Biology: Organ Systems and Multicellular Organisms

Study Notes

Definition: A group of organs that work together to perform a specific function
Examples:
- Circulatory system: heart, blood vessels, blood
- Nervous system: brain, spinal cord, nerves
- Digestive system: mouth, esophagus, stomach, small intestine, large intestine
Functions:
- Maintain homeostasis
- Respond to stimuli
- Support growth and development
- Regulate body functions

Animals:
- Vertebrates: have a backbone (e.g., humans, dogs, birds)
- Invertebrates: no backbone (e.g., insects, worms, jellyfish)
Plants:
- Flowering plants: produce flowers and seeds (e.g., roses, oak trees)
- Non-flowering plants: do not produce flowers or seeds (e.g., mosses, ferns)
Fungi: obtain nutrients by decomposing organic matter or forming symbiotic relationships (e.g., mushrooms, molds)

Single-celled: composed of only one cell
Self-sufficient: able to carry out all necessary life functions independently
Variety of shapes and sizes: from spherical to irregular shapes, ranging from 1-500 μm in diameter
Reproduce by: binary fission, budding, or fragmentation
Examples:
- Bacteria (e.g., E. coli)
- Protists (e.g., Amoeba, Paramecium)
- Yeast (e.g., Saccharomyces cerevisiae)

A group of organs that work together to perform a specific function
Examples of organ systems include:
- Circulatory system, consisting of heart, blood vessels, and blood
- Nervous system, comprising brain, spinal cord, and nerves
- Digestive system, consisting of mouth, esophagus, stomach, small intestine, and large intestine
Organ systems perform various functions, including:
- Maintaining homeostasis
- Responding to stimuli
- Supporting growth and development
- Regulating body functions

Classified into two groups:
- Vertebrates, characterized by the presence of a backbone (e.g., humans, dogs, birds)
- Invertebrates, lacking a backbone (e.g., insects, worms, jellyfish)

Classified into two groups:
- Flowering plants, producing flowers and seeds (e.g., roses, oak trees)
- Non-flowering plants, not producing flowers or seeds (e.g., mosses, ferns)

Obtain nutrients by:
- Decomposing organic matter
- Forming symbiotic relationships
Examples include mushrooms, molds, and other species

Single-celled, composed of only one cell
Self-sufficient, able to carry out all necessary life functions independently
Exhibiting a variety of shapes and sizes, ranging from spherical to irregular shapes and 1-500 μm in diameter
Reproducing through:
- Binary fission
- Budding
- Fragmentation
Examples include:
- Bacteria (e.g., E. coli)
- Protists (e.g., Amoeba, Paramecium)
- Yeast (e.g., Saccharomyces cerevisiae)