BIO 225: TTC: EXAM 1 (CH 1, 3, 4, 8) Recharge
Carl Woese and George Fox developed the three-domain system of taxonomy based on what molecular discovery?
Variations in the ribonucleic acid of the small ribosomal subunit of organisms
Which group of microorganisms is composed only of hereditary material wrapped in a protein covering?
Viruses
Bacterial conjugation involves ________.
a donor cell with a plasmid that synthesizes a pilus
Spirochetes are able to move due to ________.
a periplasmic flagellum
A saprobe differs from a parasite in that ________.
a saprobe acquires its nutrients from the remains of dead animals or plants whereas a parasite acquires its nutrients from living tissue
The _____ stain is used to stain and differentiate Mycobacterium and Nocardia from other bacteria.
acid-fast
DNA Polymerase III ________.
adds new bases and proofreads new DNA
Replication of DNA begins at a(n) ________ rich area.
adenine-thymine.
All microorganisms are best defined as organisms that ________.
are too small to be seen with the unaided eye
The two functions of bacterial appendages are ________.
attachment and motility
Which structure protects bacteria from being phagocytized by white blood cells?
capsule
The site(s) for most ATP synthesis in bacterial cells is(are) the _____.
cell membrane
All of the following are found in some or all protozoa except ________.
cell wall
If bacteria living in salty seawater were displaced to a freshwater environment, the cell structure that would prevent the cells from rupturing is the ________.
cell wall
Peptidoglycan is a unique macromolecule found in bacterial _____.
cell walls
Bacterial cells could have any of the following appendages except _____.
cilia
The orderly arrangement of organisms into a hierarchy of taxa is called _____.
classification
A three base sequence on mRNA is called a(n) _____.
codon
Taxonomy does not involve _____.
common name
During unfavorable growth conditions, many protozoa can convert to a resistant, dormant stage called a(n) _____.
cyst
The microorganisms that recycle nutrients by breaking down dead matter and wastes are called _____.
decomposers
A frameshift is caused by ______ mutations.
deletion and insertion
A scientist studying the sequence of nucleotides in the rRNA of a bacterial species is working on ________.
determining evolutionary relatedness
In humans, helminths generally infect the _____.
digestive tract
Fungi that grow as yeast at one temperature but will grow as mold at another temperature are called _____.
dimorphic
The cell _______ can be composed of three layers: the cytoplasmic membrane, the cell wall, and the outer membrane.
envelope
The process in which mutations are removed and the correct bases added is called _____.
excision repair
Select the correct descending taxonomic hierarchy:
family, genus, species
Amoebiasis (amoebic dysentery) is most commonly contracted through the ________.
fecal-oral route from contaminated food or water
Two major structures that allow bacteria to adhere to surfaces are _______ and _______.
fimbrae; capsules
The short, numerous appendages used by some bacterial cells for adhering to surfaces are called _____.
fimbriae
A bacterial cell exhibiting chemotaxis probably has _____.
flagella
The most serious type of mutation is a ________.
frameshift mutation
Fungal spores differ from bacterial endospores in that ________.
fungal spores are reproductive, whereas bacterial endospores are for survival
A technique that separates a readable pattern of DNA fragments is ________.
gel electrophoresis
Each _______ is a specific segment of the DNA with the code for production of one functional product.
gene
A bacteriophage transfers DNA of the previous host to the current host. This is an example of ________.
generalized transduction
The various techniques by which scientists manipulate DNA in the lab are called ________.
genetic engineering
The _____ is all of the genetic material of a cell.
genome
During the Gram stain, _____ cells decolorize when the alcohol is applied.
gram-negative
Lipopolysaccharide is an important cell wall component of _____.
gram-negative bacteria
A bacterial cell wall that has primarily peptidoglycan with small amounts of teichoic acid and lipoteichoic acid is _____.
gram-positive
Lysozyme is most effective against _____.
gram-positive organisms
All of the following pertain to nitrogenous bases except ________.
guanine pairs with uracil
Halobacterium salinarium (italicized) lives in and requires salt. This is an example of an archaeabacterium described as a(n) _______.
halophile
Which statement best describes the flow of genetic information in a cell?
DNA codes for RNA, which codes for proteins and some information from RNA flows back to DNA in a regulatory role.
In recombinant DNA technique, what enzyme is needed to seal the sticky ends of genes into plasmids or chromosomes?
DNA ligase
Okazaki fragments are attached to the growing end of the lagging strand by _____.
DNA ligases
The enzymes that can proofread replicating DNA, detect incorrect bases, excise them, and correctly replace them are _____.
DNA polymerases
Adulthood and mating of helminths occur in which host?
Definitive host
Which activity is an example of biotechnology?
Escherichia coli producing human insulin
Which area of biology states that living things undergo gradual, structural, and functional changes over long periods of time?
Evolution
If you start with three double-stranded DNA fragments, after four cycles of PCR you will have _______ fragments.
48
DNA is denatured at _____.
94 C
The best definition of endosymbiosis is ________.
A pre-eukaryotic cell was infected by a prokaryote, and symbiosis between the two cell types gave rise to the modern-day eukaryotic cell
Which PCR step synthesizes complimentary DNA strands?
Add DNA polymerase and nucleotides at 72°C
Eukaryotic chromosomes differ from bacterial chromosomes because only eukaryotes have ________.
All of the choices are correct (histone proteins, chromosomes in a nucleus, several to many chromosomes, elongated- not circular- chromosomes)
Analysis of DNA fragments in gel electrophoresis involves ________.
All of the choices are correct (larger fragments that move slowly and remain closer to the wells, DNA that has an overall negative charge and moves to the positive pole, DNA fragments that are stained to see them, an electric current through the gel that causes DNA fragments to migrate)
Common vectors used to transfer a piece of DNA into a cloning host are ________.
All of the choices are correct (plasmids, viruses, bacteriophages, artificial chromosomes)
Among the microorganisms, various genomes can include _____.
All of the choices are correct. (chromosomes, plasmids, mitochondrial DNA, chloroplast DNA)
RNA molecules differ from DNA molecules because only RNA ________.
All of the choices are correct. (has ribose, has uracil, is typically one strand of nucleotides, does not have thymine)
Endospores are ________.
All of the choices are correct. (metabolically inactive, resistant to heat and chemical destruction, resistant to destruction by radiation, living structures)
Which of the following is not classified as a helminth?
All of the choices are helminths. (Tapeworm, Fluke, Flatworm, Roundworm)
Mastery of synthetic biology will allow humans to ________.
All of the choices are possibilities from synthetic biology (make new organisms using only chemicals as the starting materials, synthesize chemicals in cells that are missing due to a genetic anomaly, construct complex molecules in situ that will target cancerous cells in tissues, design alternative forms of energy production)
Which of the following is not true of transposons?
Are always part of plasmids
Which of the following is not true of an organism's genotype?
Are the expressed traits governed by the genes
If you were a microbiologist in 1950, which of the following scientific principles would you already know?
Aseptic techniques could reduce the number of wound infections in the surgical setting.
What three components comprise the flagellum, extending from the cytoplasm to the exterior of the cell?
Basal body, hook, filament
_____ Manual of Systematic Bacteriology is a manual of bacterial descriptions and classifications.
Bergey's
If the mRNA codon for alanine is GCA, then the correct anticodon would be _____.
CGU
When bacteriophages invade bacterial cells, they leave behind DNA that is recognized by the bacteria as foreign and can be eliminated in the event of another attack, reminiscent of adaptive immunity. This natural process can be adapted in the lab so that a combination of guide DNA and nucleases facilitate the cutting of DNA at a precise location in any organism. Here we are describing ________.
CRISPR
The scientist(s) who proposed organisms be assigned to one of three domains is(are) _____.
Carl Woese and George Fox
Which order below reflects the correct procedure for Gram staining?
Crystal violet-iodine-alcohol/acetone-safranin
Which statement below supports the argument that gram-negative cells are structurally weaker than gram-positive cells?
Gram-negative cells have a thinner layer of peptidoglycan in their cell wall compared to gram-positive cells.
Which of the following is not true of conjugation?
It transfers genes for a polysaccharide capsule.
Which of the following is not a characteristic of bacteria?
Its DNA is wrapped around histones.
Which of the following is a taxon that contains all the other taxa listed?
Kingdom
Which of the following is a unique characteristic of viruses that distinguishes them from the other major groups of microorganisms?
Lack cell structure
Which of the following is not a human use of microorganisms?
Manufacturing copper wire
Which molecule is synthesized as a copy of a gene on the DNA template strand?
Messenger RNA
If the wild-type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE THE BAG RAT?
Missense
Which of the following is not considered a microorganism?
Mosquito
A bacterial genus that has waxy mycolic acid in the cell walls is _____.
Mycobacterium
If the wild-type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATE (stop)?
Nonsense
Which of the features listed below is not found in all cells?
Nucleus
Which is incorrect about purines?
Only found in DNA, not in RNA
Which is not a characteristic of fungi?
Photosynthetic
Organisms were classified into kingdoms as they were defined. Which list reflects the order of discovery of the kingdoms as we know them today?
Plants and animals, protista, monera, fungi
Which of the following is mismatched?
Plasmids - genes essential for growth and metabolism
After returning from a trip to Africa, Tom begins to feel very tired and weak. He has severe anemia. A blood smear reveals a protozoan is present in his blood. The health care provider tells Tom he has malaria. Which of the following could be the causative agent of his disease?
Plasmodium falciparum
Which is mismatched?
Plasmodium — protozoan that causes Chagas disease
For DNA replication, a primer of ________ is needed at the origin of nucleotide addition.
RNA
Gene regulation can involve a protein repressor that blocks _____ from initiating transcription.
RNA polymerase
Helicase ________.
unzips DNA
Split genes ________.
use spliceosomes to excise introns and then join exons
The outcome of the Gram stain is based on differences in the cell's _____.
wall
Fungal spores arise ________.
when asexual reproduction produces sporangiospores and conidiospores, and sexual reproduction produces spores, often from a fruiting body
A recombinant organism is one that ________.
has obtained genetic material from another organism that has integrated into the genome, combining the two DNA molecules
The difference in cell wall structure of Mycobacterium and Nocardia compared to the typical gram-positive bacterial cell wall structure is that they ________.
have a predominance of unique, waxy lipids
Larvae and eggs are developmental forms of _____.
helminths
Base pairs in DNA are held together by _____ bonds.
hydrogen
The long, threadlike branching cells of molds are called _____.
hyphae
DNA polymerases used in PCR ________.
include Taq polymerase
All of the following structures contribute to the ability of pathogenic bacteria to cause disease except the _____.
inclusions
The discovery of single nucleotide polymorphisms in the human genome means that ________.
individual risk for specific diseases can be analyzed, and personalized medicine designed as a result of the analysis
A sequence of bases on a eukaryotic gene that does not code for protein is called a(n) _____.
intron
The lactose repressor protein ________.
is inactivated by binding lactose
The bacterial chromosome ________.
is part of the nucleoid
Full induction of the lactose operon requires ________.
lactose present without glucose
Genomic _______ are collections of isolated genes maintained in a cloning host.
libraries
The term that refers to the presence of a tuft of flagella emerging from the same site is _____.
lophotrichous
The enzyme _______, found in tears and saliva, can hydrolyze the bonds in the glycan chains of certain bacterial cell walls.
lysozyme
The group of protozoa that have flagella are the _____.
mastigophora
Living things ordinarily too small to be seen with the unaided eye are termed _____.
microorganisms
Protozoan endoplasm contains _____.
mitochondria
Filamentous fungi are called _____.
molds
Chemotaxis refers to the ability to ________.
move in response to a chemical
A permanent, inheritable change in the genetic information is called _____.
mutation
The woven, intertwining mass of hyphae that makes up the body of a mold is a _____.
mycelium
Fungal infections are known as ________ and can be acquired from environmental or clinical sources.
mycoses
A mutation that changes a normal codon to a stop codon is called a ________.
nonsense mutation
The DNA of microorganisms is made up of subunits called _____.
nucleotides
All of the following pertain to transcription except ________.
occurs on a ribosome in the cytoplasm
The antiparallel arrangement within DNA molecules refers to ________.
one helix strand that runs from the 5' to 3' direction and the other strand runs from the 3' to 5' direction
All bacterial cells have ________.
one or more chromosomes
Each nucleotide is composed of ________.
one phosphate, one nitrogenous base, and one sugar
Restriction endonucleases recognize and clip at DNA base sequences called _____.
palindromes
Sequences of DNA that are identical when read from the 5' to 3' direction on one strand and the 3' to 5' direction on the other strand are _____.
palindromes
Cells form a ______ arrangement when cells in a chain snap back upon each other forming a row of cells oriented side by side.
palisade
Helminths are _____.
parasitic worms
Disease-causing microorganisms are called _____.
pathogens
Spirochetes have a twisting and flexing locomotion due to appendages called _____.
periplasmic flagella (axial filaments)
The term that refers to the presence of flagella over the cell surface is _____.
peritrichous
The expression of genetic traits is the _____.
phenotype
DNA fragments can be separated in gel electrophoresis because ________.
phosphate groups have a net negative charge
The study of evolutionary relationships among organisms is called _____,
phylogeny
Amplification of DNA is accomplished by ________.
polymerase chain reaction
Movement of a cell toward a chemical stimulus is termed _____.
positive chemotaxis
Cells, like bacteria and archaea, that do not have a nucleus in their cells have traditionally been called _____.
prokaryotes
The nontranscribed region of DNA to which RNA polymerase binds to initiate transcription is called the _____.
promoter
The function of bacterial endospores is ________.
protection of genetic material during harsh conditions
The most immediate result of destruction of a cell's ribosomes would be ________.
protein synthesis would stop
When buds remain attached, they form a chain of yeast cells called _____.
pseudohyphae
The chemical components of ribosomes are proteins and _____.
rRNA
The deliberate removal of genetic material from one organism and combining it with the genetic material of another organism is a specific technique called ________.
recombinant DNA technology
The gene that codes for a protein capable of repressing an operon is called the _____.
regulator
DNA Polymerase I ________.
removes primers
The duplication of a cell's DNA is called _____.
replication
The site where the old DNA strands separate and new DNA strands will be synthesized is called the _____.
replication fork
Parasitic worms have a highly developed ______ system.
reproductive
If you looked at a _______ under the microscope, you would likely see an irregular cluster of spherical cells.
staphylococcus
A chain of rod-shaped cells would be called a(an) _____.
streptobacillus
Synthesis of an inducible enzyme requires ________.
substrate bound to repressor
DNA polymerase III ________.
synthesizes new DNA only in the 5' to 3' direction
The primers in PCR are ________.
synthetic short strands of DNA (oligonucleotides)
During replication, each parent DNA strand serves as a _______ for synthesis of new DNA strands.
template
The emerging field of synthetic biology, while offering promising breakthroughs in medicine and energy production, is not without concern. Apprehension by ethicists is understandable since ________.
the ability to create life from scratch raises a multitude of issues
The basic premise of gene therapy is that ________.
the error in protein production from a defective gene is overcome by the insertion of the correct gene from a healthy cell into the patient's tissue
During DNA replication, synthesis of the leading strand of DNA differs from the synthesis of the lagging strand in that ________.
the leading strand is synthesized continuously toward the replication fork, whereas the lagging strand extends away from the fork and is synthesized in short segments called Okazaki fragments
The following pertain to ribosomes during protein synthesis except ________.
they participate in both transcription and translation
The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called _____.
transfer RNA
The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is _____.
transformation
The jumping of a gene from one location to another is done by _____.
transposons
The motile, feeding stage of protozoa is called the _____.
trophozoite
All of the following are helminths except _____.
trypanosomes
Which scientific field is involved in the identification, classification, and naming of organisms?
Taxonomy
Which term is not used to describe bacterial cell shapes?
Tetrad
A new field of research called nutrigenomics is based on the premise that individuals gain or lose weight according to differences in their individual genomes, making "going on a diet" no longer a one-size-fits-all solution. This is based on what genomic principle?
The human genome contains 10 million SNPs.
Which of the following is incorrect about transfer RNA?
The initiator tRNA in bacteria carries tryptophan.
Which of the following statements best describes the initiation of translation?
The mRNA containing the start codon, AUG, sits at the P site and forms a complex with the corresponding tRNA, and the large and small ribosomal subunits.
Which of the following statements applies to both DNA and RNA?
The molecule is synthesized in the 5'-3' direction when a polymerase adds a nucleotide onto the 3' end of the existing polymer.
Which of the following is not true of the outer membrane?
Gram-positive bacteria have an outer membrane.
Which is incorrect about inducible operons?
Have genes turned off by a buildup of end product
Which PCR step causes the denaturation of double-stranded DNA?
Heat target DNA to 94°C
Which of the following are mismatched?
Heterotroph - synthesize organic nutrients using light energy and CO2
Which cell can transfer chromosomal and plasmid genes to a recipient cell by conjugation?
Hfr cell
Which of the following describes the relationship between the fungal hyphae and mycelia?
Hyphae are filamentous cells that grow together in an intertwined mass called a mycelium.
Which of the following does not pertain to helminths?
In kingdom Protista
Which of the following is incorrect about termination codons?
Include AUG
If the wild-type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATA ETH EBI GRA T?
Insertion
Larval development of helminths occurs in which host?
Intermediate (secondary) host
Which of the following does not pertain to endotoxin?
It is found in acid-fast bacterial cell walls
What type of mutation alters the base, but not the amino acid being coded for?
Silent
Which of the following is not associated with a bacterial ribosome?
Small unit provides the enzymes for making peptide bonds
Bacterial endospores are not produced by _____.
Staphylococcus
Which scientific name is written correctly?
Staphylococcus aureus (italicized or underlined)
Which of the following is a scientific name?
Streptococcus pyogenes (italicized)
Three consecutive bases in the DNA of a gene represent the code for one _____.
amino acid
The term that refers to flagella at both poles is _____.
amphitrichous
Semiconservative replication refers to ________.
an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule
The group of protozoa that have gliding motility are the _____.
apicomplexa/sporozoa
Protozoan cysts ________.
are helpful in surviving unfavorable conditions
Gram-negative bacteria
are less susceptible to antibiotics that target peptidoglycan than gram-positive organisms.
Plasmids ________.
are often the site of pathogenic genes
A flagellum is anchored into the bacterial cell envelope by its _____.
basal body
The size of DNA is often given in the number of ______ that it contains.
base pairs
Using microbes to detoxify a site contaminated with heavy metals is an example of _____.
bioremediation
When assigning a scientific name to an organism,
both genus and species names are italicized or underlined.
The most prevalent worldwide infectious diseases are _____.
respiratory diseases
DNA strands can be clipped crosswise at selected positions by using enzymes called _____.
restriction endonucleases
EcoRI and HindIII are ________.
restriction endonucleases
Geneticists can make complimentary DNA from messenger, transfer, and ribosomal RNA by using _____.
reverse transcriptase
Most fungi obtain nutrients from dead plants and animals. These fungi are called _____.
saprobes
The group of protozoa that use pseudopodia to move are the _____.
sarcodina
The transfer of genes during bacterial conjugation involves rigid, tubular appendages called _____.
sex pili
The benefit of the bacterial operon is that ________.
since the proteins coded for by the operon structural genes work as a team, they are regulated (i.e. induced or repressed) as a team, thus saving energy
The development of virulent, toxin-producing bacterial strains due to the presence of a temperate phage can occur in ________.
specialized transduction
The smallest and most significant taxon is _____.
species