Biology 1225 Chapter Notes - Chapter 7: Guanine, Cytosine, Lactose Intolerance
29 Mar 2018
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Cell"s usually use 10% of genes at one time. Control over gene expression is important because it allows individual cells to respond. Transcription factors: affect whether/how fast gene is transcribed appropriately to changes in their internal and external environments. Master gene expression controls the establishments of organs and tissues. Gene expression that orchestrates animal development begins with different maternal mrna delivered to different regions of cytoplasm in egg. Mrna translated only after egg is fertilized. Protein products diffuse away : forming gradients that form embryos. Homeotic gene is one type of master gene. Expression directs formation of specific body parts. Knockout: researchers inactivate a gene by introducing a mutation that prevents its. Homeotic genes control development by same mechanisms in all multi-celled eukaryotes expression. Condensation inhibits transcription, most genes not expressed. X inactivation ensures only one of two x in female cells is active -> equalizes.
