LO topic 3c - d Flashcards
List the major types of mutations (point, insertion, deletion, inversion, and translocation)
Point - occurs in a genome when a single base pair is added, deleted or changed (insertion, deletion, inversion and translocation)
Insertion - Occurs when one or more new nucleotide pairs are inserted into the DNA double helix.
Deletion - Occurs when one or more nucleotide pairs are removed from the double helix.
Inversion - Occurs when a piece of DNA is cut out
of a chromosome, turned around, and re-inserted into the gap.
Translocation - Occurs when a chunk of DNA (often very large) is removed from one chromosome and attached to another.
Describe how gene expression is regulated in prokaryotes and eukaryote
Prokaryotes regulate gene expression through operons
In eukaryotes the gene expression is regulated through a multi level process of transcription and translation
Gene Expression is regulated and occurs at the level of transcription, translation, or protein actively. Not that not all genes are phenotypes.
Be familiar with the terms operon, regulatory gene, promoter, operator and structural genes.
Operon - Bacterial DNA is organised into units called operons, which contain functionally related genes. They consists of four parts:
Regulatory gene (timing of transcription),
Promotor (site of initial transcription) ,
Operator (access of RNA)
Structural genes (encodes enzymes and proteins)
Describe how bacteria can acquire DNA from the environment and how viruses transmit pieces of DNA between organisms. Be familiar with the terms, transformation and plasmid.
Transformation - bacteria picks up DNA from the environment This DNA could be part of a chromosome from another bacterium or tiny circular DNA molecules called plasmids
Plasmid - a small, circular, double-stranded DNA molecule that is distinct from a cell’s chromosomal DNA
Describe the basic process of DNA amplification by polymerase chain reaction (PCR) and the separation of gene products with gel electrophoresis, and how these techniques are used in forensic science
Polymerase chain reaction (PCR) - through first synthesising primers (DNA strands) then reacting to multiply copies of DNA
Gel electrophoresis - DNA is negatively charged so as the current moves the DNA separates into fragments, special nylon paper current moves them onto it. Paper is then bathed in DNA probes which reveals their location.
Used in DNA analysis for possible phenotype profiles
Explain the process whereby foreign genes are introduced into the genome of a target organism to make a genetically modified organism (GMO), and list some traits that have been successfully introduced into crop plants using these methods.
Three major steps (isolate gene, clone, insert clone)
Isolation is done through either chromosomes (gene donor) or gel electrophoresis (DNA fragment separation)
Cloned genes done by inserting the gene into a bacterial plasmid which then replicate as the plasmid multiples
Insertion where the plasmid is cut open an the gene is inserted with sticky ends which bonds with DNA ligase
This process is used for IVF and genetic engineering
