Why is there variation in the bacteria?

Why is there variation in the bacteria?

Many of the observed — but still unexplained — variable phenotypes reported within bacterial research are likely to originate from the feedback structure within the regulatory pathway. Phenotypic variability is a way to increase the fitness of the population, especially under fluctuating environmental conditions.

What are two variations that bacteria might have?

This can occur in two ways: (1) recombination, or integration of the transferred DNA into the bacterial chromosome; or (2) establishment of a plasmid, i.e., the transferred material essentially forms a minichromosome capable of autonomous replication.

What are the sources of genetic variation in bacteria?

For a given population, there are three sources of variation: mutation, recombination, and immigration of genes. However, recombination by itself does not produce variation unless alleles are segregating already at different loci; otherwise there is nothing to recombine.

Why do bacteria have such high genetic variation?

In addition, mutations contribute to genetic diversity in a population. In prokaryotes, horizontal gene transfer (HGT), the transfer of genetic material from one organism to another organism within the same generation, is an important way to promote genetic diversity.

What is the major source of variation in bacteria?

Bacteria mainly reproduce asexually. Cells enlarge, copy their DNA, and divide into two new cells. The only source of variation, therefore, is mutation, and each mutation must accumulate with other mutations, one after another, before a new combination of genes is possible.

How do viruses and bacteria acquired variation?

Viruses undergo evolution and natural selection, just like cell-based life, and most of them evolve rapidly. When two viruses infect a cell at the same time, they may swap genetic material to make new, “mixed” viruses with unique properties. For example, flu strains can arise this way.

Can a virus carry bacteria?

Summary: Bacterial viruses, called bacteriophages, are simple genetic machines, relying on their bacterial hosts to replicate and spread. But scientists have found hundreds of huge phages that carry a slew of bacterial proteins that the phages evidently use to more efficiently manipulate their microbial hosts.

Can virus change to bacteria?

When the virus enters a living cell (a human cell, if the virus infects humans, or a bacterial cell, if the virus infects bacteria) it reprograms that cell and turns the cell into a virus factory.

What is the meaning of variation in bacteria?

BACTERIAL VARIATION Any change in the genotype of a bacterium or its phenotype is known as variation. Genotypic variation can occur as a result of changes in the genes by way of mutation, loss or acquisition of new genetic elements. These variations are heritable.

When do phenotypic variations occur in a bacterium?

Phenotypic variations are seen temporarily when bacteria are grown under certain environmental conditions. These variations are not heritable. Heritable variations: Mutation:A gene will mutate spontaneously, about once in a hundred million cell divisions. Such bacteria are called mutants.

What does S-R variation in Salmonella typhi mean?

S-R variation in Salmonella typhi that is characterized by loss of O antigen and change in colony morphology to rough type. Production of flagella in Listeria monocytogenes occurs at temperature less than 20 o C.