Glossary - The biosphere and its diversity

Cell: The cell is the smallest and simplest unit of living beings. It is formed by the plasma membrane, the cytoplasm and the genetic material, and is capable of performing the vital functions of nutrition, interaction and reproduction. Therefore, it is said to be the structural and functional unit of living beings.

Prokaryotic cell: A prokaryotic cell is small (1-10 µm), having the genetic material dispersed in the cytoplasm and having no cellular organelles.

Eukaryotic cell: A eukaryotic cell is of relatively large (10-100 µm), having the genetic material protected by the cell nucleus and having numerous cellular organelles.

Plant cell: Eukaryotic cell that is characterized by having a thick cell wall, chloroplasts in which photosynthesis is performed and large vacuoles in which different substances are stored.

Animal cell: Eukaryotic cell that is characterized by not having a thick cell wall, presenting cilia or flagella that allow it to move and having small vacuoles in which different substances are stored.

Unicellular organism: Organism formed by a single cell. Most unicellular beings are prokaryotes, such as bacteria, but there are some unicellular eukaryotic beings, such as protozoa and unicellular algae.

Multicellular organism: Organism formed by two or more cells. All multicellular beings are eukaryotes, like animals, plants and most fungi.

Autotrophic organism: An organism capable of synthesizing all the nutrients it needs to live from inorganic substances. For this they perform a process called photosynthesis or chemosynthesis.

Heterotrophic organism: An organism that obtains all the nutrients it needs to live from organic substances. For this it feeds on other living beings.

Asexual reproduction: Reproductive process for which only one parent is needed and all their offspring are genetically identical. It occurs in bacteria, protists, fungi and, in some cases, invertebrate plants and animals.

Sexual reproduction: Reproductive process for which two parents are needed and the offspring have characteristics of both due to the union of the gametes of the parents. It occurs in protists, fungi, plants and animals.

Vital functions: The set of processes that all living beings carry out to stay alive. They are nutrition, interaction and reproduction.

Nutrition: The set of processes by which living beings obtain the matter and energy they need to live. Depending on their nutrition, living things can be autotrophic or heterotrophic.

Interaction: The set of processes by which living beings are able to detect stimuli or changes in the environment and respond to them.

Reproduction: The set of processes through which animals can have offspring. Reproduction can be asexual or sexual.

Biodiversity: The set of all living beings that inhabit a certain environment, such as an ecosystem, a region or the Earth.

Taxonomy: It is the branch of Science that classifies living beings according to their degree of kinship.

Taxon (plural, taxa): It is each of the categories used to classify living beings. Those who are part of the same taxon are related to each other. There are seven taxa: Kingdom, Phylum, Class, Order, Family, Genus, and Species.

Species: The set of similar living beings that can reproduce among themselves and produce fertile offspring.

Binomial nomenclature: A set of rules created by Linnaeus that assign a scientific name to each living being. This avoids the variety of common names that can be assigned to each living being according to each language or region.

Scientific name: Name made up of two words that allows each living being to be identified as if it had name and surname. The first word indicates the name of the genus and the second indicates the name of the species. 

You can read the Spanish version of this glossary here.