Question

The part of the bacterial chromosome that is homologous to a genome fragment transferred from the donor to the recipient cell in the formation of a merozygote is known as
A) Endogenote
B) Dysgenic
C) Exogenote
D) None of these

Answer 1

Bacterial cells can become merozygotes by natural processes like conjugation and also by various laboratory procedures. Plasmid transfer is one of the simplest processes by which they share DNA.

Complete answer:
In this kind of horizontal gene transfer, the bacterial genome itself does not contain any donor material. The transfer is being done from the donor cell to the bacterium. The bacteria is therefore the recipient, it does not contain any foreign DNA as yet. The only point is that the bacterial cell contains a stretch of DNA that is homologous or “matching” with the foreign or donor DNA that is being inserted into the bacterium.
Dysgenic means anything that can affect succeeding generations in a negative or detrimental way. This is because certain undesirable characteristics may be inherited. This doesn’t apply here as the question is about fragments of DNA.
The DNA that is coming in from another cell is known as the exogenote, where “Exo” stands for external or from the outside. This could come from any cell type: mammalian, invertebrate, another bacterium, and so on.

Hence the correct answer is option ‘A’.

Note: As the bacteria cell now contains DNA from another cell, it is considered to be partially diploid. That’s why it is known as a merozygote. In the natural state, bacterial cells are haploid.