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1. FAST REPRODUCTION BY BINARY FISSION ENABLES BACTERIA TO HOW TO
2. FAST REPRODUCTION BY BINARY FISSION ENABLES BACTERIA TO SERIES

FAST REPRODUCTION BY BINARY FISSION ENABLES BACTERIA TO SERIES

The plasmodium may become very large, with millions of nuclei, but, ultimately, when conditions are right, it forms a series of small bumps, each of which becomes a small, fruiting body (a structure that bears the spores). As it feeds, the plasmodium enlarges, and the nuclei divide synchronously about once every 24 hours. The nuclei are in a syncytium, that is, there are no cell boundaries, and the nuclei flow freely in the motile plasmodium.

In the Myxomycetes, the fusion of two haploid gametes or the fusion of two or more diploid zygotes (the structures that result from the union of two sex cells) results in the formation of a plasmodium-a motile, multinucleate mass of cytoplasm. After the nuclear divisions are complete, the cytoplasm separates, and each nucleus becomes encased in its own membrane to form an individual cell. In such cases the nucleus undergoes several mitotic divisions, producing a number of nuclei. Some algae, some protozoans, and the true slime molds ( Myxomycetes) regularly divide by multiple fission. In this instance the egg receives far more cytoplasm than the polar bodies. During the two successive meiotic divisions involved in the production of eggs, a primordial diploid egg cell is converted into a haploid egg and three small haploid polar bodies ( minute cells). This occurs, in fact, in a large number of higher organisms during meiosis-the process by which sex cells ( gametes) are formed: originally each chromosome of the cell is in a pair ( diploid) during meiosis these diploid pairs of chromosomes are separated so that each sex cell has only one of each pair of chromosomes ( haploid).

In some instances of binary fission, there may be an unequal cytoplasmic division with an equal division of the chromosomes. The nucleus then divides, one of the daughter nuclei passes into the bud, and ultimately the two cells separate. In these fungi the cell wall forms a bubble that becomes engorged with cytoplasm until it is ultimately the size of the original cell. Budding yeast cells provide an interesting exception. In the hard-walled cells of higher plants, a median plate forms and divides the mother cell into two compartments in animal cells, which do not have a hard wall, a delicate membrane pinches the cell in two, much like the separation of two liquid drops. In higher organisms ( eukaryotes) there is first an elaborate duplication and then a separation of the chromosomes ( mitosis), after which the cytoplasm divides in two. In bacteria ( prokaryotes) the chromosome (the body that contains the DNA and associated proteins) replicates and then divides in two, after which a cell wall forms across the elongated parent cell. Of the various kinds of cell division, the most common mode is binary fission, the division of a cell into two separate and similar parts.

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FAST REPRODUCTION BY BINARY FISSION ENABLES BACTERIA TO HOW TO