Chapter 11: Biotechnology Flashcards
What is recombinant DNA (rDNA)?
DNA altered to contain nucleotides from two different organisms.
What is a genetically modified organism (GMO)?
An organism expressing a new gene introduced through genetic modification.
What is the most commonly used bacterium in genetic engineering?
Escherichia coli (E. coli).
What are the general steps of gene transfer?
Identify the gene → Amplify via PCR → Insert into vector → Transfer to cells → Identify & clone modified cells.
What are common vectors used in gene transfer?
Plasmids, viruses, and liposomes.
What are the main enzymes used in gene transfer?
Restriction endonucleases, ligase, and reverse transcriptase.
What do restriction endonucleases do?
Cut DNA at specific sequences.
What is the function of DNA ligase in genetic engineering?
Joins DNA fragments by linking their sticky ends.
Where is most of E. coli’s genetic information stored?
In a single chromosome.
What is a plasmid?
A small, circular DNA molecule separate from the bacterial chromosome.
Why are plasmids important in cloning?
They act as vectors to transfer foreign genes into bacteria.
What is a recombinant plasmid?
A plasmid containing an inserted foreign gene.
Which enzyme is used to convert mRNA into DNA?
Reverse transcriptase.
What is the role of DNA polymerase in insulin production?
Converts single-stranded DNA to double-stranded DNA.
What are transgenic plants?
Plants with introduced foreign genes for desirable traits.
What is an example of transgenic animal use in medicine?
Transgenic sheep producing factor IX for hemophilia treatment.
What technique is used to separate molecules like proteins and DNA?
Gel electrophoresis.
What factors affect molecule movement in gel electrophoresis?
Net charge, size, and gel composition.
Why do DNA fragments move in electrophoresis?
Due to their negatively charged phosphate groups.
What is DNA profiling?
Matching an unknown DNA sample to a known one.
What is PCR used for?
Rapidly producing a large number of DNA copies.
What are the three main steps of PCR?
Denaturation, annealing, and extension.
What is the purpose of a primer in PCR?
It starts DNA synthesis.
What is gene sequencing?
Identifying all bases in an organism’s genome.
Which technique is commonly used for gene sequencing?
Sanger sequencing.
What does the Sanger technique involve?
Fragmenting DNA, copying fragments, and reading base sequences.
What is a clone?
A group of genetically identical organisms or cells.
How can animals be cloned from embryos?
By separating embryonic cells and implanting them into a uterus.
How was Dolly the sheep cloned?
Using the nucleus from an adult cell fused with an enucleated egg cell.
What was a key finding from Dolly’s cloning?
Differentiated cells can be used to create a clone.
What is a microarray?
A tool used to analyze gene expression and genome composition.
How do microarrays detect gene expression?
By hybridizing cDNA to DNA probes on a chip.
Which enzyme is used to convert mRNA to cDNA in microarrays?
Reverse transcriptase.
What is a key application of microarrays?
Comparing gene expression in cancer vs. normal cells.
What happens if a DNA sample does not bind to a microarray probe?
The gene is absent in that sample.
What does fluorescence in a microarray indicate?
Hybridization of cDNA to a complementary DNA probe.
What is the purpose of gel electrophoresis in diagnosing sickle cell anemia?
To separate hemoglobin variants based on charge differences.
What is the function of a buffer solution in PCR?
Maintains pH and stabilizes enzymes.
Why is PCR useful in forensic science?
It amplifies small DNA samples for analysis.
What role does a DNA polymerase play in PCR?
It synthesizes new DNA strands.
What kind of charge do proteins typically have in electrophoresis?
A net negative charge.
What is the main component of the gel used in electrophoresis?
Agarose.
Why do smaller DNA fragments move faster in gel electrophoresis?
They experience less resistance in the gel.
What are sticky ends in genetic engineering?
Overhanging sequences left after restriction enzyme cuts.
What is an application of DNA profiling?
Paternity testing.
What is a practical use of genetically modified crops?
Pest resistance.
Why is E. coli commonly used in genetic engineering?
It grows rapidly and its genetics are well understood.
How does electrophoresis separate sickle cell hemoglobin from normal hemoglobin?
They have different charges and migrate differently in the gel.
What is the first step in cloning a gene?
Identifying and isolating the gene.
How does PCR achieve exponential DNA amplification?
Each cycle doubles the number of DNA copies.
What happens if a PCR primer does not match the DNA template?
DNA replication will not occur.
What is the advantage of using cDNA in microarrays?
It represents actively expressed genes.
Why is a fluorescent dye used in microarrays?
To visualize hybridization of DNA samples.
Why do restriction enzymes cut at specific sites?
They recognize particular base sequences.
How do scientists identify transformed cells in gene transfer?
By using marker genes for selection.
What is a key advantage of microarrays?
They allow simultaneous analysis of thousands of genes.
What does a microarray measure?
Gene expression levels.
What is a DNA probe in a microarray?
A single-stranded DNA sequence that binds complementary sequences.
What is a major application of DNA sequencing?
Identifying mutations linked to diseases.
What does Sanger sequencing use to terminate DNA synthesis?
Dideoxynucleotides (ddNTPs).
What is an alternative to Sanger sequencing for whole-genome sequencing?
Next-generation sequencing (NGS).
Why is DNA sequencing important in medicine?
It helps diagnose genetic disorders.
What are the steps of cloning an organism?
Isolate DNA → Insert into vector → Introduce to host → Select clones.
What is a common method for inserting DNA into bacterial cells?
Transformation using plasmids.
What ethical concerns exist around human cloning?
Issues of identity, consent, and genetic modification.
Why is cDNA used instead of mRNA in microarrays?
cDNA is more stable and easier to analyze.
What role do fluorescent tags play in DNA sequencing?
They label bases to identify the sequence.
What is one use of cloned animals in research?
Studying genetic diseases.
Why is gel electrophoresis used before sequencing?
To check the quality and size of DNA fragments.
