define fertile male method
Answers
Fertility is the natural capability to produce offspring. ... Fertility differs from fecundity, which is defined as the potential for reproduction (influenced by gamete production, fertilization and carrying a pregnancy to term). A lack of fertility is infertility while a lack of fecundity would be called sterility.
Fertile male method in bacteria occur as following
The F+ plasmid or fertility factor of the donor cell gets integrated to bacterial chromosome or DNA. The attachable plasmid is known as episome. The point at which plasmid gets integrated to bacterial chromosome differs in different strains. Integration is possible because certain nucleotide sequences present in bacterial chromosome are compatible with sequences in plasmid DNA.
The donor cell having fertility factor integrated to its chromosome is called Hfr (high frequency of recombination), meta male or super male because it has a recombination frequency of 1000 times more as compared to normal F+.
Non-integrated F+ plasmids disintegrate in her cells. The integrated F+ factor breaks the bacterial chromosome at one end of its attachment. The bacterial chromosome now undergoes replication.
A copy of the freed end of bacterial chromosome (end distal to F+ factor, also called zero end) passes into the recipient cell through the conjugation tube. Fertility factor is the last to do so.
Generally whole of bacterial chromosome does not pass into recipient cell. F+ factor is very rarely transferred as conjugation is maintained for a brief period. Only a few genes are transferred, one in seven minutes, two in nine minutes, three in ten minutes, four in eleven minutes, etc..
Conjugation produces an incompletely diploid “zygote” known as merozygote or partial zygote. The new genes may replace the genes present in the recipient cells (those of the recipient cells disintegrate) or get added to them.
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