What is mircobiology?
the study of living organisms that are individually too small to be seen clearly with the unaided eye
What percent of bacteria cause human disease?
What percent of bacteria cause plant disease?
What percent of bacteria are non pathogenic?
What is spontaneous generation (SG)?
where the bacteria came from, where significant growth started
Who was the first to discover living microbes and invented the single lense microscope?
Antonie van Leeuwenhoek
Who discovered spontaneous generation through experimenting with flies and uncovered vs. covered meat?
Who developed the small pox vaccine and is referred to as the father of immunology?
Who prevented "child birth fever" by establishing hand washing and chlorine before surgery?
Who disproved spontaneous generation by using a long neck flask and develope the process of pasteurization?
Who is the father of antiseptic surgery, sanitation, and hygiene procedure; as well as listerine (chemical inhibition of infection)?
Who developed the first link between a single microbe and a single disease (tuberculosis)?
Who are the members of the five kingdom system?
monera (prokaryotics/bacteria and archaea), protista (single celled eukaryotes), fungi (single and multi-cellular), plantae, and animalia
What two kingdoms are closely related to kindom animalia?
protozoa and fungi
What three kingdoms are closely related to protozoa?
animalia, plantae, and fungi
What kingdom is closely related to bacteria?
List the taxonomic heirarchy.
Kingdom, Phylum, Class, Order, Family, Genus, Species, Strain
a collection of bacterial strains that share many common physiologica and genetic features
variations within a species, and descended from a single organism
What is a subspecies?
groups of strains within the same species based on certain biovar
What is a biovar?
a biotype, biochemival or physiological differences between or among strains
What are specific characteristics displayed by the organism?
What is a genome?
genetic information contained in the DNA
What is a population of cells derived from the same parent?
Who proposed the threem domain system and what is it based on?
Carl Woese; based on the difference in rRNA, cell wall in prokaryotic organisms and antibiotic resistance
What are the members of the three domain system?
Eukarya (all eukaryotes), Archaea (ancient bacteria), Eubacteria (true bacteria and cyanobacteria)
What are phenotypic characteristics?
cell morphology, size, shape, arrangement, staining characteristics, biochemical reaction
What are biochemical characteristics?
detection of enzymes produced, substrates and other products produced
What is categorization of strains within a certain species called?
typing (can be based on antigen/antibody or on DNA)
What is evolution?
change in a line of descent over time leading to a new species
What is the study of evolutionary relationship?
Which rRNA is used for bacteria and which is used for fungi?
16s rRNA is used for bacteria and 18s rRNA is used for fungi
True or False: rRNA is present in all cells.
What are the three ways of typing?
staining, serology, and rRNA
What is specificity and how is it calculated?
this is the most important component of diagnostic testing and is the capacity of the test to yeild a positive result for the target molecule only
[(true negatives) / (true negatives - false positives)] x 100
What is sensitivity and how is it calculated?
the ability of the test to detect small amounts of the target
[(true positives) / (true positives - false negatives)] x 100
What may cause poor results with the traditional (non PCR) methods?
cannot detect intracellular bacteria, they have a low sensitivity, seropositivity is common, subtyping is mandatory, slow microbial growth
Who developed PCR in the 1980's?
What is PCR?
a technique for making many copies of a specific DNA sequence and amplifying it
What makes PCR more specific than other tests and what makes it more sensitive?
the use of DNA makes it specific and amplification make it more sensitive
Which nitrogen base is only in DNA and which one is only in RNA?
Thymine is only in DNA and Uracil is only in RNA
What are the components of a nucleotide?
base, surgar (deoxyribose or ribose), and phosphate
What are the components of a nucleoside?
base, and sugar (deoxyribose or ribose)
What is the structural difference between deoxyribose and ribose?
deoxyribose has a hydrogen in the 2' position and ribose has a OH group in the 2' position
Which two nirtogen bases have two bonds in their complimentary hybridization and which two have three bonds?
Adenine and Thymine have two bonds and Guanin and Cytosine have three bonds
Which nitrogenous base concetration would make double stranded DNA more tightly bound?
an increase in G-C concetration increase the strength of DNA and also increase the temperature necessary for denaturation/melting
What are the components of a PCR reaction?
template DNA (the sequence you are looking for)
primers (short oligonucleotides that you know the sequence for)
DNA polymerase (enzyme that elongates and amplifies)
What are the steps of the PCR thermal cycle?
heat denaturation (92-95 degrees) for 1 min
primer annealing (complimentary hybridization) (~55 degrees) for 4 sec
primer extension (72 degrees) for 2 min
True or False: Classical PCR is quantitative and Real Time PCR is qualitative.
False; classical PCR is qualitative and real time PCR is quantitative
True or False: Real time PCR has primers for amplification and probes for detection however classical PCR only has primers.
How does SYBR-green work?
when SYBR-green comes in contact with double stranded DNA you see an increase in florescence
How does FRET work?
two florescence are added that are conjugated to an oligonucleotide probe; if the second probe binds adjacent to the first probe the energy is transferred and there is florescent light emitted; the stronger the florescence the higher the concetration of DNA
What are three perks with real time PCR that are not available with classical PCR?
Real-time PCR limits contamination, you can tell how much of the specific DNA is actually present, and you can detect up to 5 subtype targets
What are some rules of sampling?
do not freeze and thaw the sample, EDTA whole blood is the most often used specimen, do not use heparin as an anticoagulant
What is the morphology of yeast?
What is the morpholgy of the mold?
What makes a fungal cell wall different from a plant cell wall?
a fungal cell wall is not photosynthetic
What are the three mechanisms of fungal asexual reproduction?
Sporulation (aspergillus and penicilium)
Fragmentation of the hyphae (cocidiodes immitis)
Budding (candida and cryptococcus)
What do fungi contain in their membrane?
they have a cytoplasmic bilayered membrane that contains sterols
Why can we use polysterene antibiotics?
because it has a higher affinity for fungal sterols than for cholesterols
What are the membranes/barriers from in to out of the fungal cell?
cytoplasmic membrane made of sterols, the cell wall made of polysaccharide chains, then the capsule composed of polysaccharides
Fungi rarely cause disease in healthy, immunocompotent animals; what is the exception?
What type of lesions do most fungi produce?
What type of hypersensitivity reaction is common with fungi?
delayed type hypersensitivity skin reaction
What agar do most mold grow in, and at what temperature?
sabouraud's dextrose agar at 20-25 degrees
What agar do most yeast grow in, and at what temperature?
5% blood agar at 37 degrees
What are the three species of yeast?
candida, malassazia, and cryptococcus
What part of the body does cryptococcus neoformans affect?
upper respiratory, eye, but mainly the central nervous system (meminges) especially in the cat
What are the three virulence factors for cryptococcus neoformans?
the capsule, melanin and mannitol, and phospholipase
What is the main reservior for cyptococcus neoformans?
dried pigeon droppings
What is the main animal of concern form crytpcoccus neoformans?
What clinical signs to we see in an animal with cryptococcus neoformans?
What problem does malassezia cause in dogs?
What is the only species of malassezia that is pathogenic?
True or False: Malassezia pachydermatis is part of the normal flora.
What is the main animals associated with candida?
Where is candida found in birds?
the crop and digestive system
What mold causes ringworm (tinea)?
Where in the body do dermatophytes reside?
in the epidermis (karatinized)
What are the two strains of dermatophytes?
micosporum and trichophyton
True or False: Dermatophytes can survive for years in the inanimate environment.
What are dermatophytes' enzymatic virulence factors?
keratinases, elastases, and collagenases
What is a differential diagnosis for dermatophytes?
What is the pathogenesis for dermatophytes?
the stratum corneum is damaged (hypertrophy) and candidium enters that cell which leads to hyphae and spore germination which start to invade the hair cortex, leading to ectothrix
What is circular rashes significant of?
What are the subcutaneous mycoses species?
sporothrix schenckii, histoplasma capsulatum var farciminosim, and oomycosis
Which subcutaneous mycoses is significant in cats due to zoonotic potential because of the high spore concentration?
What are the virulence factors of sporothrix schenckii?
cell wall (which allows survival in the macrophage) and adhesins
What are the components of sporothrix schenckii cell wall?
lipids: inhibits phagocytosis
Melanin: protects from reactive oxygen intermediates in the phagolysosome
Pepetide-rhamnomannan: suppresses the release of proinflammatory cytokines
Sialic Acids: inhibits uptake by phagocytes
What are the two forms of sporothrix schenckii?
cutaneous (skin) and disseminated (all over)
What is the main mode of transmission for sporothrix schenckii?
Explain the pathogenesis of sporothrix schenckii.
trauma causes ulcerating cutaneous nodules to develop followed by infection, supperating ulcers, and possible dissemination to viscera, joints, and CNS
Which of the subcutaneous mycoses is bioweaponized?
histoplasma capsulatum var farciminosum
What is the animal associated with histoplasma capsulatum var farciminosum?
What sucutaneous mycoses causes epizootic lymphangitis (pseudoglanders)?
histoplasma capsulatum var farciminosum
What cause pygranulomatous and has clinical signs of skin lesions cheifly on the head, neck, and limbs?
histoplasma capsulatum var farciminosum
Which subcutaneous mycoses caused African Horse Farcy?
histoplasma capsulatum var farciminosum
Which subcutaneous mycoses are not true members of the fungi kingdom?
True or False: Histoplasma capsulatum var farciminosum is classifed as water mold.
False; oomycosis is classified as water mold
What two species are a main concer for oomycosis?
horses and dogs (go into water with open wounds)
What is the main type of oomycosis found in animals?
cutaneous pythiosis also known as "swamp cancer" and "Florida horse leeches"
What is pythium insidiosum?
an oomycosis that causes ulcerative pyogranulomatous or fribrogranulomatous skin infections in horses, cattle, dogs, and cats
Yellow-choral like and gridy, discharging, swellong lesions usually on extremities, ventral trunk, or head are characteristic of what?
What is a mycetoma?
a specific lesion formed in the subcutaneous layer caused by curvularia
What are the types of systemic mycoses?
coccidioies, histoplasma capsulatum var capsulatum, blastomyces dermatitis, and apergillus
What two species cause coccidioidomycosis?
coccidioides immitis and coccidioides posadasii
Where can you find coccidioides immitis?
in central valley Florida
Where can you find coccidioides posadasii?
in New Mexico, Texas, Arizona, and South America
What is the main infected domestic animal of coccidioides?
What is the major virulence factor of coccidioides?
adhesins: glycoproteins on the surface of spherules which has affinity for extracellular matrix proteins and stimulates a strong Th2 response (IL-10) (high antibody, low cell mediated response)
What is the main transmission of coccidioides?
inhalation or skin
What is a clinical finding of coccidioides?
Explain the synthesis of histoplasma capsulatum var capsulatum.
attaches to macrophage in the lung preventing respiratory burst, then differentiate into yeast and survive the phagolysosome, multiplying and eventually rupturing it
What animal is histoplasma capsulatum var capsulatum common in?
What are the main virulence factors for blastomyces dermatitidis?
blastomyces adhesin 1 (Bad-1) which binds to surface phagocytic cells, triggering minimal respiratory burst with little generation of reactive oxygen and nitrogen intermediates
Explain the pathogenesis of blastomyces dermatitidis.
inhaled and converted to yeast in the alveolar spaces, Bad-1 is expressed with minimal respiratory burst and down regulation of cytokines, leading to an inflammatory response and result in pyogranulomatou lesion in the brochioles
True or False: Blastomycosis is more often progressive than histoplasma and coccidioides.
True or False: Aspergillus is gound in several different environments.
Which aspergillus species is more frequent in humans and animals?
What are the five virulence factors of apergillus?
adhesins, cell wall, extracellular enzymes, iron acquisition, and pigment
What is significant about apergillus cell wall?
it displays PAMPs that are recognized by TLR in macrophages (proinflammatory)
Which systemic mycoses cause pneumonia in birds and abortions and mastitis in ruminants?
Which systemic mycoses causes infection of mucous membranes in nasal passages or paranasal sinuses of dogs and cats?
Which systemic mycoses causes keratomycosis in horses?
Which microscope uses antigen antibody detection?
What are the three principles of the microscope?
magnification, resolving power, and contrast
What image does the objective lens capture and what does the ocular lens capture?
the objective lens captures the real image and the ocular lens forms the virtual image
How do you find the total magnification?
power of objective (10, 20, 40, or 100) times the powe of the ocular (10)
True or False: A wavelength less than 0.2um cannot be clearly resolved.
Describe light field vs dark field miscroscopy.
in bright field the specimen is darker than the surrounding field; and in dark field the specimen is illuminated surrounded by darkness
What does the dark field have that the light field does not?
a dark illumination block and a dark field patch stop
What microscope is best for observing intracellular structures?
phase contrast miscroscope
What does staining do for the microscopic view?
it changes the amplitude and wavelength
What are three components specific to the flourescent microscope?
emission filter, excitation filter, and dichroic mirror
Which mircoscope is most useful in diagnosing infections?
What microscope would you use to look at fimbriae or viruses?
electron miscroscope and flourescent miscroscope
What are some characteristics of prokaryotes?
single chromosome, no nuclear envelope, no membrane bound organelles, have cell wall with peptidoglycan, no carbohydrates or sterols, 70s ribosome, and average size of 0.2-2um
What are some characteristics of eukaryotes?
multiple chromosome, membrane bound nucleus and organelles, cell wall only in plants, no peptidoglycan, has sterols and carbohydrates, 80s ribosome, and average size of 10-100um
True or False: Outside the eukaryotic cell is more complicated but inside the prokaryotic cell is more complicated.
False; outside the prokaryotic cell is more complicated and inside the eukaryotic cell is more complicated
What is the difference between staphylococcus and streptococcus?
they are both cocci (spherical) however streptococcus are cocci attached linearly and staphylococcus are cocci attached in a cluster
What is a micoplasma?
a genus of bacteria that lack a cell wall making them unaffected by many common antibiotics
What does the slelective cytoplasmic membranse allow to pass?
small molecules like H2O, O2, and CO2
What are the targets for disinfectancts on the cytoplasmic membrane?
What are the targets for antibiotics on the cytoplasmic membrane?
What are some inhibitors of cell wall synthesis?
penicillins, bacitracin, cephalosporinsm and vancomycin
Where does penicillin interfere in the petidoglycan structure?
the cross linkage of the tetrapeptides
What part of the cell envelop determines the gram stain?
the cell wall which contains the peptidoglycan layer
Describe the peptidoglycan composition.
it consists of a repeating NAM-NAG backbone in which peptide chains attach NAM fragments together, forming cross links between the backbones
What kind of bacteria is lipoteichoic acid found in?
gram positive bacteria
What kind of bacteria is lipopolysaccharide found in?
gram negative bacteria
What type of bateria has a large peptidoglycan layer and therefore stains purple?
What is the outer membrane (LSP) of gram positive bacteria composed of?
lipid A (for biological activity), a core polysaccharide, and an oligosaccharide/O-antigen (for antigenicity)
Which type of bacteria is more susceptible to penicillin?
Where is the periplasmic space in gram negative bacteria?
between the outer membrane and the cytoplasmic membrane
What do you stain mycobacterium with?
What are the cytoplasmic structures of bacteria?
ribosomes, spores, and nuclear material
What are plasmids?
extrachromosomal DNA; small version of chromosomes that carry DNA, but not require for growth
What kind of DNA does bacteria have?
What is the site of proteins synthesis and action for antibodies?
Describe the prokaryotic ribosome?
16s rRNA makes up the 30S subunit which comes together with the 50S subunit to form the 70S ribosomal complex
Describe the eukaryotic ribosome?
18s rRNA makes up the 40S subunit which comes together with the 60S subunit to form the 80S ribosomal complex
What are metachromatic granules?
a type of bacterial inclusion that stains red with methylene blue
What does it mean to say that the bacteria is in a vegetative state?
the cell does not contain a spore
What are the components of the external structures of the cell and what are their functions?
capsule: fight against the immune system
pili: attachment (F- if not sex pili, and F+ if ther is a sex pili)
What is glycocalyx?
a sugar coat synthesized by the cell
How do you perform stereotyping based on the flagella?
the H antigen
Descibe the four types of flagella?
polar: one on one end
lopotrichous: several on one end
peritrichous: several spread all over
amphitrichous: extending from both ends
What is taxis?
a stimulus that attracts or repels chemitaxis of phototaxis
True or False: Fimbriae and pili can form both inside and out of the cell.
What is different about fimbriae and pili?
fimbriae can have few to hundres and distributed all over the cell; pili only form one to two per cell and can be involved in DNA transfer
What type of charge do basic dyes have?
basic dyes are cationic with positive charges on the chromophore
What type of charge do acidic dyes have?
acidic dyes are anionic with negative charges on the chromophore
Why are basic dyes mostly used on bacteria?
because bacteria a negatively charged and basic dyes have a positive charge
What are some basic dyes?
crystal light, methylene blue, malachite green, and safranin
What is negative staining?
the microbe repels the dye and the dye stains the background
What is a differential stain?
use a primary stain and a counter stain to distinguish the cell types or parts (ex gram stain and acid fast)
What method allows for examination of characteristics of live cells for motility, shap, and arrangement?
wet mounts and hanging drop mounts
What is a fixed mount?
made by drying and heating a film of specimen
What is the purpose of an acid-fast stain?
differentiates bacteria into acid-fast or non acid-fast based on the presence of mycolic acid (waxt coat); used in the diagnosis of mycobacterial infections
What is inoculation?
when the sample is placed on sterile medium providing microbes with the appropriate nutrients to sustain growth
True or False: The isolation process produces the culture.
False; the incubation process produces the culture
How should serum for serological tests be kept?
at -20 to -80 freezer
What is bacterial growth?
an increase in number of cells, not size, via binary fussion
What is generation time?
the time it takes for the cell to divide into two (doubling time); usually about 1-3 hours
What are some extreme examples to generation time?
Escherichia coli takes 20 minutes
Mycobacterium tuberculosis takes 24 hours
What is the lag phase?
the bacteria is first encountering a new environment and becoming metabolically active; very little change in the number of cells
What is the log phase?
there is rapid growth of the bacteria
What is the stationary phase?
the amount of growth equals the amount of death due to environmental stress; competition for nutrients and space
What is the death phase?
when the death rate is greater than the rate of reproduction; usually due to limitted factors in the environment
What is chemically defined media?
(synthetic) the exact chemical composition is known and it is used to grow fastidious organisms
What is complex media?
(non-synthetic) the exact chemical composition is not known and most bacteria and fungi are grown with this
What is general purpose medium?
media that grows a broad range of microbes; usually non synthetic
What is enriched medium?
contains complex organic substances such as blood, serum, hemoglobin or special growth factors required by fastidious microbes
What are fastidious bacteria?
organisms that require specialized environements due to complex nutritional requirements
What is selective medium?
media that suppresses growth of unwanted bacteria and promotes growth of desired bacteria
What is differential medium?
media that differentiates two or more types of bacteria; generally a solid medium
What is selective and differential medium?
allows the growth of specific groups of pathogens, and display visible difference between the growing bacteria
What temperatures do psychrophiles live in? mesophiles? thermophiles?
psychrophiles = 0-20 degrees C
mesophiles = 20-40 degrees C
thermophiles = 40-100 degrees C
Which temperature classification of bacteria (psychrophiles, mesophiles, or thermophiles) are food bourne pathogens?
What is the optimal physiological pH for most bacteria?
pH 6.5 - pH 7.5
What reaction does catalase catalyze?
2H2O2 --> 2H2O + O2
What reaction does peroxidase catalyze?
H2O2 + NADH + H --> 2H2O + NAD
What reaction does superoxidase dismutase catalyze?
2O2 + H2 --> H2O2 + O2
What is the difference between aerotolerant anaerobes and facultative anaerobes?
aerotolerant anaerobes do anaerobic respiration but are not killed by oxygen, however facultative anaerobes can perform aerobic and anaerobic respiration
What are microaerophilic bacteria?
bacteria that grow under low oxygen conditions, are killed by high oxygen levels, and perform aerobic resiration
What are capnophiles and carboxyphiles?
bacteria that require more than atmospheric CO2
What is metabolism?
the sum total of all the chemical processes that occur in a living cell, beginning with nutrients brought in from the external environment and cultivating in the production of a new cell
What is catabolism?
degradative process that breaks down larger molecules and forms smaller molecules releasing energy
What is anabolism?
the biosynthesis process that forms larger macromolecules from smaller ones requiring energy input
What is diffusion?
the passage of molecules through the membrane with out the expenditure of energy
What is simple diffusion?
movement occurs with concentration gradient without the help of carrier proteins
What is facilitated diffusion?
carrier proteins bind and transport molecules across the cell membrane
What two reactions generate energy?
oxidation-reduction reactions and phosphorylation (mainly of ATP)
In fermentation, who is the final electron acceptor? In aerobic respiration? In anaerobic respiration?
in fermentation, organic compounds are the final electron acceptors; in aerobic respiration, oxygen is the final electron acceptor; and in anaerobic respiration, non oxygen electron acceptors (SO4, NO2, NO3, and CO2)
What is the difference between sustrate-level phosphorylation and oxidative phosphorylation?
oxidative phosphorylation converts NADH to NAD and O2 to H2O while phosphorylating ADP to ATP;
substrate-level phosphorylation uses organic compounds and phosohoglycerate kinase to phosphorylate ADP to ATP; basically oxidative uses professional electron carriers (NAD and FAD) and SLP uses any substrate
COMPLETE destruction of microorganisms via heat, radiation, chemicals, or physical removal
reduction of growth on non-living surfaces
reduction of growth on living tissues
What is the difference between the suffix -cidal and -static?
-cidal means to kill the microbe
-static does not kill but inhibits microbial growth
What are some factors effecting antimicrobial growth?
number of bacteria, concentration of antimicrobrial agents, environemtal conditions, time of exposure, and microbial characteristics
What are the three physical methods of sanitation?
heat, radiation, and filtration
How would you conduct hot air sterilization?
put the material in an oven at 170 C for 2 hours
How would you conduct moist heat boiling sanitation? and what is it not effective against?
boil the material at 100 C for 10-15 minutes
this is not effective against endospores and some viruses
What is pasturization?
disinfection for heat sensitive liquids; intended to kill pathogens and lower bacterial numbers in order to prolong the shelf life
Desribe the three phases of heat paturization.
slow heat = 63 C for 30 minutes
high temp/short time = 72 C for 15 minutes
ultra high temp (UHT) = 140 C for 3 sec
What is the pore size of membrane filters?
0.22 - 0.45 um
What is the wavelength for ionizing radiation? for non-ionizing?
ionizing = <1nm
non-ionizing = >1nm
When is ionizing radiation used?
used on substances that could be damaged by heat
When is non-ionizing radiation used?
when cleaning surfaces
UV rays are non-ionizing radiation, how does it work?
UV rays have a wavelength of 220 to 300nm which is damages DNA by causing bonds to form between thymine
True or False: Generally chemicals do not achieve sterility, but reduce bacterial numbers.
What is significant about phenol as a chemical sanitizer?
it was the first chemical to be used and works to disrupt the cytoplasmic membrane
What are the standard drugs used in the phenol coefficient?
salmonella typhi and staphylococcus aureus
How do alcohols sanitize?
denature proteins and disrupts cytoplasmic membrans by dissolving lipid; effective at 60-90%
What are quaternary ammonium compounds?
cationic detergents mostly used as surface active agents for mainy gram positive
What percent of formaldehyde is formalin?
What is a gene?
a DNA sequence that encodes for a specific product
What is a genome?
all genes taken together within an organism
What is the difference between an exon and an intron?
an exon is the segment of the gene that contains a coding sequence and and intron is the non coding sequence that separates exons
What is an allele?
different forms of the same gene
What are the components of a nucleotide? a nucleoside?
nucleotide = phosphate group, pentose sugar, and a nitrogenous base
nucleoside = just the pentose sugar and nitrogenous base
Describe the bond between phosphate group and pentose sugar of DNA?
the phosphate group attaches to the 3' carbon of one sugar and the 5' carbon of another via covalent bonds
What type of bonds to the base pairs have?
What is the difference between topoisomerase I and II?
topoisomerase I is DNA gyrase which introduces the negative strand and topoisomerase II removes supercoiling
What is transcription?
one strand of DNA is used as a template to from a complimentary of mRNA
How many possible combinations of base codes for amino acids are there?
What does nitrous acid do to base pairing?
causes adenine to change so that it pairs with cytosine instead of thymine
What is genetic transformation?
the incorporation of free (naked) DNA into a recipient cell
What is conjugation?
one bacterium passes some DNA (in a plasmid) to another bacterium via a sex pilus
What is the difference between generalized transduction and specialized transduction?
in generalized transduction nucleic acid from any portion of the host genome is transferred; and in specialized transduction nucleic acid only comes from a specific region of the host genome
How do you conduct a moist heat autoclave?
under steam pressure of 121 C for 15 minutes, using indicators
True or False: Prokaryotes have introns and exons but eukaryotes only have exons.
False; eukaryotes have both introns and exons and prokaryotes only have exons
What is the phosphodiester linkage in DNA?
between the pentose surgars, the phosphate group that connects the two sugars
What is the purpose of an RNA primer and DNA ligase?
these are only on the lagging strand; the primer allows the start of replication on the lagging strand and the ligase connects the sections together
What is a silent mutation?
a change in the third base pair that does not effect the overall type of amino acid or its function
What is a mis-sense mutation?
a change in the first or second base pair that causes a the sequence to code for a different amino acid
What is a non-sense mutation?
a change in the third base pair that causes the sequence to code for a stop codon, terminating protein synthesis