CELL STRUCTURES AND FUNCTION
CELL DIVISION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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certain genes are activated
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p53 triggers apoptosis
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cyclins are activated to progress through the cell cycle
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the mitotic spindle pulls chromosomes to opposite sides of the cell
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Detailed explanation-1: -Cell differentiation is caused by changes in gene expression. This occurs when different signaling molecules in the environment activate or repress different transcription factors that are necessary to express certain genes in the DNA. DNA is organized inside cells into chromosomes.
Detailed explanation-2: -Cellular differentiation is a complex process that involves the coordinated regulation of genes by a multitude of cellular pathways. Differentiation is controlled a number of DNA binding proteins that are aberrantly expressed in PDAC.
Detailed explanation-3: -Activation of a gene-transcription-is kicked off when proteins called transcription factors bind to two key bits of DNA, an enhancer and a promoter.
Detailed explanation-4: -When cells express specific genes that characterise a certain type of cell we say that a cell has become differentiated. Once a cell becomes differentiated it only expresses the genes that produce the proteins characteristic for that type of cell.
Detailed explanation-5: -Only a fraction of the genes in a cell are expressed at any one time. The variety of gene expression profiles characteristic of different cell types arise because these cells have distinct sets of transcription regulators. Some of these regulators work to increase transcription, whereas others prevent or suppress it.