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Eukaryogenesis, the process which created the eukaryotic cell and lineage, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The process is widely agreed to have involved symbiogenesis , in which an archeon and a bacterium came together to create the first eukaryotic ...
Eukaryotic cells are found in plants, animals, fungi, and protists. They range from 10 to 100 μm in diameter, and their DNA is contained within a membrane-bound nucleus. Eukaryotes are organisms containing eukaryotic cells. The four eukaryotic kingdoms are Animalia, Plantae, Fungi, and Protista. [12] They both reproduce through binary fission.
Eukaryotic cells have a variety of internal membrane-bound structures, called organelles, and a cytoskeleton which defines the cell's organization and shape. The nucleus stores the cell's DNA , which is divided into linear bundles called chromosomes ; [ 19 ] these are separated into two matching sets by a microtubular spindle during nuclear ...
This process of altering bacteria is known as transformation. [3] Bacteria may also undergo artificial transformation through chemical and biological processes. The introduction of exogenous DNA into eukaryotic cells is known as transfection. [4] Exogenous DNA can also be artificially inserted into the genome, which revolutionized the process ...
The eukaryotic cell cycle consists of four distinct phases: G 1 phase, S phase (synthesis), G 2 phase (collectively known as interphase) and M phase (mitosis and cytokinesis). M phase is itself composed of two tightly coupled processes: mitosis, in which the cell's nucleus divides, and cytokinesis, in which the cell's cytoplasm and cell membrane divides forming two daughter cells.
Some bacteria transfer genetic material between cells. This can occur in three main ways. First, bacteria can take up exogenous DNA from their environment in a process called transformation. [138] Many bacteria can naturally take up DNA from the environment, while others must be chemically altered in order to induce them to take up DNA. [139]
Mitotic DNA synthesis is known to occur when cells are experiencing stress related to DNA replication. [151] Certain loci in the genome, considered common fragile sites (CFS) [ 152 ] or ALT -associated replication defects [ 153 ] can induce replication stress that may lead to MiDAS.
Mitochondrial DNA is a small portion of the DNA contained in a eukaryotic cell; most of the DNA is in the cell nucleus, and, in plants and algae, the DNA also is found in plastids, such as chloroplasts. [3] Human mitochondrial DNA was the first significant part of the human genome to be sequenced. [4]