Cloning and Cell Potency Quiz

DNA Repair Mechanisms

• Base excision repair fixes damaged bases, while mismatch repair corrects incorrectly paired nucleotides.
• Nucleotide excision repair addresses bulky DNA lesions.
• Direct DNA repair reverses altered nucleotides to their original forms.
• Double-strand breaks are repaired through homologous recombination or nonhomologous end joining.

Types of Mutations

• Transition mutations: Substitution of a purine for another purine (A↔G) or a pyrimidine for another pyrimidine (C↔T).
• Transversion mutations: Substitution of a purine for a pyrimidine or vice versa, leading to eight possible combinations.
• Missense mutations: Change a codon resulting in a different amino acid or change a stop codon to an amino acid codon.
• Nonsense mutations: Convert a codon into a stop codon, terminating protein synthesis prematurely.
• Silent mutations: Codon changes that do not affect the protein sequence due to redundancy in the genetic code.
• Neutral mutations: Alterations that do not affect fitness or phenotype.

Histone Acetylation

• Histone sequences rich in arginine (R) and lysine (K) are more likely to be acetylated, loosening DNA and promoting transcription.

Transcriptome

• The complete set of all RNAs encoded by the genome, crucial in functional genomics.

PAGE

• Polyacrylamide gel electrophoresis (PAGE) separates proteins by size, primarily utilized in proteomics and western blotting.

SNP and CNV

• SNP (Single Nucleotide Polymorphism): Variation at a single base pair in DNA, essential for genome-wide association studies (GWAS).
• CNV (Copy-Number Variation): Changes in the number of copies of particular DNA sequences, often linked to diseases like autism.

RFLP

• Restriction Fragment Length Polymorphism (RFLP): Used to create genetic markers for analysis and disease mapping based on variations in DNA fragment lengths.

GWAS

• Genome-Wide Association Studies (GWAS): Identify genetic variants linked to diseases by comparing genomes of healthy vs. afflicted individuals.

FISH

• Fluorescent in Situ Hybridization (FISH): Technique used to visualize the location of specific genes or mRNA in cells/tissues using fluorescent probes.

CRISPR

• Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR): A gene-editing technology that alters DNA through Cas proteins and CRISPR RNAs.

ChIP

• Chromatin Immunoprecipitation (ChIP): Method used to identify DNA-binding sites of proteins, important for epigenetic studies.

Haplotype

• Variation of DNA on a single chromosome used to study SNPs within specific genetic regions (HapMap project).

RNA-seq

• Technique used to sequence entire RNA populations, determining gene expression levels and analyzing the transcriptome.

Epigenetics

• Acetylation: Addition of acetyl groups to histone tails, promoting gene expression by loosening DNA structure.
• Methylation: Addition of methyl groups to cytosine bases in DNA, typically silencing gene expression.

Totipotency and Cell Potency

• Totipotency: Ability of a single cell to develop into an entire organism.
• Pluripotency: Cells can develop into most body cells, except for placental cells.
• Multipotency: Cells can differentiate into a limited range of cell types.
• Monopotency: Cells that can only develop into one specific cell type, such as red blood cells.

Monozygotic Twins

• Share identical DNA but may differ in epigenetics and phenotype due to environmental effects and gene expression changes over time.

Genomic Imprinting

• An epigenetic mechanism that determines gene expression based on parental origin, often associated with methylation that silences gene activity.

Somatic vs. Germ-line Mutations

• Somatic Mutations: Occur in somatic cells, not passed to offspring, often associated with cancer development.
• Germ-line Mutations: Occur in gametes, inherited across generations, can impact future offspring's phenotype.

Apoptosis vs. Necrosis

• Apoptosis: Programmed cell death, an energy-dependent process that eliminates damaged cells.
• Necrosis: Unprogrammed cell death resulting from injury or disease, often causing inflammation and damage to surrounding tissues.