All life on Earth (the sum of all ecosystems on earth)

Biosphere / Ecosphere

The study of energy and matter cycles in an ecosystem.

Ecosystem Ecology

An ecosystem describes the interactions between groups of organisms from all biological domains and nonliving things in a shared geographical space.

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- Atom
- Molecule
- Macromolecule
- Cell
- Tissue
- Organ
- Organ system
- Organism
- Population
- Community
- Ecosystem
- Biosphere / Ecosphere

Traditional Biological Organisation Scheme

Any living thing that functions as a singular entity

Organism 

In biological taxonomy, a domain is the highest taxonomic rank widely accepted for the classification of organisms.

Domain (biology)

Solomon, Eldra P.; Berg, Linda R.; Martin, Diana W. (2002), Biology (6th ed.), Brooks/Cole, ISBN 0-534-39175-3, LCCN 2001095366

Biology by Solomon, Berg, and Martin

Molecule 

The smallest piece of a chemical element or ordinary matter

Atom

The cell is the fundamental unit of life. While cells vary significantly in size, shape, structure, and function—categorized primarily into prokaryotic and eukaryotic cells—they all share a few fundamental components at their simplest level of construction. The internal structures of a cell are analogous to the organs inside a human body, with unique components suited to specific functions.

Cell

Tissue

A group of tissues with a similar function

Organ

A group of organs that work together to execute one or more functions.

Organ system

A group of organisms that are (1) the same species (2) in a shared geographical area, and (3) able to interbreed

Population (Biology)

Groups of populations of different species that interact with each other.

Community (Biology)

There are many types of macromolecules such as: 

- carbohydrates
- lipids
- proteins
- nucleic acids

Types of Macromolecules

Symbiosis is any close relationship shared by two biological organisms of different species (called symbionts).

Symbiosis (long term interspecific interactions)

Developed in the 17th century following early observations of microscopic life, the cell theory is a foundational scientific principle. It posits three main claims: the cell is the fundamental unit of life, all living organisms contain at least one cell, and new cells can only arise from pre-existing cells.

Cell Theory

In modern genetics-based taxonomy, life is categorized into three domains above the kingdom level: Archaea, Bacteria, and Eukarya. Based on the analysis of small subunit ribosomal RNA (rRNA) gene sequences, this phylogenetic model suggests all three evolved from a common ancestral cell type, but is skewed to show that Archaea and Eukarya share a closer evolutionary relationship with each other than either does to Bacteria.

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