Exam 1 Review
Supplemental Instruction
IowaStateUniversity / Leader: / Matt C.
Course: / Biol/Gen 313
Instructor: / Dr. Rodermel
Date: / 01/29/2017

Introduction: The chapters to be covered by this exam are 1, 2,8, and9.

The exam is going to be a mixture of multiple choice and short answer, but these questions are tough enough that multiple choice will be a sufficient challenge. Work through my worksheets or problems out of the book for more short answer practice.

Multiple Choice

  1. Arabidopsis thaliana is a commonly-used model organism for C3 plants. It is widely used for all of the following reasons EXCEPT for that:
  2. It grows quickly in the lab.
  3. It is inexpensive to grow.
  4. It produces a specific, limited number of offspring.
  5. Its genome is small.
  6. All of these are reasons why A. thaliana is a model system.
  1. What historically-held theory was disproven by August Weismann’s experiment?
  2. Gemmule theory.
  3. The theory of blending inheritance.
  4. The theory of spontaneous generation.
  5. Pangenesis.
  6. Multiple of the above.
  1. Heterozygous inheritance of one copy of the sickle-cell hemoglobin gene helps to confer greater resistance to malaria. Research groups interested in this phenomenon track the number of heterozygous individuals in different parts of Africa as related to malaria infection rates. What type of genetic research would this be considered?
  2. Evolutionary genetics.
  3. Population genetics.
  4. Molecular genetics.
  5. Transmission genetics.
  6. None of the above answers.
  1. Which of these describes the primary structure of DNA?
  2. A nucleotide triphosphate.
  3. The α-helix.
  4. Wrapping of the DNA around histones.
  5. Condensation of the chromatid.
  6. None of the above.
  1. Below is the nitrogenous base adenine. Which of the following nitrogenous bases will hydrogen bond with adenine in double-stranded DNA?


  1. What is the method by which new DNA is taken up and incorporated into the genome.

  1. Transposition.
  2. Translation.
  3. Induction.
  4. Transformation.
  5. None of the above.

  1. Avery, MacLeod, and McCarty expanded on Griffith’s work and demonstrated that DNA was the molecule used by bacteria to pass information on. What would their result have been if protein was the hereditary material?
  1. Only the samples treated with DNase and RNase would cause transformation.
  2. Only the samples treated with protease and DNase would cause transformation.
  3. Only the samples treated with protease and RNase would cause transformation.
  4. Only samples treated with protease would cause transformation.
  5. None of the above would be the case.
  1. If topoisomerase causes positive supercoiling, what is it happening?
  1. The DNA is binding more tightly to the histones.
  2. The protein is being chaperoned into the necessary confirmation.
  3. It is decreasing the base pairs per turn.
  4. It is stabilizing one of the telomeres.
  5. None of the above.
  1. You come across an unknown nucleic acid and measure the proportion of uracil to be 27% of the total nitrogenous bases and the proportion of cytosine to be 25%. What is the most likely conclusion you can come to about the nucleic acid?
  1. The molecule is DNA with [A]=27% and [G]=25%.
  2. The molecule is RNA with [A]=27% and [G]=25%.
  3. The molecule is single-stranded DNA.
  4. The molecule is single-stranded RNA.
  5. You do not have enough information.
  1. What would the conclusion of the Meselson-Stahl experiment have been if there was only ever one band in their CsCl-gradient centrifuge tube?
  2. DNA replication is conservative.
  3. DNA replication is dispersive.
  4. That A, T, C, and G bind indiscriminately.
  5. That the Tetranucleotide Theory is possibly true.
  6. Nothing. It would indicate that the experiment has a systematic error.
  1. Which of the following single-stranded RNA sequences will form a hairpin structure?
  2. -AGAGACCCCCCCAGAGA-
  3. -AGAGACCCCCCCTCTCT-
  4. -AAAAAGGGGGGAAAAA-
  5. -AGAGAGGGGGGCUCUC-
  6. RNA doesn’t form secondary structures like hairpins.
  1. Which of the following is known to be TRUE about centromeres?
  2. Centromeric sequences help prevent chromosome shortening in eukaryotes.
  3. Centromeric sequences are added just prior to metaphase I so that spindle microtubules may attach to the chromosome.
  4. Centromeres have a specific consensus sequence that is identified during cellular replication and to which the kinetochore binds.
  5. Centromeres are made up of primarily euchromatin.
  6. None of the above are true.
  1. Which experimenter disproved the classical theory of blending inheritance?

  1. Gregor Mendel
  2. Franklin Stahl
  3. Rosalind Franklin
  4. Hugo de Vries
  5. August Weismann

  1. A certain molecule of chromatin is found to contain 10 molecules of histone H1. How many molecules of histone H4 would you expect there to be in this sample?
  2. 5
  3. 10
  4. 15
  5. 20
  6. None of the above would be expected.
  1. Which of the following is NOT a common model organism?
  2. C. elegans – Nematode
  3. M. musculus – Mouse
  4. A.thaliana – Thale Cress
  5. D.rerio – Zebrafish
  6. All of these are common model organisms.
  1. Which of these describes outcrossing?
  2. Promoting mating between different species.
  3. Removing certain alleles via selective crossing.
  4. Increasing genetic diversity by breeding individuals from two lineages.
  5. Performing genetic modification to artificially alter an offspring’s genome outside of conventional mating.
  6. None of the above.
  1. Pick the true statement out of the following related to chromosome packing.
  2. Packing is static to maintain heterochromatin in a condensed state.
  3. Higher-order packing is the simplest to model since the chromatin fibers are so much larger than primary or secondary structure.
  4. Chromosomes are only packed during and just before the start of M-phase.
  5. During growth phase, all genes are unpacked enough to be easily transcribed.
  6. None of the above is true.
  1. Which element of the Central Dogma can be run in reverse?
  2. Transcription; make DNA from RNA.
  3. Translation; make RNA from protein.
  4. Natural selection; select for a previously-disadvantageous trait.
  5. Evolution; reduction of complexity via natural selection.
  6. None of the above.
  1. Do to years of agricultural manipulation, bread wheat is stably hexaploid. What is its haploid number?
  2. 1
  3. 2
  4. 3
  5. 6
  6. Multiple of the above are possible.
  1. Which researcher demonstrated that genetic variation can arise randomly, supporting Darwin’s theory of evolution by natural selection?
  2. Phoebus Levene
  3. Hugo de Vries
  4. Friedrich Miescher
  5. Gregor Mendel
  6. William Bateson
  1. You identify a cellular organism with a cell wall, a single flagellum, a large, membrane-bound organelle, and no true nucleus. However, it has linear DNA. What kind of organism is this?

  1. A eukaryote.
  2. A prokaryote.
  3. A protist.
  4. A complex virus.
  5. None of the above.

  1. What type of interaction holds two DNA strands together in a helix?
  2. Hydrogen bonding.
  3. Covalent bonding.
  4. Ionic bonding.
  5. Van der Waals interactions.
  6. None of the above.
  1. It is believed that albinism increased in Hopi American Indian groups as a result of what?
  2. A reproductive advantage conferred to albino individuals.
  3. The development of a dominant form of albinism.
  4. Epigenetic effects that spread through the population.
  5. Random genetic drift due to small, isolated subpopulations.
  6. Albinism actually occurred at a lower rate among Hopi individuals.
  1. Over a segment of dsDNA, there are 36 nucleotides between the two strands. Two turns are completed by the molecule. Which of the following is true?
  2. There are 18 base pairs per turn.
  3. It is under-rotated.
  4. It is positively supercoiled.
  5. The DNA must be breathing.
  6. Multiple of the above.
  1. One modification that can be done to histone proteins is to add a phosphate group to one of the uncharged amino acids on its histone tail. Which of the following might occur as a result?
  2. DNA binds more tightly, promoting condensation.
  3. DNA binds less tightly, promoting condensation.
  4. DNA binds more tightly, promoting decondensation.
  5. DNA binds less tightly, promoting decondensation.
  6. This would not affect DNA binding.
  1. Which of the following is true about cellular replication?
  2. Bacteria have one origin of replication while eukaryotes have several; one on each chromosome.
  3. A pair of sister chromatids is considered a homologous pair.
  4. A bacterium’s circular chromosome must be broken at the end of a replication cycle.
  5. Daughter cells become haploid and develop back to diploidy before splitting again.
  6. In eukaryotes, the nucleus pinches off to form two nuclei prior to the entire cell splitting during cytokinesis.
  1. Which of these forms of DNA is a left-handed helix?
  2. A-DNA
  3. B-DNA
  4. C-DNA
  5. Z-DNA
  6. None of these.
  1. Which of the following genetic conditions could be identified with a karyotype?
  2. Red-green color-blindness: a recessive allele on the X-chromosome.
  3. Turner syndrome: having only a single X chromosome.
  4. Huntington’s disease: an autosomal dominant trait.
  5. Leigh syndrome: mutations in mitochondrial DNA.
  6. None of the above.
  1. An identical 224 bp sequence is observed at several different points along chromosome 3 in humans. What type of sequence would this be?
  2. Unique-sequence DNA.
  3. Tandem repeat sequences.
  4. Intersperse repeat sequences.
  5. Dispersed repeat sequences.
  6. Highly repetitive sequences.
  1. A bacterium engages in what form of replication?
  2. Asexual replication.
  3. Binary replication.
  4. Theta replication.
  5. Unique-origin replication.
  6. None of the above. Bacterial replication is just like a eukaryote’s.
  1. At which number is the amine (– NH2) bound?
  2. 2
  3. 4
  4. 6
  5. 8
  6. None of the above.
  1. Approximately how much DNA is bound strictly by the core histone octamer?
  2. 145 bp.
  3. 165 bp.
  4. 185 bp.
  5. 205 bp.
  6. None of the above.
  1. A research group investigates the mechanism that produces a recessive phenotype in C. elegans. What type of genetic research is this an example of?
  2. Evolutionary genetics.
  3. Population genetics.
  4. Molecular genetics.
  5. Transmission genetics.
  6. None of the above answers.
  1. Edwin Chargaff proposed the pattern for base pairing using his experimental results on the concentrations of each nitrogenous base in a double-stranded DNA sample. If base pairing instead occurred between A and C or G and T, what would his results be?
  2. [A]=[G]
  3. [C]=[G]
  4. [A]+[T]=[C]+[G]
  5. [T]=[C]
  6. None of the above.
  1. Below is a ribose sugar with numerically-labelled carbon atoms. To which carbon would the phosphate be attached in a nucleotide?

  1. Carbon 1
  2. Carbon 2
  3. Carbon 3
  4. Carbon 4
  5. Carbon 5

  1. Why does acetylation weaken histone binding to DNA strands?
  2. Acetylation removes positive charges that interact with DNA.
  3. Acetylation removes negative charges that interact with DNA.
  4. Acetylation changes the preferred interactions between histone proteins.
  5. Acetylation allows the histone H1 protein to clamp onto the nucleosome complex.
  6. None of the above.
  1. For a certain gene, the sequence of one DNA strand is 5’-ATTGACCTG-3’. What is the sequence of the complement?
  2. 5’-CAGGTCAAT-3’
  3. 5’-ATTGACCTG-3’
  4. 5’-TAACTGGAC-3’
  5. 5’-GTCCAGTTA-3’
  6. You cannot know from this information.
  1. Which of the following sequences would you expect to disassociate from its complement at the lowest temperature?
  2. -AATGCAT-
  3. -ATTGCGT-
  4. -GGCATGC-
  5. -GCCATAC-
  6. Not enough information is provided.