Mastering Biology Quiz 12 – Flashcards

In eukaryotes, the first step in the control of gene expression is ______. A.transcription B.mRNA stability control C.RNA processing D.chromatin remodeling

Are histone deacetylases (HDACs) associated with negative or positive control of gene expression? Why? A. Positive control, because they make mRNA more accessible for translation B. Negative control, because they make DNA less accessible for transcription C. Negative control, because they make mRNA less accessible for translation D. Positive control, because they make DNA more accessible for transcription

Which answer best explains how certain patterns of histone acetylation or DNA methylation could influence whether a cell became a muscle cell or a brain cell? A. They could determine what sets of genes are found in different cell types. B.They could affect which sets of genes are transcribed in different cell types. C. They could produce different patterns of post-translational control in different cell types. D. They could produce differences in the DNA sequences of genes found in different cell types.

The addition of acetyl groups to histones is associated with ______. A. chromatin decondensation and low levels of gene expression B. chromatin condensation and low levels of gene expression C. chromatin decondensation and higher levels of gene expression D. chromosome condensation and high levels of gene expression

A mechanism of inheritance that does not depend on differences in DNA sequence is ______. A. chromatin remodeling inheritance B. epigenetic inheritance C. histone H1-mediated inheritance D. nucleosomal inheritance

Differential gene expression is the result of different cells containing different ______. A. regulatory proteins B. genes C. nucleosomes D. regulatory sequences

Regulatory transcription factors _____. A. influence the degree of unwinding of DNA at the promoter B. influence the assembly of the basal transcription complex C. open the two strands of DNA so that RNA polymerase can begin transcription D. influence the binding of sigma factor to DNA

If cells of an individual contain the same set of genes, how do these cells become different from each other during development? A. Different cell type-specific regulatory elements in DNA are created during development. B. Differences develop in promoter sequences that lead to different signals being produced by each type of cell. C. Different cell type-specific regulatory elements in DNA are selectively lost during development. D. Differences in extracellular signals received by each cell lead to differences in the types of regulatory proteins present in each cell.

Alternative RNA splicing allows for the number of different _________ to exceed the number of different __________. A. proteins; genes B. primary transcripts; genes C. genes; proteins D. primary transcripts; mRNAs

MicroRNAs work to ______. A. destroy mRNA or block its translation B. increase rates of transcription C. decrease the binding of ribosomes to the 5' cap D. control patterns of alternative splicing

Why are loss-of-function mutations in p53 observed in over half of all human cancers? A. p53 normally functions as a proto-oncogene that encourages cell growth by triggering specific phases of the cell cycle. B. p53 normally functions as a tumor suppressor to stop the cell cycle after DNA damage occurs. C. p53 normally functions as a proto-oncogene to stop the cell cycle after DNA damage occurs. D. p53 normally functions as a tumor suppressor that encourages cell growth by triggering specific phases of the cell cycle.