Reproduction

Just like all the other ciliates, paramecium also consists of one or more diploid micronuclei and a polypoid macronucleus hence containing a dual nuclear apparatus.The function of the micronucleus is to maintain the genetic stability and making sure that the desirable genes are passed to the next generation. It is also called the germline or generative nucleus.The macronucleus plays a role in non-reproductive cell functions including the expression of genes needed for the everyday functioning of the cell.Paramecium reproduces asexually through binary fission.  The micronuclei during reproduction undergo mitosis while the macronuclei divide through amitosis. Each new cell, in the end, contains a copy of macronuclei and micronuclei after the cell undergoes a transverse division. Reproduction through binary fission may occur spontaneously.It may also undergo autogamy (self-fertilisation) under certain conditions. It may also follow a sexual reproduction process in which there is an exchange of genetic material because of mating between two paramecia who are compatible for mating through a temporary fusion.

There is a meiotic division of the micronuclei during the conduction  which results in haploid gametes and is further passed on from cell to cell. The old macronuclei are destroyed and formation of a diploid micronuclei takes place when gametes of two organisms fuse together.

Paramecium reproduces through conjugation and autogamy when conditions are not favourable and there is a scarcity of food.

However human reproduction is any form of sexual reproduction  resulting in human fertilisation . It typically involves sexual intercourse between  a man and a woman. During sexual intercourse, the interaction between the male and female reproductive system results  in fertilisation of the woman’s ovum by the man’s sperm. These are specialised reproductive cells called gametes  created in a process called meiosis . While normal cells contains 46 chromosomes , 23 pairs, gamete cells only contain 23 chromosomes, and it is when these two cells merge into one zygote cell that genetic recombinant occurs and the new zygote contains 23 chromosomes from each parent, giving them 23 pairs. A typical 9-month gestation period  is followed by childbirth . The fertilisation of the ovum may be achieved by artificial insemination  methods, which do not involve sexual intercourse. Assisted reproductive technology  also exist .

section produced by: Rhoda Achiaah-Adusei