genetics exam 3 practice

a

3' end

b

5' end

e

A chromosome with its centromere in the middle is a a. submetacentric b. acrocentric c. telocentric d. holocentric e. metacentric

a

A functional protein would contain the information coded for within which of the following region of DNA? a. exons b. introns c. enhancers d. promoters e. all of the answers are correct

d

A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to histones. What effect would you expect this mutation has on the expression of this gene? a. the expression of the gene would be abnormally high. b. the effect on gene expression is impossible to predict. c. the gene would encode a different protein instead d. the expression of the gene would be abnormally low or absent e. the promoter of the gene will be constantly available to transcription factors and RNA polymerase

b

A protein _________________ is a compact and stable folded region of a polypeptide. a. tertiary b. domain c. family d. helix e. covalent modification

c

A protein domain is conserved between different members of a protein _______________ a. tertiary b. domain c. family d. helix e. covalent modification

a

Alternative splicing allows an organism to ______________. a. carry fewer genes b. carry more genes c. produce fewer gene products d. more than one of the answers

a

Attaches adjacent Okazaki fragments, forming a continuous DNA strand a. DNA ligase b. DNA polymerase II c. topoisomerase d. DNA polymerase I E. DNA primase

d

Base

b

Because of the number of hydrogen bonds that hold the two strands of a DNA molecule together, unique strands require varying amounts of energy to be separated. Because of the this, each unique DNA molecule "melts" at a different tempearture. In this context, Tm, melting temperature, is the point at which two strands separate, or become denatured. Which DNa sequence listed below would have the lowest Tm? a. GGCGCACC b. TATTGTCT c. GACTCCTG d. CTAACTGG

b

CpG islands are associated with which of the following? a. nucleosome location b. DNA methylation c. steroid hormone activity d. cAMP pathway

c

DNA helicase

b

DNA polymerase

a

Each new DNA strand is initiated by a a. Short RNA primer b. single-stranded DNA-binding protein c. precursor fragment d. restriction fragment e. specific DNA primer

c

Following transcription the RNA has an almost identical sequence (U instead of T) of which of the following? a. regulatory sequences b. termination sequences c. the coding strand of DNA d. the template strand of DNA e. none of these answers

b

For the following five sequences, what is the consensus sequence? 5'-GGGAGCG-3' 5'-GAGAGCG-3' 5'-CAGTGCG-3' 5-GAGAACG-3' 5'-GAGAGCA-3' a. 5'-GGGAGCG-3' b. 5'-GAGAGCG-3' c. 5'-GAGTGCG-3' d. 5'-GAGAACG-3'

d

How many Barr bodies would be present in white blood cells of an individual of karyotype 48, XXYY? a. 4 b. 3 c. 2 d. 1

c

Hydrogen bond

c

If guanine makes up 23% of the nucleotides in a sample of DNA, then thymine would make what percentage of the bases? a. 15 b. 22 c. 27 d. 30 e. 40

b

Phosphate

e

Post-translation, ___________________ further modulates the structure and function of proteins. a. tertiary b. domain c. family d. helix e. covalent modification

a

RNA capping

e

RNA primer

a

RNA splicing

a

Sugar

b

The N-terminal tail of the histone H3 can be extensively modified, and depending on the number, location, and combination of these modifications, these changes may promote the formation of heterochromatin. What is the result of heterochromatin formation? a. increase in gene expression b. gene silencing c. recruitment of remodeling complexes d. displacement of histone H1

e

The alpha helices and beta sheets are examples of protein ______________ structure a. sheet b. quaternary c. primary d. subunit e. secondary

b

The number of distinct protein species found in humans and other organisms can vastly exceed the number of genes. This is largely due to ________________. a. protein degradation b. alternative splicing c. homologous genes d. mutation

a

The phenomenon known as "RNAi" (RNA interference) is used experimentally to a. reduce expression of a specific target gene b. reduce transcription rate from a specific gene promoter c. interfere with replication d. enhance gene expression

e

The semisterility of genotypes heterozygous for a reciprocal translocation results from the lethality due to the chromosomal abnormalities produced by a. alternate segregation b. adjacent-1 segregation b. adjacent-2 segregation d. A and B e. B and C

a

The three-dimensional conformation of a protein is its ______________ structure a. tertiary b. domain c. family d. helix e. covalent modification

a

Transcription

c

Translation

b

What basal transcription factor is most often directly affected by regulatory/specific transcription factors? a. TFIIB b. TFIID c. TFIIE d. TFIIF

a

Which DNA sequence important for gene expression is usually found within the NFR? a. core promoter b. CREB binding site c. histone binding site d. transcription termination sequence e. hormone response element

a

Which of the following allows the RNA polymerase II to interact with enhancers and specific transcription factors? a. mediator b. TFIIB c. TFIIH d. sigma factors e. none of the answers are correct

d

Which of the following function do you not expect to find in the set of genes found in all living organisms on Earth? a. DNA replication B. DNA repair C. protein production d. RNA splicing

c

Which of the following provides for a higher level of stability in the mRNA? a. alternative splicing b. RNA editing c. 3' polyA tailing d. trimming

c

Which of the following reactions are known to be carried out by a ribozyme? a. DNA synthesis b. transcription c. tRNA trimming d. protein hydrolysis e. polysaccharide hydrolysis

b

Which of the following structural motifs promotes dimerization? a. zinc finger b. leucine zipper c. helix-turn-helix d. helix-loop-helix

d

okazaki fragment

b

primase

a

single-strand binding protien

a

sliding clamp

b

A protein such as hemoglobin has ______________ structure a. sheet b. quaternary c. primary d. subunit e. secondary

d

A protein such as hemoglobin, which is composed of more than one protein _______________ a. sheet b. quaternary c. primary d. subunit e. secondary

c

A protein's amino acid sequence is known as its _______________ structure. a. sheet b. quaternary c. primary d. subunit e. secondary

a

Polyadenylation

c

Your friend works in a lab that is studying why a particular mutant strain of Drosophila grows an eye on its wing. Your friend discovers that this mutant string of Drosophila is expressing a transcription factor incorrectly. In the mutant Drosophila, this transcription factor, which is normally expressed in the primordial eye tissue, is now misexpressed in the wing primordial wing tissue, thus turning on transcription of the set of genes required to produce an eye in the wing primordial tissue. If this hypothesis is true, which of the following types of genetic change would most likely lead to this situation? a. a mutation within the transcription factor gene that leads to a premature stop codon after the third amino acid b. a mutation within the transcription factor gene that leads to a substitution of a positively charged amino acid for a negatively charged amino acid c. a mutation within an upstream enhancer of the gene's promoter d. a mutation in the TATA box of the gene