AP BIOLOGY

Detailed explanation-1: -Plasmids are self-replicating extrachromosomal DNA molecules found in Gram-negative and Gram-positive bacteria as well as in some yeast and other fungi. Although most of them are covalently closed circular double-stranded DNA molecules, recently linear plasmids have been isolated from different bacteria.

Detailed explanation-2: -Solution : Plasmids are extra chromosomal self replicating double stranded closed circular DNA that are present in bacteria. So the correct answer is “ Plasmids"

Detailed explanation-3: -A plasmid is a small circular DNA molecule found in bacteria and some other microscopic organisms. Plasmids are physically separate from chromosomal DNA and replicate independently.

Detailed explanation-4: -Plasmids are extrachromosomal DNA molecules that can potentially be transferred horizontally as well as vertically in bacterial lineages. Plasmids have been shown to code for numerous bacterial phenotypes, the most concerning of which is resistance to commonly used antibiotics.

Detailed explanation-5: -The plasmid DNA contains the origin of replication and therefore it is self-replicative, naturally, while chromosomal DNA replicates with the genome. The chromosomal DNA is vital for proper cell functioning and reproduction, but plasmid DNA is not essential.