Question

Match the strain with the best description 1. Contains an extra chromosomal F plasmid that codes for proteins needed to make a sex pilus. (Click to select) 2. Contains an extra chromosomal F plasmid that carries some E. coli chromosomal genes. Cciekto select) 3 3. Contains an F plasmid that is integrated into the E. coll chromosome. (Click to select) to select)

Answer 1

1. F+ cells contain an extra chromosomal F plasmid that codes for proteins needed to make a sex pilus. 2. Hfr cells contain an extra chromosomal F plasmid that carries some E. coli chromosomal genes. 3. An Hfr strain contains an F plasmid that is integrated into the E. coli chromosome.

Step-by-step explanation:

1. F+ cells contain an extra chromosomal F plasmid that codes for proteins needed to make a sex pilus. The F plasmid is a small circular DNA molecule that is separate from the E. coli chromosome. It carries genes that encode sex pili, as well as factors needed to form a mating bridge or conjugation tube.

2. Hfr cells contain an extra chromosomal F plasmid that carries some E. coli chromosomal genes. During conjugation, one strand of the bacterial chromosomal DNA will be nicked at the original insertion site of the F plasmid.

3. An Hfr strain contains an F plasmid that is integrated into the E. coli chromosome. This results in the transfer of chromosomal DNA along with the F plasmid during conjugation