The hereditary material present in the bacterium E.coli is.

Explanation

The hereditary material present in the bacterium Escherichia coli (E. coli) is primarily b. Double-stranded DNA. Let's explain each option and provide more details: Single-stranded DNA (a): While E. coli does contain single-stranded DNA during certain stages of DNA replication, the primary form of its hereditary material is double-stranded DNA. Double-stranded DNA is the stable form that carries the genetic information. Double-stranded DNA (b): This is the correct answer. E. coli, like most organisms, carries its genetic information in the form of double-stranded DNA. The double-stranded DNA molecule in E. coli is located in the nucleoid region within the bacterial cell. DNA (c): This option is essentially the same as option (b), which specifies "double-stranded DNA." DNA, in general, can be either single-stranded or double-stranded. In the context of E. coli, it primarily contains double-stranded DNA. RNA (d): While E. coli does contain RNA as well, especially for processes like transcription and translation, RNA is not its primary hereditary material. The genetic information in E. coli is stored in the form of double-stranded DNA. Correct Answer: The hereditary material present in the bacterium E. coli is primarily "Double-stranded DNA" (b). Summary: The primary hereditary material in the bacterium E. coli is double-stranded DNA. While E. coli does use RNA for various cellular processes, including protein synthesis, its genetic information is primarily encoded in the form of double-stranded DNA, which is located in the nucleoid region of the cell.