Cytogenetics

• Gene expression is the process by which a gene makes a product that is useful to the cell or organism by directing the synthesis of a protein or an RNA molecule.
• The Central Dogma of molecular biology refers to the flow of information from DNA to RNA to protein.
• Transcription is the first stage of gene expression, where DNA is copied into RNA.
• Translation is the second stage of gene expression, where RNA is copied into protein.
• Transcription and translation involve exercises using the genetic code.
• CRISPR - Cas9 has had much success in animal models in the evaluation of genetic basis for thoracic aortic aneurysm and dissection.
• Sickle cell disease is also a candidate condition for the CRISPR - Cas9 therapy.
• Cancer treatment is also being studied using this therapy.
• RNA is used in various types, including Messenger RNA (mRNA), Ribosomal RNAs (rRNAs), Micro RNAs (miRNAs), Transfer RNAs (tRNAs), and Non-coding RNAs (ncRNAs).
• DNA and RNA have different functions.
• The Central Dogma of molecular biology can be illustrated with the help of a flowchart.
• Gene expression involves two stages: Transcription and Translation.
• Transcription and Translation involve exercises using the genetic code.
• Transcription involves the synthesis of RNA from DNA, while Translation involves the synthesis of protein from RNA.
• Non-disjunction is the unequal division of chromosomes during meiosis, where one gamete has two copies of the same chromosome and the other gamete contains zero copy of that chromosome.
• Terms include Euploidy, Aneuploidy, and Polyploidy.
• Aneuploidy is when the chromosome number of the new individual is different from its wild type, typically a result of non-disjunction of chromosomes during mitosis.
• Euploidy is when cells contain a correct and complete set of chromosomes, examples include Monoploidy (x) with one copy of each homolog and Diploidy (2x) with two copies of each homolog.
• Humans are diploid organisms, meaning they have one set of chromosomes from each parent.
• As a result of non-disjunction, offspring have either extra or lost chromosomes, in humans having 47 or 45 chromosomes instead of 46.
• Ploidy refers to the number of sets of chromosomes in a cell.
• The naming of aneuploid conditions is based on the chromosome number added or deleted, for example, Monosomy (2n - 1) refers to the lack of one chromosome of the normal complement.
• Genetic testing and newborn screening tests are applications of DNA technology.
• Gene therapy includes invasiveness of gene therapy sites, somatic gene therapy targets, and gene therapy for ADA, Adenosine Deaminase Deficiency.
• Recombinant DNA technology includes recombinant DNA and its applications such as transgenic organisms, gene silencing and genome editing, and gene therapy.
• Transgenic organisms include transgenic animals and animal models.
• Recombinant DNA comes from more than one type of organism because of the universality of the genetic code.
• Gene therapy includes somatic gene therapy targets and Adenosine Deaminase Deficiency (ADA, Adenosine Deaminase Deficiency).
• Genetic testing and newborn screening tests include Newborn Screening Tests.
• Gene silencing and genome editing include Zinc Finger Nuclease Technology (ZFN), Transcription-Activator-Like Effector Nuclease (TALEN) Technology, and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPRs).
• Genetic testing and gene therapy are correct applications of DNA technology.
• Polymerase Chain Reaction (PCR) is the first and best-known amplification technique that uses DNA polymerase to rapidly replicate specific DNA sequence in a test tube.
• Biotechnology is the use or alteration of cells or biological molecules for specific applications.
• Both biotechnology and genetic testing are patentable.
• Fluorescence In Situ Hybridization (FISH) is capable of highlighting individual genes and is more preferred than conventional chromosome staining because it uses DNA probes.
• A transgenic organism has DNA from different species.
• Synonymous Substitution, also known as Silent Substitution, involves mutations in the nucleotide sequence that do not change the amino acid sequence, particularly in mutations that occur in the third codon position.
• Hypomorphic Mutation, also known as Leaky Mutation, reduces, but does not completely eliminate gene expression or the activity of the gene product.
• Loss-of-function Mutation, also known as Knockout or Null Mutation, results in complete gene inactivation or a completely non-functional gene product.
• Unconditional Mutation is expressed under permissive as well as restrictive conditions.