Micro Lec test 1

Cellular growth can be visualized by:

*an increase in cellular components *an increase in cell size *an increase in cell number

Transposons (jumping genes)

*mobile genetic elements *move from place to place in the genome, plasmid and viral genomes *disrupt genes when they land *may mobilize other genes (like antibiotic resistance)

How many cells or colony-forming units (CFUs) are presumed to result in a single colony using the variable plate method?

1

which of the following describes the primary "function" of the cell membrane?

a barrier between the internal and external contents of the cell.

another term for the cell membrane (or plasma membrane) in the __________________ membrane.

cytoplasmic

the cell membrane may also be referred to as the

cytoplasmic membrane

the taxonomic categories from top to bottom are:

domain kingdom phylum/division class order family genus species

The theory of ________ states that living things change gradually over time through natural selection.

evolution

which of the following bacterial growth phases correlates to the acute stages of a bacterial infection?

exponential

which term describes the length of time of a microbial species needs to divide?

generation time

what technology involves the deliberate modification of the genetic structure of an organism to create novel products?

genetic engineering

All bacteria possess a cell ________ but not all bacteria possess a cell ________.

membrane wall

During translation initiation, the ribosomes bind to the __________ RNA transcript.

messenger

the sum total of all the microbes in a certain environment is its ___________.

microbiome

in the 1600s, van Leeuwenhoek developed a large collection of single-lens _________.

microscope

Organisms that are only visible with the aid of a microscope are __________.

microscopic

________ microbes that are associated with humans cause no harm.

most

the ___________ bacteria have no cell wall, but have a cytoplasmic membrane that is stabilized by sterois.

mycoplasma

illustrate the scientific method by putting these statements in order, starting with the first process at the top.

1. A phenomenon is observed in the natural world. 2. The scientist develops an explanation known as a hypothesis. 3. An experiment is conducted to test the hypothesis. 4. Analysis leads to either rejection or support of hypothesis.

Phases or Order of normal bacterial growth curve.

1. Lag 2. Exponential 3. Stationary 4. Death

The human Microbiome Project began in

2008

What is the function of rRNA?

comprises ribosomal subunits

The genetic transfer of material through pili is termed

conjugation

cellular growth

is stimulated by nutrients and environmental factors

all of the following are true statements about the human microbiome EXCEPT ____________.

it regularly causes disease

The ___________ of the genetic code results in several codons encoding the same amino acid.

redundancy

older diseases that are experiencing recent increases in prevalence are referred to as ___________.

reemerging diseases

Bacteriophage

"middle man" transfers small pieces of DNA during infection process

Which three of the following events in protein synthesis occur post-transitionally.

*addition of cofactor *removal of the formyl methionine *protein folding

The anticodon of the tRNA carrying the codon GUU is ______.

CAA

Transformation Griffith and avery

Dead pathogenic Streptococcus pneumoniae (Pneumococci) were able to "transform" live non pathege

which 2 of the following statements regarding genome size are correct?

Eukaryotes generally have more genes than viruses. Genomes vary greatly in size

Is the transcriptional process shown in the image from a prokaryotic cell, a eukaryotic cell or both?

Eukaryotic

In eukaryotes, coding regions of DNA that will be translated into protein are called ___________.

Exons

____________ is the light-fueled conversion of carbon dioxide to organic material.

Photosynthesis

Which were the five kingdoms in the earlier Whittaker system of classification?

Plantae monera protista fungi animalia

RNA polymerase binds to which region of DNA to begin transcription?

Promoter

which of the following is the genetic pattern of viral genomes?

Single or double stranded DNA or RNA

A rigid helical bacterial cell twisted twice or more along its axis is described as a:

Spirillum

chose the prefix that may be used to describe arrangements of bacilli:

Strepto- diplo-

Infectious disease are among the top ten causes of death by disease both in the U.S. and worldwide.

True

Microbiology involves the study of microscopic organisms or agents, including ___________.

bacteria helminths fungi viruses protozoa archaea

________ diseases are those which are newly identified and becoming more prominent.

emerging

The transcriptional process shown in this image is from a _________ cell.

eukaryote

the microbe depicted in this image is an example of a

fungi

In binary fission, the doubling time of a particular microbial species is also known as its ____________ time.

generation

for the organism Staphylococcus aureus, Staphylococcus represents the _________ level of classification.

genus

Which is the main event of translation initiation?

mRNA binds to the ribosome

The __________ bacteria naturally have no cell wall, but have a cytoplasmic membrane that is stabilized by sterols.

mycoplasma

Which two macromolecules are the major component of cell membranes?

proteins lipids

The five kingdoms in the Whittaker system include Kingdoms Animalia, Plantae, Myceteae (fungi), ___________, and ___________.

protista monera

________ and proteins compose ribosome subunits.

rRNA

The deliberate manipulation of organisms by transferring genetic material from one organism to another, a type of genetic engineering, is known as ______________ DNA technology.

recombinant

The _____________ is a particle composed of two subunits of rRNA that is of protein synthesis.

ribosomes

A coccus is a _________ -shaped bacterial cell.

spherical

a ________ is a flexible, spiral-shaped bacterium.

spirochete

the prefix "___________" means "in grape-like clusters."

staphylo

The _________ phase of bacterial growth is when there is an equal number of cells dividing as there are dying.

stationary

The __________ phase of bacterial cell growth is when there is an equal number of cells dividing as there are dying.

stationary

During which phase of growth does the number of new cells balance the number of declining cells?

stationary phase

A curved rod (comma-shaped bacterium) is specifically described as a:

vibrio

A __________ is a microscopic agent, which is not cellular (acellular) and is composed of nucleic acids surrounded by a protein coat.

virus

Horizontal gene transfer

Transfer of DNA from a source other than the parent organisms.

Hfr Strains

*High Frequency of recombination *Integrated F factor (episome) *Conjugal transfer *chromosomal gene introduced *incorporation of new genes into the chromosome *these were used to "map" the relative positions of genes before DNA sequencing became so easy

Generalized Transduction

*Involves a lytic phage *infection as usual *Mistaken packaging of a host gene *defective phage *one in a million odds

Specialized Transduction

*Lysogenic phage *inserts as prophage *aberrant excision *pick up adjacent gene *defective phage *one in a million odds

Which two of the following statements regarding eukaryotic transcription are correct?

*Splicing to remove introns occurs in the nucleus. *A series of adenosines is added to the mRNA

In a stratified biofilm, :

*aerobes are found near the surface *anaerobes are found near the bottom

cellular growth can be visualized by:

*an increase in cell number *an increase in cell size *an increase in cellular component

A codon contains how many nucleotides?

3

What is the length of a typical tRNA molecule?

75-95 bases

Escherichia Coli generation time of 20 minutes. if 1 million parent cells where placed in a flask of sterile nutrient broth and incubated under optimal conditions, how many cells would be present in the broth after 1 hour?

8 million

which is the main event of translation termination?

A nonsense codon is reached and the peptide is released from the ribosome

which of the following can be measured or analyzed in an uncultured environment or tissue sample in order to qualify cell numbers present?

ATP

The Dutch linen merchant who developed a large collection of single-lens microscope in the late 1600s that used to view microbes was _________.

Antonie van Leeuwenhoek

The three domains of the Woese-fox system include the rure bacteria in Domain Bacteria, the extreme microbes in Domain ___________, and the eukaryotic organisms in Domain _____________.

Archaea Eukarya

which are the three domains of the Woese-Fox system of classification?

Archaea Eukarya Bacteria

__________ is the area of taxonomy that involves grouping similar organisms into a hierarchy of taxonomic categories.

Classification

What is the correct term for describing very short, ovoid, rod-shaped bacterial cells.

Coccobacilli

What are the three most common shapes of bacterial cells?

Bacillus Coccus Spirillum

typical bacteria, such as Bacillus or Streptococcus, belong to which domain?

Bacteria

In eukaryotes, which DNA sequences encode functional protein?

Exons

A person shedding bacteria in the late stages of infection is more likely to spread in to others than a person in the early or middle stages.

False

A sterile environment is free of actively growing cells and microorganisms, but may contain viruses or dormant life forms such as endospores.

False

Plasmids are insertion sequences that can lead to changes in genotype within a cell or between cells.

False

The different coccal arrangement are a consequence of growth in broth solid media.

False

Viral genomes are always composed of either single or double stranded DNA

False

based on research, microbes have been recently associated with which four of the following diseases that were once considered noninfectious?

Gastric Ulcers Cancer Diabetes Multiple sclerosis

which microbes have a true nucleus?

Protists yeast

Which term describes the length of time of a microbial species needs to divide?

Generation time

human, bacterium, virus

Human= tens of thousands of genes Bacterium= a few thousand genes Virus= a few dozen genes

_________ is the term applied to the method of assigning a scientific name to an organism, whereas taxonomy involves the organization of these named organisms.

Nomenclature

The viable colony count is based on the principle that each colony isolated represents ____________ cell or colony-forming unit from the original sample.

One

only gram-negative bacteria posses an

Outer membrane

which process can be used to quantify cell numbers in a sample without culturing the actual microb?

PCR

out of the answers given, choose the most general and the most specific level in the hierarchy of classification.

Species kingdom

A _________ is a flexible, spiral-shaped bacterium.

Spirochete

_________ is the science of organizing, classifying and naming living things.

Taxonomy

which two of the following statement regarding tRNA structure are correct?

The overall structure is termed a cloverleaf tRNA has regions that are double-stranded RNA

What is biotechnology?

The use of microbes or their products for commercial or industrial purposes.

Several codons code for the same amino acid, which is called the redundancy of the code.

True

when writing a binomial name, the initial letter of the genus is capitalized and the species is in lower case.

True

The structures seen in this figure are representatives of different types of _________.

Viruses

During translation elongation, peptide bonds form between:

amino acids

what is classification?

arranging organisms into a hierarchy

For the organism Staphylococcus aureus, what is the species name?

aureus

the proper term for a rod-shaped bacterial cell is a

bacillus

which two of the following group of organisms arguably play the greatest role in biological decomposition?

bacteria fungi

Transduction

bacteriophage transfers from cell to cell

In the __________ system of nomenclature, organisms are assigned and identified by a two-word name representing the genus and species names.

binomial

Conjugation Plasmid direct transfer

cell contact

Conjugation

cell contract-Fertility pilus-allows transfer of large amounts DNA from donor to recipient. *Requires physical contact between donor and recipient cells *Fertility plasmid codes for Fertility pilus *large amount of DNA transfer may occur

the prefix "strepto-" is used to indicate that the cells are arranged in

chains

Taxonomy involves ______________ living things.

classifying

the prefix "staphylo-" is used to indicate that the cells are arranged in:

clusters

The term used for a short, plump bacterial rod is __________.

coccobacilli

A ____________ is the specific sequence of 3 mRNA nucleotides, based n a DNA triplet, that encodes a particular amino acid.

codon

the genetic transfer of material through pili is termed _________.

conjugation

Lipopolysaccharide (LPS) is found on the outer membrane of Gram-negative cells. Within the outer membrane it is located:

on the outer surface

what is a helminth?

parasitic work

Louis _______ developed methods of making dairy products safer and the formation of beer and wine using microbes.

pasteur

in general, disease-causing organisms are referred to as

pathogens

A major structural component, ___________ are found within the lipid bilayer in a cell membrane and comprise 30-40% of the membrane mass.

phospholipids

"Finishing touches" on proteins are termed ____ modification.

posttranslational

The arrow is pointing to a ______ cell type.

prokaryotic

RNA polymerase bind to the ___________ region to initiate transcription.

promoter

rRNA composes ________ subunits together with protein.

ribosomes

A bacillus is a ________- shaped bacterial cell.

rod

the exocytosis or the transport of metabolic materials from a cell into the extracellular environment is referred to as ________.

secretion

what term refers to the discharge of a metabolic product to the extracellular environment?

secretion

Natural _________ is a process in which the environment places pressure on organisms to adapt and survive; traits best suited to the environment tend to spread in the population over time.

selection

the cell membrane is a _______ permeable barrier of the cell.

semi

What is the function of mRNA

serves as a transcript of a gene sequence of template DNA

an environment or material that is completely free of all life forms (including spores) and viruses particles is referred to as

sterile

which event helped establish the science of microbiology?

the development of the microscope

Enumeration of bacteria can be achieved by the _________ cell count, in which a cell suspension in a chamber is viewed under the microscope.

total

Which 2 statements regarding eukaryotic are correct?

transcription occurs before splicing the exon-intron junction is recognized by a spliceosome.

Vertical gene transfer

transfer of DNA from parent organisms during reproduction

Transformation

transfer of small segments of DNA from a dead cell