THE MOLECULAR BASIS OF INHERITANCE
DNA MAKES RNA MAKES PROTEIN
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Promoters determine whether a gene is expressed.
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Expressed genes make more DNA.
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DNA-binding proteins determine whether a gene is expressed.
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RNA polymerase regulates gene expression.
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Detailed explanation-1: -Which of the following is true regarding gene regulation in prokaryotes such as bacteria? Prokaryotic genes are usually transcribed as a group and have a single promoter. Bacterial genes are often clustered in a chromosome and are transcribed from one promoter as a single unit.
Detailed explanation-2: -For prokaryotes, most regulatory proteins are negative and therefore turn genes off. Here, the cells rely on protein–small molecule binding, in which a ligand or small molecule signals the state of the cell and whether gene expression is needed.
Detailed explanation-3: -Final answer: d. They can act both as activators and as repressors.
Detailed explanation-4: -Gene Regulation in Prokaryotes The regulation usually takes place in the expression of the RNA polymerase at the promoter site. This affects the accessory proteins which bind to the recognition sites. These accessory proteins can regulate the promoter site in two ways: Positive regulation by activators.