A plasmid that is attached to the cell membrane or integrated into the bacterial chromosome is called an episome (q.v.). Plasmids are extremely valuable tools in the fields of molecular biology and genetics, specifically in the area of genetic engineering (q.v.).
A gerund is a form of a verb used as a noun, whereas a participle is a form of verb used as an adjective or as a verb in conjunction with an auxiliary verb. In English, the present participle has the same form as the gerund, and the difference is in how they are used. When used with an auxiliary verb (is walking), it serves as a verb and is the present participle. When used as an adjective (a walking contradiction) it is also a participle.
Participles: participles are part of the verb, and they are a different part of speech. That is, they come from the verb, but they cannot be used as verbs (they don't have subjects, for example). They are often used as adjectives in German.German has two types of participles: present and past.ne can run (run is the verb), or one can run quickly (run is the verb, quickly the adverb). You can have an egg (noun), a cooked egg (egg is the noun, cooked the adjective), or a well cooked egg (egg is the noun, cooked is the adjective describing what type of egg, and well is an adverb describing how it is cooked).