Biology: Organisms and Characteristics

Study Notes

An organism is a living being that consists of one or more cells, has basic needs, and is capable of growth, reproduction, response to stimuli, and maintenance of homeostasis.
Organisms can be single-celled (unicellular) or multi-celled (multicellular).

Prokaryotes: Single-celled organisms without a true nucleus, such as bacteria.
Eukaryotes: Organisms with cells that have a true nucleus, including plants, animals, fungi, and protists.

Domain: The highest taxonomic rank, which includes Archaea, Bacteria, and Eukarya.
Kingdom: A level below the domain, which includes Monera, Protista, Fungi, Plantae, and Animalia.
Phylum (or Division in plant taxonomy): A level below the kingdom, which groups organisms based on body structure.
Class: A level below the phylum, which groups organisms based on shared characteristics.
Order: A level below the class, which groups organisms based on evolutionary relationships.
Family: A level below the order, which groups organisms based on shared characteristics.
Genus: A level below the family, which groups organisms based on close evolutionary relationships.
Species: The most specific level, which groups organisms that can interbreed and produce fertile offspring.

Cell: The basic structural and functional unit of life.
Tissue: A group of similar cells performing a specific function.
Organ: A structure composed of two or more types of tissues performing a specific function.
Organ System: A group of organs working together to perform a specific function.
Organism: A living being composed of one or more cells.

Symbiosis: A close and often long-term relationship between different species, including mutualism, commensalism, and parasitism.
Predation: A relationship in which one organism captures and consumes another.
Competition: A relationship in which organisms compete for the same resource.
Cooperation: A relationship in which organisms work together to achieve a common goal.

An organism consists of one or more cells, and has basic needs, growth, reproduction, response to stimuli, and maintenance of homeostasis capabilities.

Prokaryotes are single-celled organisms without a true nucleus, such as bacteria.
Eukaryotes are organisms with cells that have a true nucleus, including plants, animals, fungi, and protists.

The highest taxonomic rank is the domain, which includes Archaea, Bacteria, and Eukarya.
The kingdom is a level below the domain, and includes Monera, Protista, Fungi, Plantae, and Animalia.
Phylum (or Division in plant taxonomy) is a level below the kingdom, grouping organisms based on body structure.
Class is a level below the phylum, grouping organisms based on shared characteristics.
Order is a level below the class, grouping organisms based on evolutionary relationships.
Family is a level below the order, grouping organisms based on shared characteristics.
Genus is a level below the family, grouping organisms based on close evolutionary relationships.
Species is the most specific level, grouping organisms that can interbreed and produce fertile offspring.

Cell is the basic structural and functional unit of life.
Tissue is a group of similar cells performing a specific function.
Organ is a structure composed of two or more types of tissues performing a specific function.
Organ System is a group of organs working together to perform a specific function.
Organism is a living being composed of one or more cells.

Symbiosis is a close and often long-term relationship between different species, including mutualism, commensalism, and parasitism.
Predation is a relationship in which one organism captures and consumes another.
Competition is a relationship in which organisms compete for the same resource.
Cooperation is a relationship in which organisms work together to achieve a common goal.

organisms definition and environment definition and biosphere definition and habitat definition