MIC205 Exam 1 (modules 1,2,3)

The following structure represents the cell wall of which type of bacteria?

Gram positive

Bacteria increase numbers by a process called ---------------- (2 words)

binary fission

The appendage that allows bacteria to attach to surfaces is called [---------------].

fimbriae

Doubling of bacterial cells is happening in [------------] phase of the bacterial growth curve

log/exponential

The cell wall is a structure that protects the bacterial cell from lysis.

True

The genetic hereditary material (DNA) in eukaryotes is packaged into linear chromosomes that are located in the nucleus, while the prokaryotes have a single, circular, DNA found in the cytoplasm.

True

The following structure represents the cell wall of which type of bacteria?

Gram negative

You are preparing a sandwich at 6:30 AM to take to school with you. You accidentally cough and introduce 10 bacteria into your sandwich as you are making it. Calculate the number of bacteria that will be present when you eat your sandwich at 10:30 am? The sandwich was lying in your locker throughout this time. The generation time (time taken to double the number of cells) of the bacteria is 30 minutes at room temperature. You may use the following chart to help you visualize the problem.

2560

During replication, which of the following is the correct sequence of the daughter DNA strand that is synthesized using 5" CAGTTCGGA 3" as a template?

3" GTCAAGCCT 5"

During transcription, which of the following will be the correct sequence of the RNA strand that is synthesized using 5" CAGTTCGA 3" as a template?

3" GUCAAGCU 5"

Which of the following could be synthesized using the following template? 3" CAGTTCGGA 5"

5" GTCAAGCCT 3"

Which of the following organisms best represent Box 1 in the picture shown below?

Bacteria

According to the endosymbiont theory:

Bacteria are the ancestors of chloroplasts and mitochondria

-------------, -------------, & --------------- are the three domains of life.

Bacteria, archaea, & eukarya

You have discovered a unique organism in the ocean with the following features: It has a cellular structure with circular DNA as its genetic material. The DNA is dispersed in the cytoplasm, but no organelles can be detected within the cell. The entire cell is covered by a cell wall. This organism is most likely a:

Bacterial cell

Viruses have a cellular structure while bacteria are not cellular.

False

The part labeled D helps with motility of the bacterial cell. Identify D .

Flagella

You have discovered an organism that is 0.7 mm in size from a pond. It contains a nucleus. Which of the following conclusions can you make about this organism?

It cannot be classified as a prokaryote (has nucleus)

According to a study published in 2013, prolonged use of antibiotics may lead to disruption of mitochondrial function. Which of the following BEST explains this observation?

Mitochondria are structurally similar to bacteria; therefore, they are susceptible to antibiotics that target bacteria.

[--------------------] is an electron carrier in the cell.

NADH

Which of the following factors influence bacterial growth?

Oxygen Temperature Nutrient availability

Match the following processes shown on the left column with their correct definition or description on the right column

Transcription: synthesis of an RNA molecule from a DNA template Translation: Process by which mRNA is decoded and a protein is produced Replication: Copying process by which a cell duplicates its DNA Mutations: Random errors in gene replication that lead to a change in the sequence of nucleotides. The source of all genetic diversity.

ALL living cells are classified as either Prokaryotes or Eukaryotes.

True

Bacteria were the earliest organisms to produce oxygen on earth.

True

You have discovered a new microorganism that can potentially eradicate a pandemic infection. Based on the following features that you have discovered, what conclusions can you make about this microorganism? 1. It does not have a cellular structure 2. It cannot exist independently 3. It can be visualized only by an electron microscope 4. It has DNA as its genomic material 5. It does not have a nucleus

Virus

In the following picture, letters X and Y most likely represent

Virus and animal cell, respectively

___________ is the basic unit of a protein (in other words proteins are made from these basic units)

amino acid

Why do bacterial cells regulate gene expression

in response to a changing environment

Which of the following is a change in the sequence of DNA that leads to formation of a stop codon?

nonsense mutation

Which of the following mutation in a DNA sequence will lead to the formation of a stop codon?

nonsense mutation

During fermentation, electrons are transferred from an organic donor compound to

other organic compounds

Which of the following terminologies describe genetic changes that can occur in a bacterial population

transcription

A bacteria has shared antibiotic resistance genes from another bacterium in the environment via plasmids. This is an example of HGT horizontal gene transfer

true

A sequence of 3 nucleotides in the DNA codes for an amino acid

true

Which of the following is true about Eukaryotes? 1. Larger in size than prokaryotes 2. Have internal membranes 3. Contain a nucleus 4. Lack cellular organization

1,2,3

Which of the following can be associated with Archaea? 1. Have a cellular Structure 2. Can be found in extreme environments 3. Lack internal membranes 4. Small in size 5. Classified as prokaryotes

1,2,3,4,& 5

Which of the following can be classified as cellular organisms? 1. Bacteria 2. Viruses 3. Archaea 4. Fungi 5. Prions

1,3,& 4

identify the specific components that make up DNA

A = BASE B = PHOSPHATE C = SUGAR

Which of the following sentences about viruses are correct? A. Viruses are made of DNA or RNA, and proteins B. Viruses are cellular. C. Viruses need host cells for reproduction and survival. D. Viruses contain metabolic pathways E. Viruses can make their own proteins. F. Some viruses may have a lipid envelope

A, C & F

In a cell, the molecule that stores energy to do useful work is -------------

ATP

[------------] , [------------------] and [--------------------] are formed at the end of glycolysis pathway.

ATP, Pyruvate and NADH

Which of the following is NOT a feature of a eukaryotic organism?

Absence of membrane bound organelles

Which of the following best represent organisms with a "Nucleus" in the picture below? Choose all for full credit.

Algae, Fungi

In glucose molecule, high energy electrons are stored within which of the following?

C-H bonds

According to the Central Dogma, which of the following statements represent the flow of genetic information in cells?

DNA to RNA to protein

Listed below in the left column are different structures found in the bacterial cell. Match these bacterial cell structures with their correct function shown in the right column. Each answer may be used one time only.

Endospore: enhances survival in unfavorable conditions Capsule: protects the cell against drying Flagella: responsible for cellular motility or movement Fimbriae: responsible for attachment of cells to surfaces Cell Wall: protects against lysis

Bacteria make structures called --------- to tide over unfavorable conditions in their environment .

Endospores

All viruses contain DNA as the genetic material

False

An antibiotic targeting the the nuclear membrane would be an effective treatment for bacterial infections.

False

It is possible to treat a virus infection with an agent that targets the protein synthesis machinery to inhibit the synthesis of proteins.

False

It would be unsafe to administer an antibiotic that inhibits peptidoglycan synthesis, because this could damage the eukaryotic cell wall in addition to damaging the bacterial cell wall.

False

Only single-celled organisms represent the domain Eukarya.

False

Following terms on the left are associated with protein synthesis and gene regulation. Match these items with their correct definitions on the right. Each answer must be used one time only.

Gene: sequence of bases/DNA that codes for a protein and thus determines a trait Codon: a sequence of three bases/nucleotides that together form a unit of genetic code in a DNA or RNA molecule. Activator: A protein that binds to DNA and stimulates transcription of a specific gene. Repressor: A protein that binds to an operator and physically blocks RNA polymerase from binding to a promoter site

The time taken for one bacterial cell to divide into two cells is called-----------

Generation time

Which of the following is an example of a silent mutation?

Mutation in the DNA that replaces an amino acid with the same amino acid

The following picture depicts sizes in the microbial world. Based on this picture, arrange the following in order from largest to smallest: Bacteria cell, Nerve cell, Chickenpox virus, Sulfur atom, Water molecule

Nerve cell, Bacterial cell, Chickenpox virus, Water molecule, Sulfur atom

Prions is classified under which of the following categories?

Non-living

The bacterial cell wall is made up of which of the following UNIQUE component?

Peptidoglycan

Which of the following is true for a plasmid?

Plasmids are small, circular pieces of double stranded DNA found in bacteria

The binomial system assigns a 2-part name to organisms. In accordance with Binomial nomenclature, what does the underlined part of the name denote in the following example? Escherichia coli

Species

Which of the following is true about horizontal gene transfer?

The transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and perhaps fusions of different organisms. A process in which an organism incorporates genetic material from another organism without being the offspring of that organism transfer of genes between cells of the same generation

Which of the following is a feature of Archaea?

They can live in extreme environments

In the DNA molecule, adenine (A) pairs with

Thymine (T)

A patient with an ear infection was administered an antibiotic that targets the peptidoglycan layer. The causative agent of the infection is a ------------.

bacteria

Prokaryotes consist of two groups of organisms --------------- & -------------- .

bacteria & archaea

In nature, bacteria grow in communities that are encased in a protective gelatinous covering. Such bacterial communities are called -----------

biofilm

Botulism or food poisoning is caused by Clostridium species. It is difficult to eliminate this bacteria from contaminated food because of formation of ----------.

endospores

Fermentation produces more ATP than Aerobic respiration.

false

The energy generated in anabolic reactions are used up in catabolic reactions,

false

The following picture shows how bacteria grow in numbers through the process of binary fission

false

The genetic code converts the sequence of the amino acids into the sequence of nucleotides

false

Which of the following mutations in a DNA sequence will lead to a change in the reading frame of the DNA sequence?

insertion

In --------- phase of the growth curve, there is no change in the number of bacteria. Pick all of the correct answers for complete credit.

lag stationary

The following picture depicts the series of events that led to the evolution of the modern eukaryotic cell. The engulfment of the aerobic bacterium by the ancestral cell led to the evolution of __________, while the engulfment of the photosynthetic bacterium led to the evolution of ________________

mitochondria, chloroplasts

__________ & _____________ are the two types of regulators that you learned about in this module

repressor and activator

During translation, the codons on the mRNA are read and the respective amino acids are incorporated into the protein. This occurs on the surface of the

ribosome

Viruses are not included in the three domain system of classification because

they are not living organisms.

Viruses are called intracellular obligate organisms because

they require a host cell to replicate within

An anaerobic bacteria does not require oxygen.

true

Bacteria that can form endospores are generally more resistant to treatment and control methods than the bacteria that do not make endospores.

true

Catabolic reactions (that breakdown of complex molecules into simple ones) releases energy that is used in anabolic reactions (building complex molecules from simple ones)

true

During aerobic respiration, the electrons from glucose molecule are transported through a series of reactions to oxygen. The energy of the electrons, that is released in the process, is used to synthesize ATP.

true

During anaerobic respiration, bacteria transport electrons from donors to acceptors other than oxygen.

true

During transcription, only one strand of DNA is used as a template to make the RNA

true

Each organism has an optimum temperature of growth.

true