Science Majorship: Genetics & Biotechnology (Session 5)

Flashcards covering fundamental concepts in Genetics and Biotechnology, including molecular biology tools, genetic engineering techniques, and agricultural/medical applications.

Nucleotide

The monomer building block of nucleic acids composed of a nitrogenous base, a sugar, and a phosphate group (A, T, C, G).

Gene

A specific DNA sequence that serves as the fundamental physical and functional unit of heredity.

Chromosome

A thread-like condensed DNA molecule that acts as a structural package containing hundreds to thousands of genes.

Genome

The complete set of DNA and entire genetic material present in an organism.

Ribosomes

Organelles found in the cytoplasm or Rough ER that synthesize proteins via mRNA translation; often called 'protein factories of the cell.'

Mitochondria

The 'powerhouse of the cell' that converts glucose into ATP via aerobic respiration in the cytoplasm.

Lysosomes

Organelles known as 'suicide bags' or 'garbage collectors' that break down macromolecules and worn-out organelles.

Plasmid

A small, circular, extrachromosomal DNA molecule found in bacteria that is widely used as a gene vector in recombinant DNA technology.

Nucleoid Region

The area in bacteria containing large, circular chromosomal DNA and proteins that store core genomic instructions.

Restriction Enzymes

Also known as 'Molecular Scissors,' these enzymes cut DNA at specific palindromic sequences by cleaving phosphodiester bonds.

DNA Ligase

Known as 'Molecular Glue,' this enzyme joins broken DNA fragments by sealing sugar-phosphate backbones.

DNA Polymerase

The 'Molecular Builder' that synthesizes new complementary DNA strands and is the primary enzyme in DNA replication and PCR.

Helicase

Known as the 'DNA Unzipper,' it unwinds double-stranded DNA by breaking hydrogen bonds to create the replication fork.

Reverse Transcriptase

An enzyme used as an RNA-to-DNA converter that synthesizes complementary DNA ($\text{cDNA}$) using an RNA template.

Recombinant DNA

Hybrid DNA molecules formed by combining genetic material from two or more distinct species or sources.

Polymerase Chain Reaction (PCR)

A technique used for exponential DNA amplification ($2^n$ copies) in vitro through thermal cycling using a heat-stable DNA polymerase.

Gel Electrophoresis

A laboratory method used to separate DNA, RNA, or proteins by size using an electrical field where DNA, being negatively charged, runs toward the positive anode (red pole).

Transformation

The direct uptake of free, naked extracellular DNA from the environment by a competent bacterial cell.

Transduction

A gene transfer mechanism where a viral vector, specifically a bacteriophage, transfers bacterial DNA between hosts.

Conjugation

The transfer of genetic material between bacterial cells through direct physical contact via a sex pilus or conjugation bridge.

Transgenic Organism

An organism that contains foreign genes introduced from a different species, such as Bt Corn or Golden Rice.

DNA Fingerprinting

A technique that analyzes STR (Short Tandem Repeat) or VNTR sequence patterns to identify individuals for forensics or paternity tests.

Human Genome Project

An international scientific research project (1990–2003) with the goal of mapping and sequencing all 3.2 billion base pairs of the human genome.

Locus

The specific physical coordinate or 'address' on a chromosome where a gene or allele is located.

Telomere

Repetitive non-coding DNA sequences at the ends of linear chromosomes that protect them from degradation during cell division.

Kinetochore

A protein complex assembled at the centromere that attaches to spindle fibers during cell division.

Allele

Different versions or molecular sequence variants of the same gene that determine specific trait variations.

Genome

The master and complete set of all genetic instructions in an organism, primarily composed of DNA.

Transcriptome

The complete set of all expressed RNA transcripts (mRNA, rRNA, etc.) in a cell at a specific time.

Proteome

The entire set of expressed proteins and amino acid chains that function as the molecular machinery of a cell.

Metabolome

The complete collection of small-molecule chemical metabolites, such as lipids and sugars, within a biological sample.

Agrobacterium tumefaciens

Considered 'Nature's genetic engineer,' this bacterium uses a Ti Plasmid to naturally transfer genes into plant chromosomes.

Bacillus thuringiensis (Bt)

A bacterium used as a source of insect resistance genes (Cry genes) because it produces insecticidal crystal proteins.

CRISPR-Cas9

A technology for precise, sequence-specific genome editing in living cells using a guide RNA (gRNA) and the Cas9 endonuclease.

Gene Therapy

A therapeutic application that involves inserting functional genes into a patient's cells to replace or correct defective ones.

mRNA Vaccine

A vaccine platform that uses synthetic viral mRNA in a lipid shell to instruct host ribosomes to build viral proteins internally.

Personalized Medicine

A precision medicine model where treatments are tailored to an individual based on their specific biomarker or DNA profile.

Golden Rice

A genetically modified crop engineered with genes from Daffodil and Bacteria to produce beta-carotene (Pro-Vitamin A).

Karyotyping

A diagnostic technique that analyzes the number and visual appearance of an arranged chart of 23 homologous chromosome pairs.

AquaAdvantage Salmon

The first genetically modified animal approved for human consumption, designed with a growth hormone gene to reach market size faster.

Somatic Cell Nuclear Transfer (SCNT)

A common cloning technique involving the transfer of a somatic cell nucleus into an enucleated egg to create a genetically identical organism.

Promoter Sequence

A regulatory DNA sequence located upstream (5' end) that binds RNA polymerase to initiate and control gene transcription.

Southern Blotting

A diagnostic procedure used to detect specific DNA sequences in a sample using labeled complementary DNA or RNA probes.

Bioremediation

The use of microorganisms to break down and clean up environmental pollutants like oil spills and industrial waste.

Point Mutation

A type of mutation involving the replacement or substitution of a single nucleotide base with another.

Genotype

The complete genetic or allelic constitution of an organism, which cannot be observed directly.

Phenotype

The observable physical and biochemical traits of an organism, resulting from the interaction of its genotype and the environment.

Haploid

A cell or organism having one set of unpaired chromosomes ($1n$), such as gametes (sperm and egg cells).

Diploid

A cell or organism having two complete sets of paired chromosomes ($2n$), such as human somatic cells.

Biopharming

The use of genetically modified plants or animals as 'bioreactors' to produce pharmaceutical substances like vaccines and antibodies.

Pluripotent Stem Cell

A stem cell that has the capacity to differentiate into any of the cell types of the adult body (all three germ layers).

Introns

Non-coding segments of a pre-mRNA transcript that are excised and removed before translation occurs in eukaryotes.

Exons

The coding regions of a gene that are retained in mature mRNA and translated into protein.

Transcription

The process of using a DNA template to create a complementary RNA copy of a specific gene.

Translation

The cellular process where ribosomes read mRNA codons to build a corresponding polypeptide chain (protein).

Biotechnology

The use of biological processes, organisms, or systems to manufacture products intended to improve the quality of human life.