Unit 1 Genetics MCQ

The green box describes the enzymatic pathway that produces arginine. The orange box describes results from testing whether growth of particular mutant strains of yeast can be reduced with precursor to arginine. According to these results, which enzyme does ARG-F code for?

Ornithine transcarbamylase

Mendel’s Law of Independent Assortment accurately describes

The segregation of alleles at genes not physically linked to one another

Which of the following is essential for natural selection to occur?

There must be consistent relationship between an individual’s value of a trait and its survival or reproductive success

James Watson is known for (pick all the apply):

a. publication describing the structure of DNA

b. use of unpublished X-ray diffraction data gathered by Rosalind Franklin

c. racism and misogyny

Single-stranded RNA is composed of a phosphate backbone, …

c. ribose sugar and nitrogenous bases, bound together by covalent bonds.

According to NASA (1979), “life…

is a self-sustaining system capable of Darwinian selection.”

The demonstration that RNAs can copy template RNA by adding triplets of ribonucleotides showed that:

RNAs can have polymerase activity

Which of the following is consistent with the “RNA World” hypothesis

b. The ability of RNAs with modified bases to catalyze small peptides.

Which of the following best describes the most important finding of Frederick Griffith's experiments in which he injected Pneumococcus bacteria into mice?

non-virulent bacteria transformed into virulent bacteria when injected with cell components from heat-killed virulent bacteria

RNase P is an example of:

 catalytic RNA

Which statement is true?

d. RNA is single stranded and can have complex secondary structure

UTP is an example of:

d. a ribonucleotide

Dapi is an example of:

e. a chemical used to visualize DNA

The genetic code

d. is degenerate

The stop codon of a typical eukaryotic protein-coding gene marks…

e. the final codon before an untranslated region is transcribed

The classical “Central Dogma” of molecular biology states that:

a. DNA is transcribed into RNA, which is translated into protein

Modern criticism of the “one gene, one enzyme” hypothesis could include:

a. some genes do not encode proteins

c. some genes can produce more than one protein

d. some genes produce proteins other than enzymes

If a segment of DNA with bases 3’-ATG-CAT-GCC-5’ on the template strand is transcribed into mRNA, what is the corresponding segment of mRNA (before any processing)?

d. 5’-UAC-GUA-CGG-3’

In the coding sequence of DNA below an inserted nucleotide is shown in lower case. If this is the start of an open reading frame, what would be the consequence(s) for the final peptide.ATGAACAATcGCGCCTGAGGTAGCTGAC

 premature termination

What peptide sequence would you expect from the template strand of DNA below? 3’ - AAC CTC TAC GAG CTC ATG - 5’

Leu Glu Met Leu Glu Tyr

In eukaryotes:

Introns are transcribed

What is true about cis-regulatory elements?

they are sometimes present within introns

Gene bodies sometimes overlap because

d. exons and introns can be templated on different strands of DNA

Sequencing of the human genome revealed

b. just over 40,000 genes, similar to what had been predicted theoretically

Which of the following components is required for a successful Polymerase Chain Reaction (PCR)?

c. DNA polymerase

Which of the following statements are true about simple sequence repeat loci?

c. they often have alleles that vary in size

In the context of second generation sequencing, the PCR step is important for:

detecting terminator-linked dyes

For whole genome sequencing, libraries of bacterial artificial chromosomes…

Have largely been repealed by third generation long-read sequencing

Modern genetics and genomic analyses have benefited enormously from technical advances made since the 1970s. Such advances include:

Methods for targeted genome editing

Kary Mullis played an important role in developing PCR, all while taking acid and surfing. He demonstrated that:

d. repeated cycles of template denaturation, primer annealing and strand extension can provide exponential amplification of a DNA template

Since the inception of DNA sequencing, the amount of raw sequence data that can be generated by a sequencing instrument per “run” has increased by:

e. none of the above

“Reversible terminators” are important in what context?

a. Solid phase sequencing

Which of the following statements is true about cyclins and CDKs?

d. cyclins change in abundance across the cell cycle and complexes formed between cyclins and CDKs permit phosphorylation of target proteins

A major role of unphosphorylated Retinoblastoma protein is to:

Sequester the E2F transcription factor, thereby preventing entry into S phase.

Peto’s paradox seems to be explained by

d. the presence of additional tumor suppressor genes in some large-bodied and long-lived species, compared to their presumptive ancestral state

p53 (TP53) induces expression of all of the following EXCEPT:

c. genes promoting the G1-to-S transition

Given your knowledge of p21 function from this class, silencing of its transcription in cancer cells might reasonably be expected to:

c. allow phosphorylation of Rb

Without genomic alterations in tumor suppressor number, life-time cancer risk for an organism would be expected to increase as:

a. lifespan increases

b. cell number increases

d. body size increases

Leading strand DNA replication involves:

b. addition of nucleotides in a 5’-to-3’ direction

e. polymerase alpha activity

In the famous experiments of Meselson and Stahl to identify the mechanism of DNA replication, they found that bacteria grown for a long time in 15N and then transferred for one cycle of replication to 14N contained DNA that sedimented in a single layer after centrifugation. This outcome was consistent with:

1. Semi-conservative replication

2. Dispersive replication

Lagging strand DNA synthesis involves:

a. formation of Okazaki fragments

b. an RNA primer

c. strand synthesis in the 5' to 3' direction

d. activity of DNA ligase

e. a PCNA-dependent "sliding clamp"

Which of the following statements about telomeres is accurate?

a. their length typically decreases within families during each passing generation

b. their DNA sequence allows base pairing within a displacement loop

c. their repeating Leu-Gly codons (TTA-GGG) are binding sites for charged tRNAs

e. they are rejuvenated by synthesis of DNA from an RNA template

Replication in eukaryotic cells involves:

Selection of multiple origins from sites licensed by the PRe-REplciation Complex

The centromere is characterized by:

AT-rich repeated sequence

Roberts syndrome best illustrates the:

e. importance of cohesin stabilization for chromatid pairing during mitosis

Which of the following is NOT likely to be required for chromosome packaging in mitosis?

d. nucleolus

How do histone deactylase (HDAC) enzymes inhibit gene expression?

By removing acetyl groups from specific amino acids in histone tails, increasing the affinity of nucleosomes for DNA

An important pathological role for aberrant histone modification in a pediatric glioma is suggested by:

d. recurrent mutations in histone 3 genes across patients that change lysine-27

What is true of CHiP-Seq experiments?

They require a “reference genome sequence to be available

Which of the following would you expect to be more common in heterochromatin as opposed to euchromatin?

b. H3K27me3

Which of the following might be found in chromatin (pick all that apply):

a. histone 1

b. chromodomain protein 1

c. RNA polymerase II

d. polycomb complex proteins

e. DNA

For the gene model below, choose all the correct identifications.

b. 2: exon coding sequence

c. 3: exon (non-coding sequence)

d. 4: exon (non-coding sequence)