BIOL 241 Exam 3 Purdue

In eukaryotic gene regulation, which of the following events is likely to be associated with an increase in gene transcription?

Acetylation of lysines histone tails near a transcription unit.

Regarding the helix-turn-helix motif, which of the following statements is correct?

a. This motif allows proteins to bind to specific regulatory DNA sequences.

3) After analyzing the sequence of a gene, you have found that it contains leucine zippers. Based on this, which of the following statements is correct?

a. This gene encodes a protein that forms dimers.

4) The Drosophila DSCAM locus is capable of expressing multiple isoforms. This is accomplished by:

a. Alternative splicing.

5) Regarding siRNA, which of the following statements is incorrect?

a. siRNA usually binds to target mRNA at specific sites in the 3' UTR.

6) The Luria-Delbrück fluctuation test demonstrated that:

a. Spontaneous mutations are random.

7) Regarding xeroderma pigmentosum (XP), which of the following statements is incorrect?

a. XP is caused by mutation in the components of mismatch repair pathway.

8) Which of the following events is most likely to cause translocations?

treating cells with X rays

9) Sequencing the ends of clones from cDNA library is known as?

a. Expressed sequence tag sequencing.

10) Bisulfite sequencing is typically used to determine:

a. The methylation state of DNA in eukaryotic chromosomes.

11) Which of the following techniques can detect the difference between two homologous chromosomes?

a. Restriction fragment length polymorphism.

12) The ChIP (chromatin immunoprecipitation) assays will identify:

a. The sequences of transcription enhancer elements.

14) The dideoxynucleotides (ddNTP) differ from dNTP in:

a. The absence of hydroxyl group at the 3' position.

16) Which of the following approaches can be used to introduce specific changes in Drosophila genome?

a. Injecting embryos with specific gRNA and Cas9 nuclease.

15) Which of the following statements accurately describes the advantage of using RNAi in a genetic screen?

a. The identification of genes affected by RNAi is instantaneous.

19) To generate mouse mutants by homologous recombination, researchers often make a targeting construct, which contains a flanking thymidine kinase gene. The purpose of this thymidine kinase gene is to:

a. Serve as a marker to selecting ES cells with constructs integrated by homologous recombination.

What is the order of genes?

upstream to downstream

What is the nature of lin-4 gene product?

MicroRNA

a. How does lin-4 regulate lin-14 expression?

The lin-4 microRNA binds to the 3'UTR of lin-14 mRNA, and inhibits its translation.

a. This complex uses energy from ATP hydrolysis to alter chromatin conformation.

SWI/SNF remodeling complex

a. This complex represses transcription by removing acetyl groups from the histone tails in the nucleosome core.

HDAC (histone deacetylation complex)

a. This E. coli enzyme can use blue light energy to directly repair T^T dimers.

Photolyase

a. This E. coli enzyme can directly repair damaged DNA bases caused by ethylmethane sulfonate

Alkyltransferase

a. This complex incorporates one of the strand from 21bps dsRNA and facilitates its binding to target mRNA.

RISC (RNA-induced silencing complex)

Cleaves injected dsRNA into short 21 bp of dsRNA

Dicer

Modifies adenines at specific sequence and allows the E.coli mismatch repair system to distinguish between old and new DNA strands.

dam methylase

Technique to assess mutagenicity of different chemicals

Ame's test

Technique to identify genes based on their distributions in specific tissues

Enhancer trap screen

Technique to identify genes based on their abilities to physically interact with bait proteins

Yeast 2-hybrid screen

Technique to determine whether two mutants with similar phenotypes are allelic

Complementation test

Technique to perform a genome-wide comparison of mRNA levels between cells at two different states.

Microarray analysis (gene chip)

While analyzing the function of an unknown eukaryotic gene, you noticed that it contains leucine zippers. Based on this information, this gene is likely to...

Code for a protein that forms dimers

The human disease xeroderma pigmentosum is caused by disruption of

nucleotide excision repair pathway (NER)

Which of the following describes the generation of expressed sequence tags (ESTs)?

sequencing ends of cDNA clones

Horizontal gene transfer is likely facilitated by

The transformation by DNA from closely related species

Which is an example synteny?

E.coli and B. subtilis exhibit similar gene density

Comparing human and C.elegans genomes, which of the following features is similar?

The average size of introns