DAT biology- microscopy and lab techniques
restriction fragment length polymorphisms (RFLPs) and short tandem repeats (STRs) are used in ___ which is a technique that may be used in paternity and forensic cases
DNA fingerprinting
PCR can be carried out in a single container- list the components that container needs to contain in order for PCR to take place
DNA to be cloned, nucleotides, DNA, primers, heat-resistance DNA polymerase (Taq polymerase)
___ is a condition that results in a third copy of chromosome 21 and ___ allows for substantiation of its diagnosis
Down syndrome (trisomy 21), karyotyping
is SEM or TEM used to look at surfaces
SEM
describe the general idea of a pulse chase experiment for proteins
add radioactive aa during the pulse -> radioactive protein synthesis -> wash away radioactive aa -> add regular aa during the chase
southern and northern blotting tend to use ___ gel whereas western blotting tends to use ___
agarose, SDS-PAGE
what are 2 pep methods for selecting bacterial cells that have. undergone transformation in bacterial cloning
antibiotic resistance and color change
ELISA is based on the idea that a person will have ____ for a given diseases ___ of they have the disease or have been exposed to it
antibodies, antigens
___ are less common than sticky ends and they do not have unpaired nucleotides
blunt ends (harder to hybridize bc of the paired nucleotides)
what are some advantages of electron tomography?
can look at objects and their relative positions in 3D
what are hemocytometers
cell counting chambers
___ is the process where cell contents are separated into their fractions ( one part of a whole) by centrifugation
cell fractionation
gel electrophoresis separates macromolecular fragments on their ___ and ___
charge and size
colony forming units are based on the assumption that each viable cell initially plated gave rise to a ___
colony
___ are used to estimate the number of cells plated on a growth medium
colony forming units
what are some adv of confocal laser scanning optical microscopy
colorful, 2D image of living cells, view chromosomes during mitosis, overcomes fluorescence distortions (higher resolution)
what are some adv of fluorescence optical microscopy
colorful, 2D images of thin samples of living cells, inc brightness
___ is DNA made from RNA and to is used in microarrays and bacterial cloning
complementary DNA (cDNA)
___ are light microscopes that focus visible light to produce a 2D image of thin samples (single cell layers)
compound microscopes
___ is like SEM but the sample is frozen instead of dehydrated
cryo-scanning electron microscopy
in ___ only scattered light from the sample is transmitted to produce 2D images of unstained living cells
dark field optical microscopy
what are the 3 cyclical steps of PCR
denaturation, primer annealing, elongation
___ centrifugation separates cell contents in just 1 spin step creating multiple layers separated by density
density
____ is an older and more established method of DNA sequencing, while _____ is used more often now because it is quicker and cheaper
dideoxy chain termination (Sanger sequencing); next generation sequencing
what are the 2 most common method for DNA sequencing
dideoxycytidine chain termination (sanger sequencing) and next generation sequencing
in ___ cells are split open w a blender and the resulting homogenate is separated based on mass, density and or shape
differential centrifugation
what are the 3 germ layers from superficial to most deep
ectoderm, mesoderm, endoderm
what are 2 methods for automated cell counting
electrical resistance and flow cytometry
most viruses are so small that they mist be viewed using ___ microscopy
electron
___ integrates multiple TEM 2D images into a 3D model
electron tomography
___ microscopy allows for higher magnification than ___ microscopy
electron, optical
___ is a process where electricity is applied to cells creating temporary holes in the plasma membrane
electroporation
___ is a technology to determine if a specific antigen exists in a person, aiding in the diagnoses/exposure to certain diseases
enzyme-linked immunosorbent assay (ELISA)
bacterial cloning is an important technique to produce medicines bc ___ are cloned in ___
eukaryotic gene products, prokaryotic cells (insulin gene is obtained as cDNA from processed human mRNA
what is an advantage of dark field optical microscopy?
excellent contrast on living samples of unstained cells (black background)
microscope_____ adheres cells two microscope slides in their most lifelike state, and makes it easier for those cells to be stained
fixation, stained
in ___ cells pass through a very narrow tube and can be counted via detection by a laser beam
flow cytometry
___ is the emission of photons (light) from a particle that has absorbed light
fluorescence
___ provides a quantitive measure of the concentration of various ions, molecules. and gases in a cell
fluorescence lifetime imaging microscopy (FILM)
___ gives quantitive insights into cell dynamics bc bimolecular movements in live cells can be traced
fluorescence recovery after photobleaching (FRAP)
what are some disadvantages of fluorescence optical microscopy
fluorescence sometimes create distortions that reduce resolution
___ and ___ are optical microscope techniques that use laser light to produce 2D images of samples that have been tagged with fluorophores
fluorescences, confocal laser scanning
___ refers to the amount of time it takes for an excited molecule to release all its fluorescence
fluorescent lifetime
___ are fluorescent chemicals that will reemit light upon being excited by another light source
fluorophores
a ___ is a way to store all the DNA of an organisms genome
genomic library
___ studies all the genes of a genome by looking at their structure and function as well as their interactions with each other
genomics
what are some advantages of phase-contrast optical microscopes?
good resolution and contrast, can be used to observe thin samples of living cells- including their internal structure
what are some advantages of TEM?
high resolution 2D images of internal sample structures
what is an advantage of SEM
high resolution, 3D images of sample surfaces
what are some advantages of cryo-SEM?
high resolution, 3D images of sample surfaces, which are presented in a more natural form than SEM (due to freezing)
what are some disadvantages of phase contrast optical microscopes
ineffective on thick samples, halo effect around sample edges
what are some disadvantages of electron tomography?
it is costly and the extensive preparation kills all living cells
what are some disadvantages of TEM?
it is costly and the extensive sample preparation kills all living cells
what are some disadvantages of cryo-SEM?
it is costly and the fixation, staining, freezing kills the sample
what are some disadvantages of SEM
it is costly, and the fixation/staining/dehydration kills the sample
___ is the observation of chromosomes under a light microscope using staining
karyotyping
fixation and staining are associated w cells that have been _____
killed
compound light microscopes usually have different ___ which gives them the ability to make more resolute images than a stereo/dissection microscope
lens magnification
most optical microscope techniques can be used to view ___ samples of cells
living
describe the process of heat fixation:
living cells are placed on slide-> the slide is passed over a flame to kill/glue the cells to the slide -> stain is applied
what is an disadvantage of dark field optical microscopy?
low light intensity
centrifugation separates cell components through ___
mass, density and or shape
karyotyping is performed during ___
metaphase
a ___ is a chip containing thousands of probes that are complementary to a certain sequence
microarray
____ cells can give rise to some of the 3 germ layers but not all so their are the most differentiated and cannot develop an entire organism
multipotent
can electrons microscopy be used to look at living specimens?
no due to fixation and staining
___ is an electrophoresis technique for separating RNA fragments and is used ___ probes
northern blotting, RNA
arrange the following organelles from most to least dense: ER, ribosomes , mito, nuclei, chloroplasts
nuclei > mito/chloroplast > ER > fragments > ribosomes
as cells show electrical resistance and impede conductance the ___ in a solution can be estimated by observing the flow of electricity
number of cells
a karyotype shows both the ___ of chromosomes and their ___
number, physical appearances
a ___ occurs when there is a black of nucleotides that are inverted mirrors of each other
palindromic sequence
___ are optical microscopes that use light phase changes and contrast to produce 2D image of thin sample
phase-contrast microscopes
___ catalyzes phosphodiester bonds bw the ends of DNA restriction fragments (used heavily in genomic libraries and bacterial cloning)
plasmids
a ___ cell can give rise to an of the 3 germ layer but they cannot develop and entire organism bc they can't develop extra embryonic tissue
pluripotent
the ___ is an automated biotechnology process that can quickly create millions of copies of DNA and it requires no cell
polymerase chain reaction (PCR)
a ___ is a fluorescent or radioactively labeled tool that allows scientists to identify a specific sequence within a large sample
probe
___ corresponds to a eukaryotic gene with all intros removed (used in microarrays and bacterial cloning)
processed mRNA
centrifugation can be used to separate ___ based on solubility
proteins (insoluble proteins pellet out while the soluble proteins remain in the supernatant)
___ experiments allow for the visualization/tracking of molecules of interest throughout a cell
pulse chase
___ is produced when DNA fragments from different sources are joined together
recombinant DNA
knockout mice have a selected gene of interest knocked out by ____
recombinant DNA technology
what are some disadvantages of confocal laser scanning optical microscopy
reduced light intensity and longer illumination times than fluorescences optical microscopy
___ is the process of reverting a multipoint somatic cell to totipotency such that it can develop into another identical animal
reproductive cloning
the DNA fragments that get incorporated into recombinant DNA are produce by ___ which tend to cut DNA at palindromic sequences to produce ___ ends
restriction enzymes, sticky or blunt
___ are unique lengths of DNA that result from restriction enzymes allowing the comparison bw individuals
restriction fragment length polymorphisms (RFLPs)
___ produces complementary DNA (cDNA) from mRNA, and it is relied upon for microarrays and bacterial cloning
reverse transcriptase
what are the 3 components of a chromatography apparatus
sample, mobile phase, stationary phase
___ captures electrons that are scattered by atoms found on the surface of dehydrated samples
scanning electron microscopy (SEM)
in centrifugation the densest and most compact particles will ___ to the bottom of the tube first becoming pressed together as a ____ (precipitate)
sediment, pellet (top liquid is the supernatant)
a ___ is a group of nucleotides that repeats again and again in a stretch of DNA
short tandem repeats (STRs)
for the most part the human genome is the same with slight differences in the sequence every 1000 nucleotides (called ___) which serve as markers for genes that caused disease
single nucleotide polymorphisms (SNPs)
in gel electrophoresis the largest or smallest fragments travel the furthest
smallest
___ is an electrophoresis technique for separating RNA fragments and it uses probes
southern blotting, DNA
___ is the process of adding color to cells which allows them to be viewed more easily under microscope
staining
___ are light microscopes that focus visible light to produce a 2D image of a staples surface
stereo-microscopes (dissection microscope)
what is an advantage of stereo-microscopes/dissection microscopes
they are light microscopes that can be used to view living samples
what is a disadvantage of stereo/dissection microscopes
they are light microscopes that have low resolution
what is an advantage of compound light microscopes
they can be used to view 2D images of living samples (1 cell thick)
what are some disadvantages of compound light microscopes?
they only view samples that are 1 cell thick and they have poor contrast, which means some samples my need to be fixed/stained/killed
___ cells have the ability to produce extra embryonic membranes and ultimately an entire organism
totipotent
___ is a process that occurs when a cells genome is changed by the addition of DNA that was once floating freely in the environment
transformation
competent bacterial cells can undergo ___ and they can be made competent through ___
transformation, electroporation
___ have genes from different species in order to study gene effects and or mass produce medications
transgenic animals
___ capture electrons that are transmitted through a thin slice of a sample
transmission electron microscopy (TEM)
sticky ends have ___ which makes it easy for complementary sticky ends to hybridize
unpaired nucleotides (complimentary sticky ends are made by the same restriction enzymes)
what are some strategies to reduce the halo effect of phase contrast optical microscopy
using phase plates to reduce the phase shift, use thinner samples
in electron microscopy electrons are shot through a ___ at a sample which has been mixed and metal coated (cells are dead)
vacuum (prevents electrons from deviating in path)
a ___ is a piece of DNA (such as a plasmid) that can be taken up by complement cells
vector
___ is an electrophoresis technique for separating proteins and it uses ___ as the probes
western blotting, primary and secondary antibodies