function in organisms.
– Some organisms, like bacteria and protists, are unicellular
(made entirely of one cell).
– Some organisms, like fungi, plants, and animals, are
multicellular (made of many cells).
– Bacteria have prokaryotic cells.
– Protists, Fungi, Plants, and Animals have eukaryotic cells.
– In multicellular organisms, cells exhibit cell specialization. They
take on specific jobs and look different from each other.
– The cells also exhibit division of labor. They split up the work of
the organism.
Levels of Organization
• Tissues—Groups of similar cells that
work together to perform a specific
function.
– 3 major tissue types in plants
• Transport tissue
• Protective tissue
• Ground tissue
– 4 major tissue types in animals
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Epithelial tissue (Protective)
Connective tissue
Muscle tissue
Nervous tissue
Levels of Organization
• Organs—structures made of different types of tissues
that work together to perform a specific function.
– Examples
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Heart
Bone
Lungs
Stomach
Small intestine
Liver
Large Intestine
Gall Bladder
Plant Roots
Plant Stems
Plant Leaves
Levels of Organization
• Organ Systems—Groups of organs that work
together to perform a specific function.
– Examples:
• Digestive system
• Circulatory system
• Excretory system
• Respiratory system
• Nervous system
• Muscular system
• Skeletal system
• Integumentary system (skin)
• Endocrine system
• Immune system
• Reproductive system
• Vascular system in plants
Levels of Organization
• Organism—A complete, individual living
thing.
• Examples:
– A single person
– A single plant
– A single bacterium
– A single protist
Levels of Organization
• Population—Groups of organisms of the
same species (kind) that live together in a
particular area at a particular time.
– Examples: All the mice in Buckhorn
– All the people in New Market
– All the earthworms in your flower bed.
– All the roses in a rose garden.
– All the mushrooms (of a particular kind) in a
meadow.
Levels of Organization
• Community—All of the populations of
organisms that inhabit the same area at
the same time.
– Examples:
• All of the species of grasses, insects, shrubs,
mice, and bacteria that live in a particular field.
Levels of Organization
• Ecosystem—All of the communities of
organisms that inhabit an area as well as
all of the nonliving components of the area
that the organisms interact with.
(Communities + Environment).
– Examples:
• All of the trees, plants, and animals in a forest plus
all of the water, rocks, air, wind, etc…
Levels of Organization
• Biosphere—The region of Earth that
supports all life. All of the environments
and organisms on Earth.
Questions
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Questions
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