GENERAL HISTOLOGY

Detailed explanation-1: -Prokaryotes are organisms whose cells lack a nucleus and other organelles. Prokaryotes are divided into two distinct groups: the bacteria and the archaea, which scientists believe have unique evolutionary lineages.

Detailed explanation-2: -Prokaryotic cells, such as bacteria, have a free-floating chromosome that is usually circular and is not enclosed in a nuclear membrane. Instead, the DNA simply exists in a region of the cell called the nucleoid. Prokaryotic cells only have a small range of organelles, generally only a plasma membrane and ribosomes.

Detailed explanation-3: -Unlike the eukaryotic (true) cells, bacteria do not have a membrane enclosed nucleus. The chromosome, a single, continuous strand of DNA, is localized, but not contained, in a region of the cell called the nucleoid. All the other cellular components are scattered throughout the cytoplasm.

Detailed explanation-4: -In organisms such as humans, DNA is organised into structures called chromosomes inside a nucleus, a membrane-bound compartment within each cell. Bacteria lack a nucleus, and how bacterial DNA is organised has puzzled biologists for many years.

Detailed explanation-5: -Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. Plasmids have a wide range of lengths, from roughly one thousand DNA base pairs to hundreds of thousands of base pairs.