[ **up: [[Biology]] | [[Life (Biology)]]** ] --- # Cellular biology Cellular biology (also called *cytology*) is a branch of [[Biology|biology]] that studies the structure, function, and behavior of cells.[^1] --- All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and functioning of organisms. [[2024-0815. 'An organism is a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life.'|'An organism is a living being that has a cellular structure and that can independently perform all physiologic functions necessary for life.']][^2] [[2024-0815. Higher levels of organisation are built from lower levels (i.e. molecules combine to form cells, cells combine to form tissues, tissues combine to form organs, etc).|Higher levels of organisation are built from lower levels (i.e. molecules combine to form cells, cells combine to form tissues, tissues combine to form organs, etc).]][^3] [^1]: ‘Cell biology’, *Wikipedia*, updated 31 January 2025, https://en.wikipedia.org/wiki/Cell_biology. [^2]: Lindsay M. Biga, et al., ‘1.2. Structural Organization of the Human Body’, *Anatomy & Physiology* (Corvallis, OR: Oregon State University, 2019), https://open.oregonstate.education/aandp/chapter/1-2-structural-organization-of-the-human-body/. [^3]: Lindsay M. Biga, et al., ‘1.2. Structural Organization of the Human Body’, *Anatomy & Physiology* (Corvallis, OR: Oregon State University, 2019), https://open.oregonstate.education/aandp/chapter/1-2-structural-organization-of-the-human-body/.