Biotech Final Exam Study Guide Latest Update 2024-2025 250 Questions and 100% Verified Correct Answers Guaranteed A+
How are monoclonal antibodies produced? - CORRECT ANSWER: 1) target protein
inject into immunosuppressed mouse 2) isolate B cells 3) fuse B cells to cultured myeloma cells to extend life of B cell (hybridomas formed) 4) hybridomas spread on growth plate and screened for antibody production 5) antibody-producing hybridomas cloned 6) pick best monoclonal patch for treatment and isolate monoclonal antibodies 7) inject monoclonal antibodies into patient
How are polyclonal antibodies produced? Why can they not be used as therapeutic
agents? - CORRECT ANSWER: 1) target protein introduced into animal (rabbit)
2) rabbit makes antibodies against target molecule (polyclonal, binding to different parts of target molecule) 3) antibodies purified polyclonal antibodies vary in effectiveness for each batch
How can you control the particle penetration when using a gene gun? - CORRECT
ANSWER: - varying intensity of the shot
- alter the distance particles travel to reach target cells
- different sized particles
How can you minimize metabolic load? - CORRECT ANSWER: - use low copy #
plasmids
- incorporate target gene into host genome
- regulatable promoters
- moderate target protein expression and cell density
How can you target chloroplasts during plant transgenesis? - CORRECT ANSWER: 1)
gene gun to shoot plasmid with gene into chloroplast (DNA) 2) Fusion gene that directs transport of protein to chloroplast and is cleaved off (protein)
How can you use the embryonic stem cell method to produce a knock-out mouse? -
CORRECT ANSWER: use a selectable marker as your transgene
- design the plasmid to integrate in the coding region of a gene
- allows you to study the consequences of inactivating that interrupted gene
How do vaccines work? - CORRECT ANSWER: part or whole pathogen given to
stimulate immune system against infection by that pathogen
- makes antibodies and B memory cells
- stockpile of antibodies and memory cells for faster reaction
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How do you change media for adherent cells and suspension cells? - CORRECT
ANSWER: adherent = media removed by aspiration and replaced
suspension = centrifugation to separate then resuspension in fresh media
How do you increase the chances of your plasmid attaching to target DNA instead of
itself? - CORRECT ANSWER: - 10-fold more target DNA
- alkaline phosphatase to remove 5' phosphate groups
How do you preserve proteins in downstream processing? - CORRECT ANSWER: -
lyphilization (freeze drying) (liquid protein frozen then vacuumed to evaporate water from fluid)
How do you screen your genomic library? - CORRECT ANSWER: membrane
hybridization assay
- transfer the colonies with each fragment to a membrane
- lysis bacterial cells and denature DNA
- clone that binds radioactive probe produces a spot on autoradiogram
Immunological assay - tests for presence of protein product with primary and secondary antibody
How do you select for the plants that took up both plasmids during chloroplast engineering? - CORRECT ANSWER: 1) incubate in antibiotic to get rid of those without selectable marker 2) expression tests to isolate plants that express gene of interest
How does the DNA get into the chloroplast genome? - CORRECT ANSWER:
homologous recombination using 2 plasmids
- one plasmid with selectable marker flanked by DNA from one region of chloroplast
- other plasmid with gene of interest flanked by DNA from different region of chloroplast
DNA
genome BOTH have promoter to allow transcription ONLY in chloroplast
How does the nomenclature for restriction enzymes work? - CORRECT ANSWER: First
letter = genus of organism it came from second and third = species of organism it came from fourth = strain Roman numeral = number it came from the organism
Leaf Fragment: How do you introduce the Ti plasmid with your recombinant DNA into
Agrobacter? - CORRECT ANSWER: same methods used for E. coli
- both cloning vector and helper plasmid introduced into Agobacter
- select for bacteria that have both plasmids
Leaf fragment: Producing Recombinant DNA 2 / 4
What 4 things do Ti plasmids need? - CORRECT ANSWER: 1) selectable marker
genes for plant, E coli, and Agrobacter 2) origin of replication for E coli and one for Agrobacter 3) vir genes ( may be provided with helper plasmid) 4) cloning site - site where gene of interest can be inserted in place of T-DNA
Leaf fragment: Producing Recombinant DNA
What is a 2-plasmid system? - CORRECT ANSWER: one plasmid has gene of interest,
selectable markers, and origins helper plasmid has only vir genes
Leaf Fragment: Which plants can be cultured with Agrobacter? How does the
Agrobacter get into the plant? What causes the vir genes to be expressed? - CORRECT
ANSWER: only dicots
- tomatoes, potatoes, apples, grapes, etc.
- Agrobacter attaches to leaf fragments and enters through breaches in ell wall
- chemicals from wounded leaf cause vir gene expression
NOT corn or wheat
pBR322 Cloning: How is selection accomplished with a pBR322 plasmid? - CORRECT
ANSWER: 1) bacteria on Amp plates (non-transformed cells will die since they don't have the Ampr gene from pBR322) 2) sterile velvet used to make replica plate on Tet plates (cells with recombinant DNA) (transformed colonies will die since their Tetr gene is broken) 3) cultures of cells from Amp plate that were missing from Tet plate (missing colonies are the transformed colonies)
pBR322 Cloning: What are the steps for creating the recombinant DNA? - CORRECT
ANSWER: 1) pBR322 cut with restriction enzyme that cuts within Tetr gene
- produced DNA fragment with sticky ends
2) pBR322 fragment combined with target DNA cut with same enzyme (same sticky ends) 3) mixture treated with ligase
What 2 categories of microorganisms used for biotech? - CORRECT ANSWER: -
Provide genes for specific functions
Ex: genes encoding heat resistant DNA polymerases used in PCR isolated from
thermophiles and cloned into E. coli
- Genetically engineered to perform task more effectively
Ex: Corynebecterium glutamicum a gram-positive, non pathogenic and fast growing soil bacterium engineered to improve amino acid yields
What are 3 reasons for producing transgenic plants? - CORRECT ANSWER: 1)
improves value of plant (agriculture, horticulture, ornamental) 2) living bioreactor for production of important proteins 3) study action of genes during development and other biological processes 3 / 4
What are chemically-linked monoclonal antibodies? Why are these a good thing? -
CORRECT ANSWER: monoclonal antibodies that allow for the delivery of
drugs/enzymes to the site where they need to work
- this can reduce side effects
What are chemiluminescent detection procedures? What is an example? - CORRECT
ANSWER: method for diagnostics using fluorescence to avoid radioactive probe
Ex:1) biotin labeled target DNA
2) streptavidin added and binds to biotin 3) biotin labeled alkaline phosphatase added and binds to streptavidin 4) alkaline phosphatase turns colorless substrate blue
What are considerations for scaling up protein production in downstream processing? -
CORRECT ANSWER: - usually first designed on small-scale
- small-scale methods may not work on large scale
- FDA reapproval might be needed
- bioprocess engineers involved in upstream to help downstream methods early on
What are immunological diagnostic procedures based on? What is the most common method? What are some applications of immunological diagnostic procedures? -
CORRECT ANSWER: identifying specific antibody-antigen complex
- Enzyme-Linked Immunosorbent Assay (ELISA)
-drug testing, monitoring cancer, detection of metabolites, pathogen identification
What are molecular diagnostics designed to do? what are their characteristics (hint: 3
S's)? - CORRECT ANSWER: use either immunological or DNA detection procedures
- specific
- sensitive
- simple
What are possible applications for plant biotechnology? What are examples? -
CORRECT ANSWER: - antisense (flavr savr)
- vaccines for plants (Tobacco mosaic virus vaccine engineered to have protein from
- genetic pesticides (GE plants to produce Bt toxin against insects and larvae)
- herbicide resistance (GE resistance to glyphosphate, a common herbicide)
- enhanced nutrition (golden rice GE to contain gene for provitamin that converts to
surface of TMV)
vitamin A, came from daffodils)
What are primary cells? - CORRECT ANSWER: cells cultured directly from the subject
What are some examples of DNA diagnostic probes for diseases? - CORRECT
ANSWER: - probes designed to detect plasmodium that causes Malaria
- probes that detect Salmonella or other bacteria
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