Concept explainers
For bacteria that are
a. Describe the state of the F factor.
b. Which of these cells are donors? Which is the recipient?
c. Which of these donors can convert exconjugants to a donor state?
d. Which of these donors can transfer a donor gene to exconjugants?
e. Describe the results of conjugation (i.e., changes in the recipient and the exconjugant) that allow detection of the state of the F factor in a donor strain.
f. Describe a “partial diploid” and how it originates.
To review:
For bacterial strains
Description for the state of the F factor.
Identification and explanation of donor and recipient cells.
Identification and explanation of donor cells that can convert exoconjugants to donor state.
Identification of the donor that can transfer the donor gene to exoconjugants.
Description of results of conjugation that allow detection of the state of the F factor in the donor strain.
Description on partial diploids.
Introduction:
Conjugation is the process of transfer of the DNA from one donor bacterium to a recipient bacterium. It is also known as lateral gene transfer. Conjugation is always occurring between the donor cell and the recipient cell, it does not occur between two donor cells. The exoconjugant cell is the recipient cell that has a modification in their genome by receiving the DNA from a donor cell in the process of conjugation. During conjugation, bacteria come in contact with the help of sex pilus. The bacterium that has sex pilus is the donor - male bacterium, and the bacterium that lacks sex pilus is the recipient - female bacterium.
The cell that has the ability to donate their DNA is called
Explanation of Solution
The
Hfr (high frequency recombination)
Donor cell is a cell that donates factor/s to another cell by conjugation. Only that bacterial cell which already has the
The
Hfr and
At the time of conjugation, bacterium comes in contact with the help of sex pilus. The bacterium that has sex pilus is the donor - male bacterium, and the bacterium that lacks sex pilus is the recipient - female bacterium. Conjugation tube is formed between the donor and recipient, and F sex factor is transferred from
A bacterium that has two copies of some of its genes (not all) is termed as partially diploid. In a bacterium, one copy of the desired gene is present on the bacterial genome, and another copy may be fused with the plasmid. Now, the bacterial cell possesses one complete set of genes and identical copy of portion of the genome.
Example of formation of partial diploid:
Conclusions:
The bacterium that has plasmid is
The
Hfr and
A bacterium that has two copies of some of its genes (not all) is termed as partially diploid.
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Chapter 6 Solutions
GENETIC ANALYSIS: AN INTEG. APP. W/MAS
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