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9 Σεπ 2024 · Mitosis, a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical daughter cells. Strictly applied, the term is used to describe the duplication and distribution of chromosomes, the structures that carry the genetic information.
The first step involves RNA polymerase, an enzyme that unwinds and unzips the double helix to access a protein-coding gene. The gene's DNA sequence is used as the template for transcribing an RNA copy of that gene, which the polymerase assembles from a chain of nucleotides.
Mitotic divisions create two new daughter cells with the same chromosome complement as the mother cell. Meiosis, on the other hand, results in daughter cells with half the number of chromosomes...
Mitosis occurs in the following circumstances: Development and growth: The number of cells within an organism increases by mitosis. This is the basis of the development of a multicellular body from a single cell, i.e., zygote and also the basis of the growth of a multicellular body.
Cells Produce Several Types of RNA. The majority of genes carried in a cell's DNA specify the amino acid sequence of proteins; the RNA molecules that are copied from these genes (which ultimately direct the synthesis of proteins) are called messenger RNA (mRNA) molecules.
Animal cell mitosis is divided into five stages—prophase, prometaphase, metaphase, anaphase, and telophase—visualized here by light microscopy with fluorescence. Mitosis is usually accompanied by cytokinesis, shown here by a transmission electron microscope.
20 Σεπ 2022 · RNA modifications have been used to allow mRNA vaccines to evade the innate immune response. RNA is also ‘edited’ by cytosine and adenosine deamination, to form uracil and inosine, respectively.
