CSIR-NET Life Science: Short Notes on Sexual Reproduction in Bacteria!

By Neetesh Tiwari|Updated : July 6th, 2021

Are you looking for some short and reliable notes during your CSIR-NET preparations? Then, you have come to a perfect place!

Candidates preparing for their CSIR NET exam might need to get some short study notes and strategies to apply while preparing for the key exam of their life. At this point, We at BYJU'S Exam Prep come up with short notes on the Sexual Reproduction in Bacteria, which comes under the Biochemistry section of the Life Science syllabus

Our experienced subject-matter experts have meticulously designed this set of short notes on Sexual Reproduction in Bacteria to give you the most standard set of study materials to be focused upon. In this cut-throat competitive world, students need to prepare themselves with the best study materials to help them learn and for their future. So, here we are offering the best study notes that are reliable and can be used by the students during their preparations for the upcoming CSIR-NET 2021 exam.

Are you looking for some short and reliable notes during your CSIR-NET preparations? Then, you have come to a perfect place!

Candidates preparing for their CSIR NET exam might need to get some short study notes and strategies to apply while preparing for the key exam of their life. At this point, We at BYJU'S Exam Prep come up with short notes on the Sexual Reproduction in Bacteria, which comes under the Biochemistry section of the Life Science syllabus

Our experienced subject-matter experts have meticulously designed this set of short notes on Sexual Reproduction in Bacteria to give you the most standard set of study materials to be focused upon. In this cut-throat competitive world, students need to prepare themselves with the best study materials to help them learn and for their future. So, here we are offering the best study notes that are reliable and can be used by the students during their preparations for the upcoming CSIR-NET 2021 exam.

Sexual Reproduction in Bacteria (Transformation, Transduction, and Conjugation)

The most common reproduction method in bacteria (sole members of kingdom Monera) is via the asexual method. But this does not mean that bacteria do not exhibit sexual reproduction. Although not frequently, but bacteria do reproduce sexually. The most common types of methods in bacterial sexual reproduction are Transformation, Transduction, and Conjugation.

1. Transformation:

It is the absorption of a DNA segment from the surrounding medium by a living bacterium. Griffith discovered the phenomenon in 1928. Its mechanism was worked out by Avery (1944). Receptivity for transformation is present for a brief period when the cells have reached the end period of active growth. At this time, they develop specific receptor sites in the wall. Normally E. coli does not pick up foreign DNA, but it can do so in calcium chloride. By subjecting E. coli to calcium chloride, the cells become competent, meaning there are transient pores in the bacterial cell wall from where the foreign DNA can enter the bacterium. 

byjusexamprep

2. Transduction:

It is the transfer of foreign genes by means of viruses. Transduction was first discovered by Zinder and his teacher Lederberg (1952) in Salmonella typhimurium. The process also occurs in E. coli and several other hosts. A virus may pick up a host gene in place of its own gene during its multiplication in the host cell. Such a virus is never virulent. Instead, it passes over the gene of the previous host to the new host. Transducing viruses may carry the same genes (restricted transduction) or different genes (generalized transduction) at different times.

byjusexamprep

Difference Between General And Specialized Transduction

GENERAL TRANSDUCTIONSPECIALISED TRANSDUCTION
 In generalized transduction, the bacteriophages (virus) can pick up any portion of the host's genome.In specialized transduction, the bacteriophages (virus) pick up only specific portions of the host's DNA.
In this type of transduction, at first, bacteriophage infects donor cells and begins the lytic cycle.At first temperate bacteriophage enter into donor bacteria. Then its genome gets integrated with the host cell’s DNA at a certain location, remains dormant, and passes from generation to generation into daughter cells during cell division.
When viruses enter the bacterial cells, viruses hijack host cells and synthesize virus components such as the genome, enzymes, capsid, head-tail, and tail fibres. Then viral enzyme hydrolyses host cell DNA into small fragments.The bacteriophage which follows the lysogenic cycle is known as temperate phage.

Generalized Transduction:

byjusexamprep

Specialized Transduction:

byjusexamprep

3. Conjugation:

It was first discovered in Escherichia coli by Lederberg and Tatum (1946). They found that two different types of auxotroph (nutritional mutants) grown together on a minimal medium produced an occasional prototroph (wild type). Cell contact was required for this change. Anderson (1957) observed conjugation between two such bacteria under the electron microscope. Conjugation was later reported in several other bacteria. Bacteria showing conjugation are dimorphic, i.e., they have two types of cells, male (F+) or donor and female (F-) or recipient. The male or donor cell possesses 1-4 sex pili on the surface and fertility factor (transfer factor, sex factor) in its plasmid. The fertility factor contains genes for producing sex pili and other characters needed for gene transfer. Sex pili are 1- 4 narrow protoplasmic outgrowths. Both sex pili and fertility factors are absent in female or recipient cells. If these two types of cells happen to come nearer, a pile of male cells establishes a protoplasmic bridge or conjugation tube with the female cell. It takes 6-8 minutes. Thus, Gene exchange can occur by two methods.

byjusexamprep

 

Short Notes on Sexual Reproduction in Bacteria - Download PDF Now

 

I hope the above article was helpful for you. Keep Upvote this article and share it among your friends!

Check Out: 

Comments

write a comment

Follow us for latest updates