Bio 141 compiled quiz Q&A

The sequence below shows a strand of DNA with a primer. What nucleotide would DNA polymerase add next?

T

For the DNA sequence shown, choose the primer set or sets that could be used to amplify a fragment such that you could determine the number of GGCC repeats that occur within the sequence that is bolded and in blue font. Note that some primer sequences are listed in 3' to 5' orientation.

5'-CAAGTCGGAGTCGATATTA-3' and 5'-CTAGGCCTGCTGATAGTGA-3'

What amino acid would aminoacyl-tRNA synthetase attach to a tRNA with the anticodon 5'-UCU-3'?

Arg

In the graph below, which letter indicates an excitatory postsynaptic potential?

B

You are a researcher at Retriever Pharmaceutical Company. You have been assigned to synthesize polymers that consist of 4 glucose molecules joined by alpha-1,6-glycosidic linkages. What is the molecular formula for the molecule you will produce?

C24H42O21

ATP hydrolysis directly powers the movement of

Na+ out of cells; K+ into the cell

You work for Retriever Pharmaceuticals and are researching drugs that might reduce pain by blocking neuronal signaling in specific neurons. Which of the drugs below should you include in your initial studies?

Natrazine, which blocks voltage-gated sodium channels from opening

Which of the following would move the farthest on a denaturing protein gel?

Ras (25 kDa)

What is the difference between ATP and ADP?

The number of phosphate groups. 3 in ATP and 2 in ADP

Shang et al. determined the protein structure of a coronavirus spike protein interacting with a human receptor protein. Part of the structure of the human protein is shown below. What is the best description for the secondary structure of this protein?

The protein consists entirely of alpha helices.

Part of the insulin signaling pathway is illustrated below. What is happening in step 2 of this illustration?

The receptor is phosphorylating itself.

In a neuron, electrical signals move toward the cell body along

dendrites

An ionic chemical bond is one in which

electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged

What term measures the amount of heat content of a system?

enthalpy

Which group(s) include cells with a nucleus?

eukarya

You are measuring glucose concentrations in the cytoplasm of liver cells. In what form would glucose be in this environment?

exclusively ring form

Examine the signaling pathway in the figure below. How would the molecule marked B be classified?

extracellular signal

What establishes the resting potential in neurons?

flow of potassium ions through leak channels

Ions move through ion channels

from regions of high concentration to regions of low concentration

Which description applies to starch?

glucose monomers linked by alpha-1,4 and alpha-1,6 bonds

Which amino acids have side chains that would likely be found on the interior of a protein where they would be shielded from water?

glycine, leucine, and alanine

Jin is preparing liposomes for a lab experiment. He makes them with a 0.04 M NaCl solution inside the liposomes and places them in a 0.1 M NaCl solution. In this experiment, the solution outside the liposomes is ______________ relative to the solution inside the liposomes.

hypertonic

Condensin complex subunit 1 is a large nuclear protein. Where in a eukaryotic cell would you expect this protein to be synthesized?

in the cytosol

In eukaryotes, where are the enzymes of the electron transport chain located?

in the inner membrane of mitochondria

You are growing a culture of E. coli in the lab, and you accidentally put the culture in a 20oC incubator instead of the regular 37oC incubator. Which of the following types of membrane changes would be the most beneficial to maintain the fluidity of the cell membrane at the new temperature?

increase the fraction of unsaturated fatty acids

You are researching the regulation of the G1 checkpoint and discover an enzyme that transfers phosphate groups from ATP to a cell cycle regulatory protein. What would be the best classification for this new enzyme that you have discovered?

kinase

The figure below shows coupled transcription and translation. What direction will RNA polymerase move?

left to right

GABA is a neurotransmitter that acts in the central nervous system. GABA released into the junction between neurons can bind to a potassium channel and open it. How would you classify this channel?

ligand-gated potassium channel

The list below includes various membrane transport proteins found in neurons. For each type of protein, indicate whether movement of molecules via that protein is active or passive.

ligand-gated sodium channel : passive voltage-gated sodium channel: passive sodium-potassium pump: active voltage-gated calcium channel: passive ligand-gated chloride channel: passive

In noncyclic electron flow during photosynthesis, what is the source of the energy used to excite electrons in photosystem II?

light

Which of the following is a function of the smooth ER?

lipid synthesis

What type of RNA is synthesized during transcription?

mRNA, rRNA, and tRNA

For a neuron at rest with a membrane potential of -65 mV, increasing the movement of potassium ions out of the cell would

make the membrane potential more negative

You are exploring a planet in the Corellian system and studying a diploid species called Drall. You analyze the chromosomes of a Drall somatic cell and find 12 DNA double helices. Each chromosome consists of two double helices held together at the centromere. Which stage(s) of the cell cycle could this cell be in?

metaphase G2 prophase

DNA polymerase catalyzes addition of an incorrect base about once in every 100,000 bases. After DNA polymerase has moved past the incorrect base, a group of enzymes can recognize the error and remove a section of the new DNA, and the region can be synthesized again. This process is called

mismatch repair

Adam is studying a region of a protein that is coded by the first mRNA shown below, in frame beginning at the appropriate end of the sequence. He finds a variant of the gene that codes for the second mRNA shown below. How should he classify this mutation? Normal mRNA: 5'-CAGUCAUGCAGU-3' Variant mRNA: 5'-CAGUCAUACAGU-3'

missense

You have been appointed as the lead scientist in the NIH's Zombie Investigations Division. You begin by reviewing data from previous studies, but the graph of the data has an error. What is the error in the graph below?

missing axis label

Substance X is a small charged molecule. It is found at higher concentration outside the cell than inside the cell. How might substance X enter cells?

movement through an ion channel or facilitated diffusion via a carrier

There is a pond that contains two different kinds of fish-like creatures, one called lumpies and the other called stumpies. All stumpies are genetically identical to each other, but the lumpie population has quite a lot of heritable variation. Lumpies are eaten by a larger kind of aquatic animal called jabberjaws, that sometimes will also eat stumpies. And lumpies and stumpies sometimes eat each other. Which of the following statements about natural selection and lumpies and stumpies is true?

natural selection can act on lumpies, but not on stumpies

Which of the following are properties of the genetic code?

nearly universal redundant conservative

Electronegativity values for various atoms are listed below. H 2.1 B 2.0 C 2.5 N 3.0 O 3.5 P 2.1 S 2.5 A C-H bond would be classified as

nonpolar covalent

Match the phase of the action potential with the primary channel that is open during that phase.

resting: K+ leak channels depolarization: voltage-gated Na+ channels repolarization: voltage-gated K+ channels hyperpolarization: voltage-gated K+ channels

What catalyzes the formation of peptide bonds?

ribosomes

The figure below shows a signaling pathway initiated by epinephrine. What kind of molecule is cyclic AMP in this pathway?

second messenger

The figure below shows a signaling pathway initiated by the hormone marked E in the figure. The hormone binds to its receptor, marked ERalpha/beta in the figure. How could you classify this receptor?

steroid hormone receptor

A peptide bond is formed between

the amino group of one amino acid and the carboxyl group of another amino acid

In a simple synapse, where do neurotransmitters act?

the dendritic membrane

What molecule or reaction supplies the energy for polymerization of nucleotides in the process of DNA replication?

the phosphate bonds in the nucleotide triphosphates that serve as substrates

What molecule or reaction supplies the energy for polymerization of nucleotides in the process of transcription?

the phosphate bonds in the nucleotide triphosphates that serve as substrates

What establishes the electrochemical gradient in neurons?

the sodium-potassium pump

In eukaryotes, CTP is required for RNA synthesis in the nucleus. How would CTP enter the nucleus?

through nuclear pores

The figure below shows a chloroplast. Name the structure marked C.

thylakoid

What is the primary function of the reactions that follow glycolysis in ethanol fermentation?

to regenerate NAD+ from NADH, so glycolysis can continue

What recognizes and binds to promoters in eukaryotic genes?

transcription factors

You have isolated a new species of cells from the polar ice caps, and you want to place this new species in the appropriate branch of the tree of life. You sequence a region of the ribosomal RNA (rRNA) from these cells and compare them to the same regions from bacteria, eukarya, and archaea, shown below. bacteria: AUAGAUGG eukarya: AAAGAAGG archaea: AAUGGAGU The sequence of the new cells is AAUGGAGG. Based on these results, to which branch of the tree of life should you assign this new species?

archaea

The figure below shows a reaction coordinate for the reaction W + X --> Y + Z. Which letter in the figure indicates the activation energy for the catalyzed reaction?

b

Accuracy in the translation of mRNA into the primary structure of a polypeptide depnds on specificity in which of the following?

binding of the anticodon to the codon attachment of amino acids to tRNAs by aminoacyl tRNA synthetases

In the context of DNA, the term antiparallel means

When two DNA strands pair, they run in opposite directions.

You are setting up a DNA gel in the lab, but you didn't write down whether the sample will run toward the positive (red) or negative (black) electrode. Then you remember that you learned about gels in BIOL 141. How should you set up your gel apparatus?

With the sample running toward the positive (red) electrode because the phosphate groups of DNA are negatively charged

What role(s) does DNA polymerase III play in E. coli replication?

adding nucleotides to the 3' end of the leading strand adding nucleotides to the 3' end of the lagging strand

In a study published in the New England Journal of Medicine on April 16, 2020, van Doremalen, et al., describe the aerosol and surface stability of SARS-CoV-2, the virus that causes the novel coronavirus illness. They measured the amount of virus remaining after varying amounts of time. They repeated the experiment on various materials, including copper, cardboard, stainless steel, and plastic. In the experiment described, what is the dependent variable?

amount of virus

A phospholipid molecule that includes two saturated fatty acid chains could be characterized as

amphipathic

In biology, a theory is

an explanation for a broad class of phenomena that is supported by a wide body of evidence

Examine the karyotypes below. The karyotype on the left comes from a non-cancerous cell; the karyotype on the right comes from a cancer cell. What can you directly observe in the cancer cell karyotype?

aneuploidy involving chromosome 7

Which events occur during interphase?

DNA is replicated.

The leading strand is synthesized ______; the lagging strand is synthesized ______.

5'-->3-; 5'-->3'

For the reaction A + B --> C + D, the change in entropy is 867 kJ/(mol*K) and the change in enthalpy is -18,756 kJ/mol. What will delta G be for this reaction at 308 K.

-285792

The items below are steps in neuronal signaling at a synapse. Put them in the correct order.

1. Voltage-gated sodium channels in the presynaptic neuron open, depolarizing the neuron. 2. Voltage-gated calcium channels in the presynaptic neuron open. 3. Neurotransmitter is released into the synaptic cleft. 4. Neurotransmitters bind to ion channels on the postsynaptic neuron. 5. Ligand-gated ion channels in the postsynaptic neuron open, causing a postsynaptic potential.

You are the new head of research and development at the Retriever Drug Discovery Lab. Your predecessor left a note saying that they had identified a peptide that was four amino acids long and had potent activity as an anti-acne drug. There is no other information on the note. How many peptides would you have to synthesize to test all possible peptides of the appropriate length?

160,000

Tay-Sachs disease is caused by mutations in the HEXA gene, which is located on chromosome 15. There are 58 known variants of the HEXA gene. What is the maximum number of different alleles of HEXA that can be present in an individual?

2

Pablo made a buffered solution with [H3O+] of 4 mM. What is the pH of this solution? Note: Your answer must include at least two digits.

2.4

The diploid cells that produce sperm in human males contains 46 chromosomes. If one of these cells undergoes a non-disjunction event in meiosis II, what is the chromosome number in each of the resulting sperm cells?

23, 23, 24, 22

How many carbon atoms must be fixed in the Calvin Cycle to produce 4 molecules of glucose?

24

How many single bonds would a nitrogen atom form to fill its outer electron shell?

3

You discover a new species of archaea. Upon analyzing its DNA, you determine that 18% of the bases are cytosine. What percentage of the bases are adenine?

32

You are exploring the planet Ba'Ku and discover a new organism that you name kelbus. You observe that kelbus has a life cycle different from that of humans. Diploid cells come together in fertilization. The products of fertilization then replicate through mitosis. What would be the ploidy of the resulting cells?

4n

In translation, in what direction is the mRNA read?

5' --> 3'

How many copies of a region of DNA will be produced in 29 rounds of PCR, assuming 100% efficiency?

536,870,912

A diploid organism has 36 chromosomes per cell. How many DNA double helices would be present in each cell during prophase I of meiosis?

72

Based on the figure below, what can you conclude about the cluster of viruses shown in pink and labeled "85% of viruses from Washington State"?

85% of viruses from Washington State share a common ancestor.

What of the following can be observed in the graph below?

9 action potentials, all with the same magnitude and duration

A cell metabolizes 48 molecules of glucose via aerobic respiration. How many molecules of NADH will be produced in pyruvate processing from the breakdown of these molecules of glucose?

96

The figure below shows a gene. The transcribed region is shown in green and marked with a green bar below the double-stranded DNA. RNA polymerase moves left to right when transcribing this gene. Which letter indicates the position of the promoter?

A

In eukaryotes, how does a mature mRNA differ from a primary transcript?

A mature mRNA molecule includes a 5' cap. A mature mRNA molecule includes a poly(A) tail. Introns are removed from the primary transcript in the processing to produce a mature mRNA

Which of the following defects could lead to an increased rate of cell division?

A nonfunctional p53 An Rb protein that cannot bind E2F

In multiple sclerosis, the myelin sheaths in the central nervous system are demyelinated. How does this disease manifest at the level of the action potential?

Action potentials move more slowly along the axon.

The following diagrams show various stages of cell division in different cells of a sexually reproducing, diploid organism. The diagrams are not shown as occurring in sequence. For this problem, assume that all of the cells come from the same organism. Only the plasma membrane is shown. Which of the following statements regarding the dividing cells is correct?

Cell C is in metaphase of meiosis II

The image below shows a section of an axon with three sodium channels, marked A, B, and C. As the action potential propagates along the axon, which of the following might you see when examining these three channels?

Channel A closed Channel B open Channel C in refractory state

The mRNA below codes for part of a protein. The reading frame begins with the first nucleotide at the appropriate end of the molecule. What polypeptide would be synthesized using this mRNA in translation?

Cys-Asn-Ala-Val

What effect would disrupting actin filaments have on M phase in an animal cell?

Cytokinesis would not occur normally.

In the figure below, which letter points to the leading strand?

D

In the graph below, which letter marks the repolarization phase?

E

Which of these cells contains two replicated chromosomes?

I IV

You are working in a lab and have identified a new mutation in a strain of E. coli you are studying. The new mutation introduces a stop codon upstream of the coding sequence for the Retriever gene. Specifically, the mutation changes the six bases immediately before the +1 site from AGTACG to CGTTGA. What effect will this mutation have on gene expression?

It will have little or no effect on gene expression.

The mRNA below codes for part of a protein. The reading frame begins with the first nucleotide at the appropriate end of the molecule. What polypeptide would be synthesized from this region of mRNA in translation? 5'-AUCCGGUGCAAUGCAUAACGU-3'

Ile-Arg-Cys-Asn-Ala

You want to test the hypothesis that covering a person in mashed dandelion greens repels mosquitoes. Which of the following should you do when designing your experiment?

Include controls to check for factors other than the presence or absence of mashed dandelion greens that might influence the results. Keep experimental conditions as constant as possible. Repeat the experiment.

Which of the following are net outputs of the light dependent reactions of photosynthesis, AND ALSO net inputs of the Calvin cycle reactions?

NADPH, ATP

Some sexually reproducing species can self-fertilize. Will self-fertilization produce offspring genetically identical to the parent?

No, because genetic recombination occurs in meiosis.

Three adult children (Kia, Skip, and Lian) whose mother is no longer living, become suspicious that the man they grew up with as their father, Kirby, might not be the biological father of one or more of them. They obtain the STR data for the 8 loci shown in the STR table. The numbers indicate the alleles (numbers of repeats) each individual has for that STR locus. Based on this data, which of the children can Kirby NOT be the biological father of?

Skip

How does the sugar in DNA differ from the sugar in RNA?

The sugar in DNA is lacking an oxygen at the 2' carbon.

SDF2 is an ER protein involved in protein quality control. What binds directly to the ER signal sequence?

a signal recognition particle

Which of the following would be affected if actin function were disrupted?

cell crawling and cytokinesis

Which of the following is required for an animal cell to pass the M-phase checkpoint?

chromosome attachment to spindle fibers

Which of the following would be found in ALL prokaryotic and eukaryotic cells?

chromosomes RNA ribosomes

Which steps in cellular respiration are subject to feedback inhibition by high concentrations of NADH?

citric acid cycle

Wild lilac extract and wild ginger extract inhibit the enzyme Halflight. A component in wild ginger extract binds to the Halflight active site, and a component in wild lilac extract binds to a regulatory site away from the active site. How would you characterize the component in wild ginger extract?

competitive inhibitor

What type of bonds are formed by ligase?

covalent

What functional group is present at the 5' end of a nucleotide?

phosphate

Of the three general types of lipids described in this course, which form bilayers? Note: Spelling counts.

phospholipids

What serves as the ground substance in the extracellular matrix in humans?

proteoglycans

If you use radioactive carbon to label the carbons in glucose, where would you find radioactive carbon atoms at the end of glycolysis?

pyruvate

When elemental sodium reacts with elemental chlorine, the atoms ionize spontaneously. Uncharged Na becomes Na+, and uncharged Cl becomes Cl-. The means that the Cl atoms have been

reduced