Question 1

Which of the following genes rarely occur in multiple copies?
(I)histone proteins
(II)protein-coding genes
(III)gene clusters

Accepted Answer

Protein-coding genes rarely occur in multiple copies, while histone proteins and gene clusters often do. This is because having extra copies of protein-coding genes can lead to overproduction of certain proteins, which can be harmful to the cell. In contrast, having extra copies of histones and gene clusters can increase the efficiency of DNA packaging and gene regulation, respectively.

Question 2

Considering the E.coli trp operon,which of the following is TRUE? (I)The formation of the 2-3 hairpin is highly favored over the 1-2 hairpin when trp is low. (II)When the concentration of Trp-tRNA^Trp is low,the ribosome halts on tandem Trp codon of segment 1. (III)Formation of the 2-3 hairpin facilitates transcription and translation of the trp operon. IV)The attenuator system has no effect when Trp levels are high.

Accepted Answer

The answer of Considering the E.coli trp operon,which of the...

Question 3

Which of the following is TRUE regarding eukaryotic mRNAs?
(I)They uniformly stable.
(II)The poly (A)tail appears to partially Moderate the rate of degradation.
(III)The 5' cap appears to partially Moderate the rate of degradation.
(IV)They have decay times ranging from 10-30 minutes.

Accepted Answer

Option I is false as eukaryotic mRNAs are not uniformly stable.
Option II is true as the poly (A) tail plays a role in regulating mRNA degradation.
Option III is true as the 5' cap also plays a role in regulating mRNA degradation.
Option IV is false as eukaryotic mRNAs have decay times ranging from several minutes to several hours. Therefore, options II and III are the correct choices.

Question 4

Progression through the cell cycle
(I)is regulated by cyclins.
(II)is controlled by Cdks.
(III)is altered by CKIs.

Accepted Answer

The progression through the cell cycle is regulated by several factors, including cyclins, Cdks, and CKIs. Cyclins are regulatory proteins that control the progression from one phase of the cycle to the next by binding and activating Cdks. Cdks, in turn, phosphorylate specific substrates to carry out the necessary cellular processes. CKIs are proteins that inhibit Cdks, slowing down or stopping the cell cycle progression. Therefore, all options (I, II, and III) are correct, and the best choice is E, which includes all of them.

Question 5

Which of the following are requirements for genetic information?
(I)Information must be tapped in an orderly fashion.
(II)Information must be available to direct responses in changes to internal or external conditions.
(III)Information must be removable following development.

Accepted Answer

Requirement (I) is necessary for accurate coding and decoding of genetic information, and requirement (II) is necessary for proper adaptation to changing conditions. Requirement (III) is not necessary for genetic information, as many traits coded for by genetic information are not removable following development (e.g. eye color). Therefore, the correct answer is B (I,II).

Question 6

In prokaryotes,which of the following are effective at controlling gene expression relative to the concentration of a metabolite or catabolite?
(I)CAP or CRP
(II)long terminal repeats (LTRs)
(III)riboswitches
(IV)SWI/SNF

Accepted Answer

CAP or CRP, LTRs, and riboswitches are all effective at controlling gene expression relative to the concentration of a metabolite or catabolite. SWI/SNF, on the other hand, is a chromatin remodeling complex and is not directly involved in controlling gene expression in response to metabolite or catabolite concentrations. Therefore, the correct choice is C, which includes the three options that are relevant for this question.

Question 7

The process of somatic recombination
(I)results in antibody diversity.
(II)involves selection of individual members of clustered gene sequences.
(III)involves selection and recombination of specific exons on the $\kappa$ and/or $\lambda$ chain.

Accepted Answer

Somatic recombination is responsible for the generation of antibody diversity through the selection and recombination of specific exons on the F1F1F1S1F1F1F10 and/or F1F1F1S1F1F1F10 chain. This process involves the selection of individual members of clustered gene sequences, resulting in a wide variety of possible combinations and further increasing antibody diversity. Therefore, all three statements are correct.

Question 8

Which of the following would likely result in the formation of RNAi?

Accepted Answer

The answer of Which of the following would likely result...

Question 9

On average a single nucleotide polymorphism occurs ____ in humans.

Accepted Answer

Single nucleotide polymorphisms (SNPs) occur approximately every 1000 to 1500 base pairs in the human genome, making option C the closest estimate.

Question 10

Of the human genome approximately 80% ___.

Accepted Answer

Approximately 80% of the human genome may be transcribed, indicating that a significant portion has some level of transcriptional activity, even though not all of it encodes for proteins. This challenges earlier views that a large portion of the genome was "junk DNA" without function.

Quiz 28: Regulation of Gene Expression

Which of the following genes rarely occur in multiple copies? (I) histone proteins (II) protein-coding genes (III) gene clusters

Which of the following is TRUE regarding eukaryotic mRNAs? (I) They uniformly stable. (II) The poly (A) tail appears to partially Moderate the rate of degradation. (III) The 5' cap appears to partially Moderate the rate of degradation. (IV) They have decay times ranging from 10-30 minutes.

Progression through the cell cycle (I) is regulated by cyclins. (II) is controlled by Cdks. (III) is altered by CKIs.

Which of the following are requirements for genetic information? (I) Information must be tapped in an orderly fashion. (II) Information must be available to direct responses in changes to internal or external conditions. (III) Information must be removable following development.

In prokaryotes,which of the following are effective at controlling gene expression relative to the concentration of a metabolite or catabolite? (I) CAP or CRP (II) long terminal repeats (LTRs) (III) riboswitches (IV) SWI/SNF

The process of somatic recombination (I) results in antibody diversity. (II) involves selection of individual members of clustered gene sequences. (III) involves selection and recombination of specific exons on the $\kappa$ and/or $\lambda$ chain.

Which of the following would likely result in the formation of RNAi?

On average a single nucleotide polymorphism occurs ____ in humans.

Of the human genome approximately 80% ___.

Quiz 28: Regulation of Gene Expression

Which of the following genes rarely occur in multiple copies? (I) histone proteins (II) protein-coding genes (III) gene clusters

Which of the following is TRUE regarding eukaryotic mRNAs? (I) They uniformly stable. (II) The poly (A) tail appears to partially Moderate the rate of degradation. (III) The 5' cap appears to partially Moderate the rate of degradation. (IV) They have decay times ranging from 10-30 minutes.

Progression through the cell cycle (I) is regulated by cyclins. (II) is controlled by Cdks. (III) is altered by CKIs.

Which of the following are requirements for genetic information? (I) Information must be tapped in an orderly fashion. (II) Information must be available to direct responses in changes to internal or external conditions. (III) Information must be removable following development.

In prokaryotes,which of the following are effective at controlling gene expression relative to the concentration of a metabolite or catabolite? (I) CAP or CRP (II) long terminal repeats (LTRs) (III) riboswitches (IV) SWI/SNF

The process of somatic recombination (I) results in antibody diversity. (II) involves selection of individual members of clustered gene sequences. (III) involves selection and recombination of specific exons on the κ\kappaκ and/or λ\lambdaλ chain.

Which of the following would likely result in the formation of RNAi?

On average a single nucleotide polymorphism occurs ____ in humans.

Of the human genome approximately 80% ___.

The process of somatic recombination (I) results in antibody diversity. (II) involves selection of individual members of clustered gene sequences. (III) involves selection and recombination of specific exons on the $\kappa$ and/or $\lambda$ chain.