Transcription + Translation, Domestication

Vocabulary cards covering transcription, translation, RNA types, genetic code, domestication, plant breeding, transgenic technology, cloning, and related terms.

Transcription

First step of gene expression, where DNA is converted into mRNA.

1. rRNA goes to the nucleus

2. Uses RNA polymerase to separate the DNA strands

3. Attaches itself onto the DNA strand (Promoter) and uses it as a template to synthesize a complementary RNA strand.

4. When complete, mRNA detaches from the DNA and moves the the cytoplasm.

Translation

Process where ribosomes use mRNA to assemble amino acids into a polypeptide chain in the cytoplasm.

1. mRNA is found by ribosomes or endoplasmic reticulum in the cytoplasm.

2. It enters the ribosome and tRNA carries amino acids to the ribosome according to the codons of the mRNA sequence.

3. When complete a codon stop pauses the translation, releasing the completed polypeptide chain.

RNA Polymerase

Enzyme that binds to a promoter and builds an RNA strand during transcription.

Promoter Region

Specific DNA sequence at the start of a gene where RNA polymerase attaches to begin transcription.

Ribose

Five-carbon sugar found in RNA nucleotides instead of deoxyribose.

Uracil (U)

RNA base that replaces thymine and pairs with adenine during transcription.

Messenger RNA (mRNA)

RNA molecule that carries the genetic ‘blueprint’ from DNA to the ribosome for protein assembly.

Ribosomal RNA (rRNA)

RNA that combines with proteins to form ribosomes, the sites of polypeptide assembly.

Transfer RNA (tRNA)

RNA that delivers specific amino acids to the ribosome and matches them to codons on mRNA.

Codon

Three-base sequence on mRNA that specifies a particular amino acid or stop signal.

Genetic Code

Set of 64 mRNA codons—61 coding for amino acids and 3 serving as stop signals—nearly universal in life.

Start Codon (AUG)

mRNA codon that signals initiation of translation and codes for methionine.

Domestication

Genetic alteration of wild plants (or animals) by humans to meet agricultural or other needs.

Selection Pressure

Human or environmental factors that favor certain heritable traits, guiding crop evolution toward desired features.

Systematic Plant Breeding

Modern, goal-oriented program to improve crop yield, disease resistance, and stress tolerance through controlled crosses.

Transgenic Organism (GMO)

Organism whose genome contains DNA from an unrelated species, giving new traits beyond natural breeding limits.

Gene Splicing

Molecular technique that inserts foreign genes into an organism’s DNA to create transgenic lines.

Protoplast Fusion

Method of combining plant cells without cell walls to merge their genomes and create novel hybrids.

Agrobacterium tumefaciens

Soil bacterium used as a ‘natural genetic engineer’ to transfer desired genes into plant chromosomes.

Bt Toxin Gene

Bacterial gene introduced into crops (e.g., Bt cotton) to produce insecticidal proteins against pests.

Bioreactor Plant

Transgenic plant engineered to manufacture pharmaceuticals such as vaccines within its tissues.

Gene Cloning

Insertion and replication of foreign DNA within bacteria to produce multiple identical gene copies.

Somatic Cell Nuclear Transfer

Cloning technique where a donor nucleus is placed into an enucleated egg to create an embryo.

Dolly the Sheep

First mammal cloned from an adult somatic cell nucleus via somatic cell nuclear transfer.

Therapeutic Human Cloning

Creation of embryos by nuclear transfer to harvest stem cells for treating diseases like Alzheimer’s or diabetes.

Early breeding

practices that involve selecting plants or animals based on desirable traits to enhance generations.

Systematic plant breeding

involves methodical techniques to select and hybridize plants to achieve desired characteristics, improving crop yield and resilience.