Z_1_07 — Genetic Recombination and Crossing Over

Genetic recombination — the physical exchange of DNA segments between homologous chromosomes during meiosis — is a fundamental biological process that generates genetic diversity, ensures proper chromosome segregation, a

Z_1_04 — Gene Expression and Regulation

Gene expression regulation — the molecular mechanisms controlling when, where, and how much each gene is active — is the central process that enables a single genome to produce ~200 distinct cell types, orchestrate embry

Z_1_01 — ENCODE Project, Non-Coding DNA & Epigenetics

The human genome is ~3.2 billion base pairs long, but only ~1.5% encodes proteins. The remaining ~98.5% was once dismissed as "junk DNA." The ENCODE Project (2003–present) revealed that at least 80% of the genome has bio

Z_1_05 — Genomic Imprinting and Parent-of-Origin Effects

Genomic imprinting is an epigenetic phenomenon in which a gene's expression depends on whether it was inherited from the mother or the father — violating the standard Mendelian assumption that both parental copies functi

Z_1_03 — Human Genome Project and Its Legacy

The Human Genome Project (HGP), launched in 1990 and completed in 2003, was the largest coordinated biological research effort in history — a $3 billion, 13-year international collaboration to sequence all ~3.2 billion b

Z_1_19 — Non-Coding RNA and Gene Regulation

Non-coding RNAs (ncRNAs) — RNA molecules that are transcribed from the genome but do not encode proteins — have emerged as central regulators of gene expression, challenging the classical "one gene–one protein" paradigm

Z_1_10 — Chromosome Evolution and Karyotype

Karyotype — the number, size, and morphology of chromosomes in a cell — varies enormously across species, from n=1 in the ant Myrmecia pilosula to n=630 in the fern Ophioglossum reticulatum. Humans have 2n=46 (23 pairs),

Z_1_12 — Genome Architecture and 3D Organization

The human genome — approximately 6.4 billion base pairs of DNA — is packed into a nucleus only ~6 μm in diameter. If stretched end-to-end, the DNA of a single human cell would extend about 2 meters, yet it is packaged an

Z_1_20 — RNA World Hypothesis

The RNA World hypothesis proposes that life on Earth passed through an early stage in which RNA molecules served as both the carriers of genetic information AND the catalysts of chemical reactions — performing the dual r

Z_1_11 — Polyploidy and Genome Duplication

Polyploidy — the possession of more than two complete sets of chromosomes — is a major force in genome evolution, particularly in plants and some animal lineages. Susumu Ohno (1970) proposed that whole genome duplication

Z_1_14 — Chromatin Remodeling: Epigenetic Architecture of the Genome

Chromatin remodeling — the dynamic restructuring of the protein-DNA complex (chromatin) that packages eukaryotic genomes — is a central mechanism of gene regulation and a cornerstone of epigenetics. In eukaryotic cells,

Z_4_13 — Membrane Biology: Lipid Bilayers, Rafts, and Cellular Boundaries

Biological membranes — the lipid bilayer structures that define cells and compartmentalize their interiors — are fundamental to all life on Earth. Every cell is bounded by a plasma membrane that separates the interior (c

Z_4_05 — Synthetic Biology and Minimal Genomes

Synthetic biology aims to design, construct, and engineer biological systems and organisms with novel functions not found in nature — or to redesign existing biological systems for useful purposes. The field's landmark a

Z_4_00 — RNA Protein Cell Biology: Subfolder Summary

Z_4_06 — Psychedelic Neurochemistry: 5-HT2A, Tryptamines, and Molecular Mechanisms

Psychedelic neurochemistry — the molecular-level study of how psychedelic compounds alter brain function to produce their characteristic effects (visual hallucinations, synesthesia, ego dissolution, mystical-type experie

Z_4_04 — RNA Biology: Types and Functions

RNA (ribonucleic acid) — once considered merely a passive intermediary between DNA and protein — is now recognized as the most functionally diverse class of biological macromolecules, performing roles in catalysis, gene

Z_4_01 — Human Microbiome, Gut-Brain Axis, and the Holobiont Concept

The human microbiome — the ~38 trillion microbial cells (bacteria, archaea, fungi, viruses) inhabiting the human body — constitutes a co-evolved ecosystem that profoundly influences health, immunity, metabolism, developm

K_3_02 — Embodied Cognition

Embodied cognition is a broad research program challenging the classical cognitive science view that the mind is essentially a computer processing abstract symbols in the brain. Instead, embodied cognition holds that thi

K_3_19 — Electrical Synapses and Gap Junctions in Consciousness

Most neuroscience focuses on chemical synapses, but the brain also uses electrical synapses formed by connexin-36 gap junctions — direct cytoplasmic channels that pass ions and small molecules between neurons. These prov

K_3_01 — Machine Consciousness — Can AI Be Aware?

The question of machine consciousness — whether artificial systems can be genuinely aware rather than merely simulating awareness — stands at the intersection of philosophy of mind, neuroscience, and computer science. Jo