BIOL 241 Midterm II

A linear chromosome with two centromeres and another linear chromosome with no centromere.

If a cell contains these two homologous chromosomes, a crossover during meiosis in the genomic segment between E and F will generate:

A non-disjunction of X chromosome in mother at meiosis II

In human, red-green color blindless is a X-linked recessive disorder. A Klinefelter (47,XXY) individual and his brother (46,XY) are both color blind, whereas both parents have normal color vision. Based on this, in the absence of meiotic crossovers, which of the following events likely caused the conditions associated with the young man with Klinefelter syndrome?

Which of the following Drosophila crosses will cause hybrid dysgenesis?

Males with P elements mated with females without P element.

The E. coli chromosome contains 4.6kb of DNA. During DNA replication, it has:

1 replicon

In a mixed copolymer experiment, synthetic message was created with 3/4G:1/4C. These messages yielded proteins with the following amino acid compositions. Glycine 36/64 (56%) Alanine 12/64 (19%) Arginine 12/64 (19%) Proline 4/64 (6%) The frequency of the occurrence of GCG and GCC sequences in the RNA polymer is expected to be:

12/64

According to Chargaff's rule, a species with 22% adenine in its genome will have:

22% of thymine in its DNA

In a mixed copolymer experiement, synthetic message was created with 3/4C:1/4G. These messages yielded proteins with the following amino acid compositions: Proline - 36/64 Alanine - 12/64 Arginine - 12/64 Glycine - 12/64 The frequency of the occurrence of GGC sequence in the RNA polymer is expected to be:

3/64

In eukaryotic chromosomal compaction, chromatin organized into solenoid-like structures is known as:

30 nm fiber.

Regarding the methylation of cytosines in CG islands, which of the following statements is correct:

5-methylcytosines typically associate with decrease in gne expression; 5-methylcytosines are typically found in heterochromatic regions; 5-methylcytosines are typically found near imprinted genes; bisulfite sequencing can be used to monitor the DNA methylation state

In group II autocatalytic splicing, the attachment of the branch point to the 5' splice site is mediated by:

A 5'-2' linkage

The addition of the 5'-methylguanosine cap is mediated by:

A 5'-5 linkage

In eukaryotes, a homologous crossover between two direct repeats on the same arm of a chromosome will generate:

A deletion and a circular DNA

In eukaryotes, a homologous crossover between two inverted repeats on the same side of a chromosome arm will generate:

A paracentric inversion.

A deletion of region 4 in Trp operon will likely

Allow the transcription to proceed into trp structural genes even when tryptophan level is high

Regarding the sxl expression in Drosophila adults, which of the following statements is correct:

Alternative splicing of sxl mRNA in adult females generates functional sxl proteins.

Ligase

An enzyme that connects two fragments of DNA to make a single fragment

Bill and Betty have had two children with Down syndrome. Bill's brother has Down syndrome and his sister has two children with Down syndrome. On the basis of these observations, which of the following statements is most likely correct? a. Bill has 47 chromosomes. b. Betty has 47 chromosomes. c. Bill's sister has 45 chromosomes. d. Bill's brother has 45 chromosomes.

Billy carries a Robertsonian translocation of the chr. 21 with chr. 14

In the absence of telomerase, which ends of DNA will be shorteded after one round of DNA replication:

Both 3' ends.

A deletion of region 2 in Trp L will:

Cause the transcription to end after the trp L even when tryptophan level is low

A deletion of the Shine-Dalgarno sequence in trp L will:

Cause the transcription to end after the trp L even when tryptophan level is low

DNA polymerase III

Found as a dimer at the replication fork

The direct repeats found at both ends of transposons are

Generated by staggered cuts of the target sequences during transposition

In a mixed copolymer experiment, synthetic message was created with 3/4G:1/4C. These messages yielded proteins with the following amino acid compositions. Glycine 36/64 (56%) Alanine 12/64 (19%) Arginine 12/64 (19%) Proline 4/64 (6%) Based on these results, GGG codes for

Glycine

An insertion of two nucleotides after region 1 but before region 2 will likely:

Have no effect on trp attenuation.

In a theoretical operon, genes R, S, and T represent the repressor gene, the operator gene, and the structural gene, but not necessarily in that order. This operon is concerned with the synthesis of compound Z. From the data provided in the accompanying table (AE=active enzyme, NE=no enzyme), please answer the following questions: Genotype: Z present; Z absent R+S+T+: NE; AE R-S+T+: AE; AE R+S-T+: NE; NE R+S+T-: AE; AE R-S-T-/ R+S+T+: NE; AE R-S+T+/ R+S-T-: AE; AE R+S-T+/ R-S+T-: AE; AE R+S+T-/ R-S-T+: NE; AE The repressor gene is:

T

Which of the following enzymes is a RNA-dependent DNA polymerase?

Telomerase

During E. coli DNA replication, incorrectly inserted nucleotides can be removed by:

The 3'-5' exonuclease activity of DNA polymerase III

The Ac element in Maize utilizes non-replicative transposition. Based on this, which of the following statements is incorrect?

The Ac element forms cointegrant during transposition.

The Ac element in Maize utilizes non-replicative transposition. Based on this, which of the following statements are correct?

The Ac element is flanked by direct repeats; The Ac element needs a functional transposase for transposition; The mobilization of Ac element generates double-stranded breaks; The Ac element contains the inverted repeats near the ends of the transposon

In Maize, the Ds element cannot mobilize in the absence of Ac element because

The Ds element usually contains a deletion in its transposase gene.

The pelement in Drosophila utilizes non-replicative transposition. Based on this, which of the following statements is incorrect?

The P element forms cointegrant during transposition.

The pelement in Drosophila utilizes non-replicative transposition. Based on this, which of the following statements are correct?

The P element is flanked by direct repeats; The P element needs a functional transposase for transposition; the mobilization of P element generated double-stranded breaks; the P element contains the inverted repeats near the ends of the transposon

In E. coli, insertion sequences insert themselves by generating staggered cuts in the target sites, resulting in:

The formation of flanking direct repeats.

In maize, the Ds elements insert themselved by generating staggered target sites, resulting in:

The formation of flanking direct repeats.

Regarding the splicing of autocatalytic group I introns, which of the following statements in correct:

The process requires a exogenous guanosine as a cofactor.

Regarding tRNA, which of the following statements is correct?

The secondary structure of tRNAs is cloverleaf-shaped; Linking tRNAs to appropriate amino acids is mediated by aminoacyl tRNA synthesis; a tRNA contains anticodon that base-pairs with the codon in mRNA; a charged tRNA has the corresponding amino anid bound to the CCA sequence at the 3' end

Regarding the splicing of autocatalytic introns, which of the following statements is correct?

The splicing of group II introns forms lariats.

Regarding the splicing of mRNA, which of the following statements is incorrect?

The splicing of mRNA is autocatalytic

Regarding the splicing of mRNA, which of the following statements is correct:

The splicing of mRNA requires spliceosomes; the splicing results in the formation of lariats; the introns of mRNA end with AG; the intron in mRNA begin with GU.

The alternative splicing of sxl mRNA regulates its own expression. Which of the following statement best describes this regulation?

The splicing of sxl mRNA in females generates functional Sxl proteins.

Multiple individuals in a pedigree carry Down syndrome. Based on this, which of the following statements is likely correct?

These Down syndrome cases are likely caused by Robertsonian translocations.

Regarding histones, which of the following statements is correct?

They complex with 147 bps of DNA to form nucleosomes

Regarding the formation of lariat, which of the following statements is correct?

This is formed by the branch point and the 5' splice site via a 2'-5' linkage.

Regarding supercoiling, which of the following statements is correct?

Underwound DNA typically exhibits negative supercoils, which are right-handed

Paracentric Inversion

WT chromosome: ABC-DEFG Homologous chromosome: abc-dfeg

Which of the following events is likely to generate a Drosophila gynandromorph?

a. A non-disjunction of X chromosomes in mitosis during early embryonic development.

The phenomena of semi-sterility is caused by:

a. Adjacent segregation of reciprocal translocated chromosomes.

Which of the following activity can remove RNA primers during E. coli DNA replication?

a. The 5'-3' exonuclease activity of DNA polymerase I.

The Avery-MacLeod-McCarty experiment demonstrated that:

a. Treating of heat-treated IIIS bacteria lysate with DNase destroys its ability to transform non-virulent bacteria.

Primase

is an RNA polymerase

SSB protein

prevents reassociation of complementary base pairs

Regarding tRNA, which of the following statements is incorrect?

tRNA contains 5' overhang

Gyrase

topoisomerase that relieves supercoiling ahead of replication fork

Helicase

unwinds the DNA double helix

An operon, controlled by a regulatory molecule R, deals with the synthesis of enzymes capable of metabolizing a compound Z. In the presence of Z, active enzymes are made, whereas no enzyme is made in the absence of Z. When R is inactivated by loss-of-function mutations, no enzyme is made. Based on this, the regulation of this operon is:

Positive, inducible

During DNA replication, which one of the following enzymes has the ability to synthesize RNA using DNA template?

Primase

In a mixed copolymer experiement, synthetic message was created with 3/4C:1/4G. These messages yielded proteins with the following amino acid compositions: Proline - 36/64 Alanine - 12/64 Arginine - 12/64 Glycine - 12/64 Based on these results, CCC codes for:

Proline

In a theoretical operon, genes R, S, and T represent the repressor gene, the operator gene, and the structural gene, but not necessarily in that order. This operon is concerned with the synthesis of compound Z. From the data provided in the accompanying table (AE=active enzyme, NE=no enzyme), please answer the following questions: Genotype: Z present; Z absent R+S+T+: NE; AE R-S+T+: AE; AE R+S-T+: NE; NE R+S+T-: AE; AE R-S-T-/ R+S+T+: NE; AE R-S+T+/ R+S-T-: AE; AE R+S-T+/ R-S+T-: AE; AE R+S+T-/ R-S-T+: NE; AE The operator is:

R

Which of the following factors participates in eukaryotic transcription termination?

RAT exonuclease.

The autonomous replicating sequences (ARS) are

Recognized by origin recognition complex

DNA polymerse I

Removes the primers

Which of the following best describes the regulation of trp operon by trp R

Repressible; negative control

Aminoacyl-tRNA synthetases are responsible for attaching amino acids to tRNAs. If tryptophanyl-tRNA synthetase was partially defective at attaching tryptophan to tRNA (let's say its activity was only 10% of that found in a normal bacterium), how would this affect attenuation of the trp operon?

Ribosomes will stall at the leader and the structural genes will be transcribed

In a theoretical operon, genes R, S, and T represent the repressor gene, the operator gene, and the structural gene, but not necessarily in that order. This operon is concerned with the synthesis of compound Z. From the data provided in the accompanying table (AE=active enzyme, NE=no enzyme), please answer the following questions: Genotype: Z present; Z absent R+S+T+: NE; AE R-S+T+: AE; AE R+S-T+: NE; NE R+S+T-: AE; AE R-S-T-/ R+S+T+: NE; AE R-S+T+/ R+S-T-: AE; AE R+S-T+/ R-S+T-: AE; AE R+S+T-/ R-S-T+: NE; AE The structural gene 1 is:

S

Which of the following sequences will be complementary to 16S rRNA

Shine-Dalgarno sequence