Biotechnology and Genetic Techniques: Key Concepts and Applications

What is biotechnology?

The use of living things to make new products or systems.

Give an early example of biotechnology.

Domestication and the use of microorganisms to produce bread, beer, wine, and cheese.

What is genetic engineering?

Changing the genetic sequence of an organism through modern biotechnology techniques.

What are genetically engineered organisms also called?

Genetically modified organisms (GMOs) or transgenic organisms.

What is the first requirement for DNA modification?

You must be able to make enough copies of DNA to work with.

Why is it necessary to extract and purify DNA?

To prevent parts of cells from interfering with the process.

What are restriction endonucleases?

Enzymes from bacteria that cut DNA at specific sites.

What are restriction sites?

Specific sequences recognized and cut by restriction enzymes.

What are sticky ends in DNA?

DNA ends that are easier to join in the correct orientation after cutting.

What is the role of ligases in genetic engineering?

Enzymes that join (ligate) the sugar-phosphate backbones of DNA fragments.

What is a vector in genetic engineering?

A carrier, such as a bacterial plasmid, that holds a restriction fragment for copying.

What is the polymerase chain reaction (PCR)?

A method of making many copies of a DNA fragment in vitro.

What are primers in PCR?

Short single-stranded DNA fragments that bind to the 5' end of the template.

What temperature is used for denaturation in PCR?

95°C, which separates the DNA strands.

What happens during the annealing phase of PCR?

The reaction is cooled to allow primers to bind to their complementary sequence.

What is gel electrophoresis used for?

To visualize DNA and determine if restriction enzyme digestion or PCR has worked.

How does DNA move in gel electrophoresis?

Negatively charged DNA moves towards the positive electrode, with larger pieces moving more slowly.

What is a DNA-binding dye used for in gel electrophoresis?

To make DNA visible under UV light.

What are gene probes used for?

To search for specific small DNA sequences, such as mutated alleles.

What is cDNA?

Copy DNA synthesized from mRNA through reverse transcription.

What is the significance of next-generation sequencing?

It allows sequencing of a full human genome in five days at a cost of $10,000.

Why are plasmids good for DNA copying?

They can incorporate foreign DNA, are stable, and can replicate within bacteria.

What are selection markers in plasmids?

Genes that confer antibiotic resistance, allowing for selection of bacteria containing plasmids.

What is antibiotic selection?

Growing bacteria in antibiotic-containing media to ensure only cells with plasmids grow.

What is the purpose of using a comb in gel electrophoresis?

To create wells for loading DNA samples into the gel.

What happens to DNA fragments during gel electrophoresis?

They separate into bands according to size, visible under UV light.

What is the role of buffer in gel electrophoresis?

To provide the necessary conditions for DNA to migrate through the gel.

What is the first step in visualizing DNA after gel electrophoresis?

Adding a DNA-binding dye to the gel before applying a current.

What is genetic cloning?

The process of copying DNA using plasmids.

What is the first step in copying DNA using plasmids?

Extracting plasmids from bacterial cells by lysing them.

What is the role of restriction enzymes in genetic cloning?

To cut the plasmid and the DNA fragment to be inserted, creating compatible sticky ends.

What is transformation in genetic engineering?

The process of inserting plasmids into bacterial cells.

How are transformed bacteria selected?

By growing them in antibiotic-containing media.

What is recombinant gene technology used for?

To replace missing or impaired genes in diseases where single genes are affected.

What are vectors in genetic engineering?

Tools that transport DNA from one organism to another.

What is DNA profiling?

A technique that examines short tandem repeats (STRs) and variable nucleotide tandem repeats (VNTRs) to compare genomes.

What are short tandem repeats (STRs)?

Repeats of a short (2-5 bp) sequence in DNA.

What are variable nucleotide tandem repeats (VNTRs)?

Repeats of more than 5 nucleotides in DNA.

What is gene therapy?

A technique used to provide a functional gene to treat genetic diseases.

What is somatic cell gene therapy?

Gene therapy that targets somatic body cells.

What is germline gene therapy?

Gene therapy that transforms egg or sperm cells, affecting future generations.

What is Golden rice genetically engineered to produce?

Beta-carotene, a precursor for vitamin A.

What is Bt cotton engineered for?

To contain genes from Bacillus thuringiensis, which are toxic to certain pests.

What is the purpose of herbicide-resistant crops?

To allow widespread spraying of glyphosate herbicide without harming the crops.

What is cloning?

Making an identical copy of an organism with the same DNA sequence.

What is the process of nuclear transfer in cloning?

Fusing a nucleus from a donor somatic cell into a recipient cell with its nucleus removed.

What are stem cells?

Cells that have not differentiated and can become many different types of cells.

What are pluripotent stem cells?

Stem cells that can become virtually any type of cell in the body.

What ethical questions arise from gene technology?

Questions about the permanence of changes, heritability, and effects on health and ecosystems.

What is a major ethical concern regarding GMOs?

How modifications affect the organism, ecosystem, and consumers.

What is the significance of patenting genes?

It provides financial incentives for companies to develop discoveries but was ruled illegal in 2013.

What is the ethical consideration regarding animal research?

Balancing the need for research insights with animal welfare.

What is the role of genetic testing in health?

To identify alleles responsible for genetic diseases and assist in treatment development.

What mutation causes sickle cell anemia?

A point mutation in the beta-globin gene that deletes a restriction site.

What is the purpose of transgenic organisms in biotechnology?

To produce large quantities of proteins for therapeutic purposes.