- Why did Johannsen choose 'gene' as a neutral term with no assumptions about physical structure?
Gene Regulation and Expression
How genes are turned on and off and expressed.
- What did Morgan's discovery prove about the physical nature of genes?
- What is chromosomal crossing over and how did it let Morgan map genes to relative positions?
- How did Morgan's fly-room results overturn the idea that genes were abstract 'elements' rather than physical objects?
- What modern techniques trace their conceptual origin to Morgan's chromosome maps?
- What does the one gene, one enzyme hypothesis actually claim about how cells work?
- Why did most biochemists in the 1940s assume protein, not DNA, carried genetic information?
- Why did some biologists in 1952 still believe proteins were the more likely genetic material?
- What is the operon, and how does it let bacteria turn genes on and off depending on their environment?
- How did studying lactose digestion in bacteria lead Jacob, Lwoff, and Monod to discover gene regulation?
- How does a repressor protein control whether a gene near it gets read or stays silent?
- How did the operon model change the way biologists thought about the genome as a whole?
- How can the immune system generate roughly a billion distinct antibodies from only about 20,000 genes?
- Why is the antibody-generation mechanism described as a combinatorial trick rather than a stored blueprint?
- What criticism did the Human Genome Project face about whether the genome alone would explain human biology?
- What cellular processes besides glycogen breakdown are governed by reversible phosphorylation?
- Why did the discovery of split genes overturn the earlier picture drawn from bacterial genetics?
- How did Mark Ptashne show that repressor proteins control bacteriophage lambda's choice to kill or lie dormant?
- What did the lac operon research by Jacob and Monod establish before Ptashne's work?
- How does a transcription factor recognise and bind a specific DNA sequence?
- Why is Ptashne's work considered foundational to modern cancer drug design?
- How many protein-coding genes did the C. elegans genome turn out to contain, and why did that number surprise researchers?
- What did Robert Roeder discover in 1969 about how higher organisms transcribe genes?
- What additional protein factors did Roeder spend decades identifying, and what do they control?
- How do nuclear receptors bind DNA to switch genes on or off once activated?
- How many genes encode olfactory receptor proteins, and why did this make it the largest known gene family?
- What does RNA polymerase actually do when it transcribes a gene?
- How did Kornberg's crystallography reveal the structure of the transcription machinery?
- How did double-stranded RNA silence genes in Fire and Mello's C. elegans experiments?
- What natural biological role does RNA interference play in cells beyond the laboratory?
- What was Martin Chalfie's key insight for turning GFP into a genetic tag usable in any organism?
- Roughly how much of the human genome do microRNAs regulate, based on research following this discovery?
- How did Yamanaka reset adult mouse cells to a pluripotent state using only four transcription factors?
- What additional 'gears' did Michael Young discover that stabilise and reset the circadian clock?
- How does a microRNA silence a messenger RNA without encoding a protein of its own?
- How did studying a mouse strain that attacked its own organs lead Brunkow and Ramsdell to the FOXP3 gene?
- What regulatory circuits did Shapiro identify that determine whether a Caulobacter daughter cell swims or attaches to a surface?
- What causes isolated cells to exhibit oscillatory dynamics in auxin signalling pathway components, and how does this relate to observed oscillations in ARF target gene expression?
- How can synthetic transcriptional regulators be compiled into genetic circuits that perform Boolean logic operations inside plant cells?
- How does spatial and temporal control of synthetic circuits allow targeted manipulation of the developmental gradients that govern plant growth?