conjugation on paramaecium?

Question

explain to me pls the process of conjugation on paramaecium. more detail = better. tq

Answer 1

1.Formation of Cytoplasmic bridge
The paramoecia that undergo conjugation are calle conjugants.The conjugants come close and unite.The pellicle that separates them dissolves.Their cytoplasmbecomes continuous and this is called cytoplasmic bridge.
2.Formation of pronuclei
In the conjugants, the macronucleus dissolves and micronucleus undergoes meiosis to form 4 haploid daughter nuclei. Three of them dissapear(provide food to the other).the other micronucleus divides and forms one small and one large nucleus. Small nucleus is called male pronucleus and the large one is called female pronucleus.
3.Formation of Synkaryon
The male pronucleus of one conjugant moves through the cytoplasmic bridge into the other conjugant and fuses with the female pronucleus.After this , the female pronucleus is called synkaryon or zygote nucleus. The conjugants now separate and are called exconjugant.
4. Formation of macro and micro nuclei
In each exconjugant, synkaryon divides thrice by mitosis and forms 8 nuclei. of these 3 disintegrate. Of the remaining 5 nuclei, 4 form macronuclei and 1 forms micro nuclei.
5.Division of each exconjugant into 4 daughter paramoecia:
Each exconjugant, with a single micronucleus and four macronucei divides twice to form four daughter paramoecia. Each paramoecium receives one macronucleus from th eexconjugant. The single micro nucleus of the exconjugant divides twice along with exconjugant and each daughter paramoeciumreceives one micronucleus. Thus each of the four daughter paramecia receive one macro and one micro nuclei. Note that only the micronucleus of the exconjugants undergoes mitotic division while the macro nucleus does not divide. They are distributed to the daughter Paramoecia from the exconjugant. By conjugatin a single paramoecium four daughter paramoecia.

Answer 2

Asexual Reproduction
Paramecium, like other ciliates, usually reproduces by splitting in two, forming two virtually identical individuals from one organism. Most ciliates divide transversely, splitting in two by pinching off in the middle of the long axis of the organism. The macronucleus does not divide by mitosis, rather it elongates and then splits in two, roughly one half going to the each of the new daughter cells. This type of reproduction involves no exchange of genetic material, and is a type of asexual reproduction. This form of asexual reproduction is often called 'fission'.


Sexual Reproduction
Under certain conditions, such as overcrowding or environmental stress, Paramecium turns from strictly asexual reproduction to sexual reproduction. Sexual reproduction involves the exchange of genetic material between two individuals of different 'mating strains'. Through a process called conjugation, two paramecia line up side by side and then fuse together. All but one of the cell's micronuclei disintegrate. This micronucleus then divides* into four – one of which will be exchanged during conjugation.