BIOL 2170 Lecture 25 Quiz (Ch. 19) – Flashcards

Combinatorial control in eukaryotic transcription refers to the fact that: each gene has its own unique enhancers found nowhere else on that chromosome. each gene has a unique combination of several enhancers with each enhancer always binding to multiple different regulatory transcription factors. each gene has a unique combination of several different enhancers. each gene has a unique combination of thousands of different enhancers.

The CRP-cAMP complex binds the lactose operon when: glucose levels and cAMP levels are high. glucose levels are high and cAMP levels are low. glucose levels are low and cAMP levels are high. None of these choices are correct. glucose levels and cAMP levels are low.

Match up the following molecules with their binding sites: 1. RNA polymerase 2. Repressor protein 3. CRP-cAMP 4. Lactose 5. cAMP a. Binds to the repressor b. Binds to the operator c. Binds to the promoter d. Binds to CRP e. Binds to the CRP-cAMP binding site

For the lactose operon, lactose is a(n): activator. promoter. repressor. inducer. operator.

An operon is: a region of DNA consisting of the promoter and operator sequences needed to regulate one or more structural genes. a region of DNA consisting of the promoter, operator, and coding sequence for structural proteins. a single molecule of RNA coding for more than one protein. a region of DNA consisting of the operator and coding sequence for structural proteins. a gene coding for a repressor protein.

For the lactose operon, the CRP-cAMP is a(n): promoter. activator. operator. inducer. repressor.

The lacZ and lacY genes are transcribed when: lactose is present and glucose levels are low. lactose is absent and glucose levels are high. glucose levels are low, regardless of the level of lactose in the cell. glucose levels are high and lactose levels are low. lactose is present, regardless of the level of glucose in the cell.

The human body contains approximately 200 major cell types. They look and function differently from one another because: each expresses a different set of genes. each has a slightly different genome and each expresses a different set of genes. each expresses the same set of genes, but in different orders at different times. each has a slightly different genome.

In prokaryotes, inducers are small molecules that: bind to activators and promote transcription. None of these choices is correct. bind to activators and inhibit transcription. bind to repressors and promote transcription. bind to repressors and inhibit transcription.