Deck 5: Genetics

Question 1

Where can the DNA of prokaryotic cells be found?

A) nucleus
B) nucleoid
C) around histones
D) nucleolus
E) in numerous linear chromosomes

Answer 1

nucleoid

Question 2

The genetic code

A) uses a quartet code to encode the codons.
B) contains sense codons and nonsense codons.
C) encodes for 18 amino acids.
D) relies on codons made up of DNA.
E) has 60 codons.

Answer 2

contains sense codons and nonsense codons.

Question 3

Which of the following statements about the primosome is false?

A) The primosome includes primase to lay down RNA primers that will jump- start replication.
B) The primosome is responsible for starting DNA replication.
C) The primosome is recruited to the origin of replication.
D) The primosome includes RNA polymerase to build the protein.
E) The primosome includes helicase to unwind the DNA.

Answer 3

The primosome includes RNA polymerase to build the protein.

Question 4

Helicase

A) creates the replication fork.
B) allows for DNA polymerase III to bind to the DNA.
C) causes a bubble of single- stranded DNA to form.
D) relieves coiling tension that develops as the helix is unwound.
E) unwinds the DNA.

Question 5

RNA carries a genetic message in triplet code (codons) and is translated to build a protein.

A) Transfer
B) Alternative
C) Junk
D) Messenger
E) Ribosomal

Question 6

Which of the following statements about post- translational modifications is false?

A) Post- translational modifications provide a way for cells to regulate gene product functionality.
B) Post- translational modifications can include the addition of extra amino acids.
C) Post- translational modifications are often required for a protein to function.
D) Additional organic factors could be added.
E) Additional inorganic factors could be added.

Question 7

As replication proceeds in a prokaryotic cell, how many replication forks exist on one chromosome?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 8

RNA differs from DNA in all of the following ways except

A) RNA has directionality.
B) in RNA, uracil (U) replaces thymine (T).
C) RNA is single stranded.
D) RNA has a hydroxyl group on the 2' carbon.
E) there are several different types of RNA including mRNA, tRNA, and rRNA.

Question 9

Which of the following statements about the lagging strand is false?

A) It synthesizes many RNA primers.
B) It is where one would find Okazaki fragments.
C) It is a discontinuous process.
D) It uses only one molecule of DNA polymerase I.
E) It builds in the opposite direction of the helix unwinding.

Question 10

Which of the following terms refers to the genetic makeup of an organism?

A) primosome
B) purine
C) genotype
D) heritable
E) phenotype

Question 11

Introns

A) are sometimes left in the mRNA sequence for alternative splicing.
B) are removed from mRNA in the cytoplasm.
C) are removed by a complex called the spliceosome.
D) are considered to simply be junk DNA.
E) are only found in eukaryotes.

Question 12

The primary flow of genetic information in cells is from

A) DNA - protein - RNA.
B) protein - RNA - DNA.
C) RNA- DNA - protein.
D) DNA - RNA - protein.
E) protein - DNA- RNA.

Question 13

Which direction are phosphodiester bonds of DNA usually built in?

A) 3' -5'
B) 5' -1'
C) 1' -5'
D) 5' -3'
E) Any direction is fine and will not affect the function of the DNA strand.

Question 14

Which of the following statements about reverse transcription is false?

A) Reverse transcription is performed by certain viruses and human cells.
B) Reverse transcription builds copy DNA (cDNA).
C) Reverse transcription uses RNA as a template.
D) Reverse transcription requires a particular initiation sequence.
E) Reverse transcription uses special enzymes called reverse transcriptase.

Question 15

DNA replication is

A) the process a cell uses to make protein.
B) going to result in relatively few mutations.
C) the exact same for prokaryotes and eukaryotes.
D) error prone.
E) slow.

Question 16

Which of the following nitrogen bases is found only in RNA and NOT in DNA?

A) cytosine
B) adenine
C) guanine
D) uracil
E) thymine

Question 17

Eukaryotic replication differs from prokaryotic replication, because eukaryotic replication

A) involves only one circular chromosome.
B) involves more protein factors.
C) has multiple replication initiation sites.
D) takes longer to copy.
E) has more DNA to copy.

Question 18

Which of the following statements about transcription in prokaryotes in false?

A) It uses a lot of cellular energy.
B) It uses RNA polymerase as the main enzyme.
C) It occurs in the nucleus.
D) It is tightly regulated by the cell.
E) It uses DNA as the template to make RNA.

Question 19

Which of the following statements about protein synthesis is false?

A) Protein synthesis can be disrupted by many antibiotics.
B) Protein synthesis is responsible for most physical and functional cell features.
C) Protein synthesis is where genetic information is read and used to create gene products.
D) Protein synthesis is central to life.
E) Protein synthesis has two main stages: replication and transcription.

Question 20

Which of the following statements is false?

A) Nonstandard amino acids are found in prokaryotes and eukaryotes.
B) There are hundreds of amino acids found in nature.
C) There are 22 amino acids that are genetically encoded by codons.
D) In some species, one stop codon has been swapped out for one of the nonstandard amino acids.
E) Four amino acids are considered nonstandard.

Question 21

Which of the following statements is true about epigenetic regulation?

A) Epigenetic regulation is completely understood.
B) Epigenetic regulation is a way to control protein synthesis.
C) DNA methylation is one example of epigenetic regulation that is only found in prokaryotes.
D) Epigenetic regulation is unable to affect a cell's phenotype.
E) Epigenetic regulation changes the sequence of DNA nucleotides.

Question 22

Which of the following statements about plasmids is false?

A) Molecular biologists often use plasmids to generate cell lines that make useful products for medical applications.
B) Plasmids are commonly shared among cells by horizontal gene transfer mechanisms.
C) Plasmids are nonchromosomal DNA segments found in bacteria and a number of eukaryotic cells.
D) If present, plasmids are always essential to cell survival.
E) Plasmids are easily manipulated in the laboratory.

Question 23

How does transformation differ from conjugation?

A) Transformation requires only fresh DNA be used.
B) Transformation involves a pilus.
C) Transformation can only exchange DNA between bacteria of the same species.
D) Transformation requires DNA to be on a plasmid.
E) Transformation takes up DNA from the environment.

Question 24

A mutation does not change the amino acid sequence of a protein.

A) nonsense
B) silent
C) missense
D) frameshift
E) deletion

Question 25

All of the following are examples of post- transcriptional regulation except

A) cells can regulate how mRNA is spliced and exported out of the nucleus before translation occurs.
B) in prokaryotic cells, small noncoding RNAs that work in post- transcriptional regulation include small RNAs.
C) cells can regulate translation by methylating certain DNA nucleotides.
D) cells can regulate translation by affecting how readily ribosomes associate with mRNA to read it.
E) in eukaryotic cells, small noncoding RNAs that work in post- transcriptional regulation include microRNAs and short interfering RNAs.

Question 26

Naturally occurring mutations are often referred to as mutations.

A) unnoticed
B) deleterious
C) spontaneous
D) neutral
E) insertion

Question 27

Which of the following statements is false about quorum sensing?

A) Quorum sensing allows bacteria to alter their protein synthesis in response to changes in population density.
B) Coordinated protein synthesis through quorum sensing is the foundation for forming biofilms.
C) Quorum sensing allows unicellular organisms to coordinate their processes.
D) Bacteria can communicate using chemical messengers called autoinducers.
E) Bacteria that experience quorum sensing have a decreased chance of survival.

Question 28

is when the fertility plasmid merges with the bacterial cell's chromosome and ceases to be an independent plasmid in the cytoplasm.

A) Conjugation
B) Recombination
C) Transformation
D) Transduction
E) Transfection

Question 29

Which of the following statements about constitutive genes is false?

A) Constitutive genes produce their proteins when a cell encounters a specific environmental change.
B) Constitutive genes are expressed at any given time.
C) Constitutive genes function differently than facultative genes.
D) Constitutive genes are referred to as housekeeping genes.
E) Constitutive genes account for less than 20 percent of a cell's genes.

Question 30

Which of the following statements about conjugation is false?

A) In conjugation a bacterium carries a fertility plasmid.
B) In conjugation a bacterium forms a small hollow tube called a pilus.
C) Conjugation can be a problem because fertility plasmids often carry genes that endow cells with drug resistance or the ability to produce toxins.
D) In conjugation a bacterium attaches to a neighboring bacterial cell that lacks a fertility plasmid.
E) Conjugation is sexual reproduction for bacteria.

Question 31

Which of the following terms is correctly matched with its description?

A) Deletion mutations: Occur when one or more amino acids are removed from a protein sequence.
B) Insertion mutations: Occur when a cell adds one or more nucleotides to its genome sequence.
C) Point mutations: Occur when an incorrect carbohydrate is added.
D) Substitution mutations: Occur when an incorrect fatty acid is added.
E) Substitution mutations: Occur when an incorrect amino acid is added.

Question 32

Which of the following statements about an inducible operon is false?

A) When off, RNA polymerase is blocked by the operator.
B) When present, an inducer will inactivate the repressor.
C) When off, the repressor binds to the operator.
D) It is off by default.
E) Certain conditions activate transcription.

Question 33

Which of the following statements about pre- transcriptional regulation is false?

A) It allows organisms to rapidly respond to frequent and dramatic changes in the environment.
B) It is managed by transcription factors.
C) It helps cells control when transcription occurs.
D) It helps cells control how often transcription occurs.
E) It is the one way cells can manage to control protein synthesis.

Question 34

Which of the following statements about thymine dimers is false?

A) They are repaired by excision repair.
B) They are repaired by one enzyme that can clip out, lay down new nucleotides, and seal the gap.
C) Patients with xeroderma pigmentosum have faulty DNA repair mechanisms.
D) If resulting mutations accumulate, it can result in cancers.
E) They can be produced by exposure to UV light.

Question 35

Key mechanisms of horizontal gene transfer include all of the following except

A) transposons.
B) conjugation.
C) transduction.
D) transformation.
E) reproduction.

Question 36

In the Ames test, what happens when his- bacteria are exposed to a chemical and experience a higher level of growth than the control?

A) A reversion mutation allowed the his- bacteria to regain their ability to make histidine (revert to his+).
B) The his- bacteria now utilized histidine from the media.
C) The reversion rate is lower than seen for spontaneous mutations.
D) The tested chemical is regarded as a non- mutagen.
E) The his- bacteria utilized DNA repair tools to fix the mutation.

Question 37

Frameshift mutations can do all of the following except

A) insert or delete a DNA base.
B) insert or eliminate an amino acid.
C) change the protein's amino acid sequence.
D) substitute one amino acid for another.
E) render the protein useless to the cell.

Question 38

mutagens are agents that can introduce genetic change through recombination.

A) Frameshift
B) Physical
C) Chemical
D) Organic
E) Biological

Question 39

Which of the following statements is true about specialized transduction?

A) Specialized transduction always directs the production of new phage particles immediately upon infecting the host bacterium.
B) Bacteriophage undergoing specialized transduction integrate their DNA into a random region of the host cell's genome.
C) Specialized transduction requires that bacteriophage infect at least two different cells to be carried out.
D) A bacteriophage may at some point become reactivated, excise itself and surrounding bacterial genes from the genome, and begin to build new phage particles.
E) Specialized transduction occurs in all bacteriophage except the temperate phages.

Question 40

Which of the following statements about mutations is false?

A) Mutations are essential to variation within species.
B) A mutation is a change in the genetic material of a cell or virus.
C) Mutations are essential to evolution within species.
D) Multicellular organisms evolve faster than unicellular organisms.
E) A mutation in a single- celled organism is more likely to be passed to daughter cells than a multicellular organism.

Question 41

Explain how a bacterium living in a biofilm behaves very similar to a primitive multicellular organism.

Question 42

Using the central dogma of molecular biology, explain how an organism's genotype influences its phenotype.

Question 43

Many mutagens cause a rate of mutation that promotes the development of cancers; such mutagens are called carcinogens.

Question 44

Both prokaryotes and eukaryotes have several types of pre and post- transcriptional regulation. What advantage does pre- transcriptional regulation have over post- transcriptional regulation and vice versa? Name three examples of each type of regulation.

Question 45

Gyrase breaks the hydrogen bonds between DNA strands and unwinds the DNA strands while topoisomerases relieve the coiling tension that develops as the helix unwinds.

Question 46

Introns shouldn't be perceived as junk or a nuisance, rather, they provide an opportunity for genetic diversity.

Question 47

Describe the four scenarios of Griffith's experiment in the 1920s and summarize the main conclusion.

Question 48

A sequence of cDNA would contain introns but no exons.

Question 49

A repressible operon produces a repressor that is inactive from the start.

Question 50

DNA replication is a semiconservative process.

Question 51

Which of the following is true about retrotransposons?

A) Retrotransposons rely on an RNA intermediate to insert into a new part of the genome.
B) Retrotransposons do not require an RNA intermediate.
C) Retrotransposons can use a "cut- and- paste" strategy.
D) Retrotransposons never remain in their original location.
E) Retrotransposons can use a "copy- and- paste" strategy.

Question 52

A reversion mutation is when a base- substitution mutation is changed back to the original DNA sequence.

Question 53

An organism's genotype influences its phenotype.

Question 54

What are the differences between DNA replication on the leading and lagging strands and why do they exist?

Question 55

DNA transposons rely on the enzyme reverse transcriptase to insert a copy of cDNA into a new location in the genome.