plasmid
UK[ˈplazmɪd]US[ˈplæzmɪd]
n
A genetic structure in a cell, especially a bacterium, that can replicate independently of the chromosomes, typically a small circular DNA strand.
Morpheme Breakdown
plasm
id
plasm
form, mold
id
noun suffix
Etymology
The term 'plasmid' is a modern scientific coinage, constructed from Greek linguistic components. Its core, 'plasm-', derives from the Greek plasma, meaning 'something molded or formed', which itself originates from the verb plassein, 'to mold'. This root is shared with words like 'plasma' (the formative fluid of blood) and 'cytoplasm' (the formative material of a cell). The suffix '-id' is used to form nouns denoting a particle or body. Thus, a 'plasmid' is, etymologically, a 'formed body' or 'molded particle' within a cell, a name that logically describes its distinct, self-replicating physical structure separate from the chromosomal DNA.
Analysis
Structure: plasm (form, mold) + id (noun suffix)
- plasm: From Greek plasma (something molded or formed). In this word, it functions as the root, carrying the core meaning related to a formed substance or entity.
- id: A noun-forming suffix of Greek origin (via Latin -is, -id-), often used in scientific terminology to denote a thing belonging to or connected with a specified class or kind.
Examples
The plasmid was engineered to carry a gene for antibiotic resistance.
Bacterial conjugation often involves the transfer of a plasmid from one cell to another.
Researchers use plasmids as vectors in genetic engineering to introduce new DNA into an organism.