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.
The main difference between a grasshopper and a cricket is that crickets tend to have long antennae, grasshoppers have short antennae. Crickets stridulate (sing) by rubbing their wings together, while grasshoppers stridulate by rubbing their long hind legs against their wings. Grasshoppers detect sound by means of little 'ears' at the base of their abdomen; in crickets these are on the front legs.