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Regulation of Gene Expression

Process that controls when and how genes are expressed, occurring at various stages, primarily pre-transcription.

Transcription Factors

Proteins that help regulate the transcription of genes by encouraging or inhibiting RNA polymerase binding.

Epigenetic Changes

Modifications in DNA packaging that affect gene accessibility to transcription machinery.

Operons

Clusters of genes in bacteria controlled by a single promoter; they function together.

Structural Genes

Genes that code for enzymes needed in chemical reactions, transcribed simultaneously.

Promoter Gene

The region where RNA polymerase binds to initiate transcription.

Operator

Region that controls transcription; site where the repressor binds.

Regulatory Gene

Codes for a repressor protein that can block transcription by binding to the operator.

Post-transcriptional Regulation

Control that occurs after RNA is created, deciding whether it will be translated into a protein.

RNAi

RNA interference molecules that bind to RNA and prevent translation.

Morphogenesis

The process during embryonic development where cells change shape and organization.

Homeotic Genes

Early genes that determine the fate of cells in the developing embryo.

Hox Genes

A subset of homeotic genes that play a crucial role in the development of body plans.

Mutation

An error in the genetic code, potentially caused by DNA damage.

Base Substitution Mutation

A mutation where one nucleotide base is substituted for another.

Nonsense Mutation

A mutation that turns a codon into a stop codon, leading to early termination of protein synthesis.

Missense Mutation

A mutation that alters a codon resulting in a different amino acid being produced.

Silent Mutation

A mutation that changes a codon but does not alter the amino acid sequence.

Frameshift Mutation

Mutations caused by insertions or deletions that alter the reading frame of codons.

Gene Duplications

Result in extra copies of genes, often due to unequal crossing-over during meiosis.

Inversions

Changements in the orientation of chromosomal regions.

Translocations

Occur when segments from different chromosomes exchange places, potentially disrupting genes.

Transposons

Gene segments that can move within the genome, potentially disrupting gene function.

Fission

The process by which bacteria divide, although it does not enhance genetic diversity.

Conjugation

A process allowing bacteria to exchange DNA and increase genetic variation.

Bacteriophages

Viruses that infect bacteria and can replicate through lytic or lysogenic cycles.

Lytic Cycle

A viral replication cycle where the virus immediately uses the host's machinery to replicate.

Transduction

The transfer of DNA between bacterial cells via a lysogenic virus.

Enveloped Viruses

Viruses that have a lipid envelope surrounding their capsid.

Retroviruses

RNA viruses that reverse transcribe their RNA to DNA via reverse transcriptase.

Recombinant DNA

DNA created by combining DNA from multiple sources to form a new DNA molecule.

Genetic Engineering

The technology that transfers genes between cells to produce new organisms or products.