Genotype and Phenotype Quiz

Genotype and Phenotype

• Genotype refers to an organism's genetic makeup (specific alleles or genes).
• Phenotype refers to observable traits.

DNA Structure and Function

• DNA is a double helix composed of two strands.
• It carries genetic instructions for all living organisms.
• DNA stores information for growth, development, and function.

RNA Structure and Function

• RNA is a nucleic acid, often single-stranded.
• Crucial in protein synthesis.
• Can have other functions, like catalyzing reactions or regulating genes.

Base Pairing

• DNA: Adenine (A) pairs with Thymine (T), Cytosine (C) pairs with Guanine (G).
• RNA: Adenine (A) pairs with Uracil (U), Cytosine (C) pairs with Guanine (G).
• Hydrogen bonds hold base pairs together.

DNA Polymerase Directionality

• DNA polymerase synthesizes DNA in the 5' to 3' direction.

Transcription, Translation, and Replication

• Transcription: Copying DNA to RNA. (Occurs in the nucleus in eukaryotes)
• Translation: Using RNA to synthesize proteins in the cytoplasm (ribosomes).
• Replication: Copying DNA for cell division.

Transfer RNA (tRNA)

• tRNA is located in the cytoplasm.
• tRNA brings amino acids to ribosomes during protein synthesis.

Components of Transcription

• Sigma factor: Protein that helps RNA polymerase recognize promoters.
• RNA polymerase: Enzyme that synthesizes RNA.
• Promoter: DNA sequence signaling the start of a gene.

Mutations

• Germ cell mutations are inheritable.
• Somatic cell mutations are not passed to offspring.

Plasmids

• Plasmids are small, circular DNA molecules.
• Common in bacteria.
• Can carry genes like antibiotic resistance.
• Can be transferred between cells (horizontal gene transfer).

Prokaryotes

• Prokaryotes are single-celled organisms without a nucleus or membrane-bound organelles.
• Usually have a single circular chromosome.

Plasmid Incorporation

• Antibiotic resistance genes can be incorporated into plasmids.
• Detecting recombinant cells: antibiotic resistance.

PCR (Polymerase Chain Reaction)

• PCR amplifies specific DNA sequences.
• Enables millions of copies of a segment for analysis.

Electrophoresis

• Electrophoresis separates DNA, RNA, or proteins based on size and charge.

Microbial Control

• Sterilization: Kills all microbes, including endospores.
• Disinfection: Kills vegetative pathogens but not necessarily endospores.
• Antiseptic: Disinfectant used on living tissue.
• Sanitization: Reduces microbial load on surfaces.
• Degermation: Reduces the number of microbes, usually through mechanical means.

Heat Control

• Moist heat works by denaturing proteins.
• High temperatures kill cells, low temperatures inhibit growth.

Radiation Control

• Ionizing radiation removes electrons, damaging microbial DNA.

Chemical Control

• Iodine (e.g., Betadine): Used as a disinfectant or antiseptic.
• Silver nitrate: Used for burn treatment.
• Detergents: Low-level germicides.

Hepatitis C

• Highly transmittable through bodily fluids (e.g., blood).
• High risk of chronic liver disease and cirrhosis.

Microbial Resistance

• Mechanisms of resistance include:
  • Conjugation
  • Transformation
  • Transduction

Immune System Reaction to Drugs

• Drug allergy is an immune system reaction to medication.

Superinfection

• Occurs when antibiotics disrupt normal flora, allowing resistant bacteria to overgrow.

Selective Toxicity

• Antibiotics target bacterial structures without harming human cells.

Drug Mechanisms of Action

• Sulfonamides interfere with metabolism.
• Penicillin blocks cell wall synthesis.
• Tetracyclines block tRNA attachment, stopping synthesis.
• DNA gyrase inhibitors prevent DNA coiling.
• Polymyxins disrupt cell membranes.

Antiviral Drugs

• Inhibit viral replication, mutation, or attachment.

Conjugation

• Genetic material transfer between bacteria via direct contact.

COPD

• Chronic Obstructive Pulmonary Disease.

Fungi (Mold and Yeast)

• Both eukaryotes in the kingdom Fungi.
• Molds grow in filamentous structures; yeasts grow as single cells.

Frameshift Mutations

• Result from the insertion or deletion of a nucleotide(s).
• Shift the reading frame of the genetic code.

DNA Fingerprinting

• Used to identify individuals, assess relationships, and more.
• Can be used in forensics and genetic studies.

Laboratory Techniques

• Pasteurization: heating liquids to kill microbes without damaging the product.
• Isoniazid is a medication for tuberculosis (TB).
• Candidiasis: fungal infection causing yeast infections in women.
• Antimicrobials are used to treat fungal, protozoal, and other parasitic infections.