Written By: Plasmid, in microbiology, an extrachromosomal genetic element that occurs in many bacterial strains. Plasmids are circular deoxyribonucleic acid (DNA) molecules that replicate independently of the bacterial chromosome. They are not essential for the bacterium but may confer a selective advantage.
A gnat /ËnÃ¦t/ is any of many species of tiny flying insects in the Dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae. They can be both biting and non-biting. Most often they fly in large flocks resembling clouds.
These gnats are small, from one to at the very most seven millimetres long. They have slender, darkly colored bodies and dark wings. However, the females of several species are wingless. Their long legs and antennae with eight to 16 segments are typical of many gnats.