Biology Prefixes and Suffixes: eu-

Euglena
Euglena are eukaryotic protists. They are photoautotrophs with cells containing several chloroplasts. Each cell has a noticeable red eyespot. Gerd Guenther/Science Photo Library/Getty Images

Biology Prefix: eu-

Definition: The prefix (eu-) means good, well, pleasant or true. It is derived from the Greek eu meaning well and eus meaning good.

Examples:

Eubacteria (eu-bacteria) - kingdom in the bacteria domain. Bacteria are considered to be "true bacteria", distinguishing them from archaebacteria.

Eucalyptus (eu-calyptus) - a genus of evergreen tree, commonly called gum trees, that are used for wood, oil, and gum.

They are so named because their flowers are well (eu-) covered (calyptus) by a protective cap.

Euchromatin (eu-chroma-tin) - a less compact form of chromatin found in the cell nucleus. Chromatin decondenses to allow DNA replication and transcription to occur. It is called true chromatin because it is the active region of the genome.

Eudiometer (eu-dio-meter) - an instrument designed to test the "goodness" of air. It is used to measure gas volumes in chemical reactions.

Euglena (eu-glena) - single-celled protists with a true nucleus (eukaryote) that have characteristics of both plant and animal cells.

Euglobulin (eu-globulin) - a class of proteins known as true globulins because they are soluble in saline solutions but insoluble in water.

Eukaryote (eu-kary-ote) - organism with cells containing a "true" membrane bound nucleus. Eukaryotic cells include animal cells, plant cells, fungi and protists.

Eupepsia (eu-pepsia) - describes good digestion due to having the appropriate amount of pepsin (gastric enzyme) in gastric juice.

Euphenics (eu-phenics) - the practice of making physical or biological changes in order to address a genetic disorder. The term means "good appearance" and the technique involves making phenotypic changes that don't alter a person's genotype.

Euphony (eu-phony) - agreeable sounds that are pleasing to the ear.

Euphotic (eu-photic) - relating to the zone or layer of a body of water that is well lit and receives enough sunlight for photosynthesis to occur in plants.

Euplasia (eu-plasia) - the normal condition or state of cells and tissues.

Euploid (eu-ploid) - having the correct number of chromosomes that corresponds to an exact multiple of the haploid number in a species. Diploid cells in humans have 46 chromosomes, which is twice the number found in the haploid gametes.

Eupnea (eu-pnea) - good or normal breathing that is sometimes referred to as quiet or unlabored breathing.

Eurythermal (eu-ry-thermal) - having the ability to tolerate a wide range of environmental temperatures.

Eurythmic (eu-rythmic) - having a harmonious or pleasing rhythm.

Eustress (eu-stress) - a healthy or good level of stress that is considered beneficial.

Euthanasia (eu-thanasia) - the practice of ending a life in order to alleviate suffering or pain. The word literally means a "good" death.

Euthyroid (eu-thyroid) - the condition of having a well functioning thyroid gland. In contrast, having an overactive thyroid is known as hyperthyroidism and having an underactive thyroid is known as hypothyroidism.

Eutrophy (eu-trophy) - the state of being healthy or having well balanced nutrition and development.

Euvolemia (eu-vol-emia) - the state of having the proper amount of blood or fluid volume in the body.

More Biology Terms

For more information on understanding biology terms, see: Understanding Difficult Biology Words, Biology Word Dissections, Glossary of Cell Biology Terms, Anatomical Terms and Body Planes, and Biology Prefixes and Suffixes.