# Genetics & DNA — Mendel to CRISPR Canonical URL: https://shipslides.com/d/catalog-science-genetics Raw viewer URL: https://content.shipslides.com/d/catalog-science-genetics/raw Category: Science Slides: 13 Updated: 2026-05-17T20:55:48.594Z Tags: catalog, science, genetics ## Summary DECK / 5'-GENETICS-3' 2026 / SCIENCE // THE MOLECULAR ARCHIVE GENETICS / The Four-Letter Alphabet From a monastery garden to programmable molecules — how four bases (A, T, G, C) became the operating system of life. Key sections include: GENETICS / The Four-Letter Alphabet; Mendel's Peas; The Double Helix; DNA → RNA → Protein; 64 codons → 20 amino acids; The Human Genome Project; "Junk" DNA, reconsidered; Mutations: the source code of variation; PCR: the photocopier of biology; Reading DNA: 100,000× cheaper. ## Slide Outline 1. GENETICS / The Four-Letter Alphabet 2. Mendel's Peas 3. The Double Helix 4. DNA → RNA → Protein 5. 64 codons → 20 amino acids 6. The Human Genome Project 7. "Junk" DNA, reconsidered 8. Mutations: the source code of variation 9. PCR: the photocopier of biology 10. Reading DNA: 100,000× cheaper 11. CRISPR-Cas9 programmable editing 12. The programmable body 13. References & further reading ## Slide Transcript ### Slide 1: GENETICS / The Four-Letter Alphabet - DECK / 5'-GENETICS-3' - 2026 / SCIENCE - // THE MOLECULAR ARCHIVE - From a monastery garden to programmable molecules — how four bases (A, T, G, C) became the operating system of life. - 5'ATGCATGAAGAT...3' ### Slide 2: Mendel's Peas - 02 / FRAME - 1866 — BRNO - Frame 02 / Origin - In an Augustinian monastery in Brno, Gregor Mendel cross-bred 28,000 pea plants and discovered that traits were inherited as discrete particles — not blended liquids. - Dominant & recessive alleles (3:1 ratios) - Independent assortment — separate traits - Particulate inheritance — units, not fluids - Published 1866. Ignored for 34 years, until rediscovered in 1900 - P × P → F1 → F2 - P: YY × yy (yellow × green) - F1: Yy Yy Yy Yy (all yellow) - F2: YY Yy Yy yy → 3 : 1 - A monk's data table that, decades later, would name a science. ### Slide 3: The Double Helix - 03 / FRAME - 1953 — CAMBRIDGE - Frame 03 / Structure - April 1953, Nature: Watson & Crick publish a one-page paper proposing DNA's antiparallel double helix — built on Rosalind Franklin's X-ray crystallography (Photo 51). - Two strands wound around a common axis - Bases pair inside: A↔T, G↔C - Franklin: the experimental backbone of the discovery - "It has not escaped our notice…" — replication mechanism implicit ### Slide 4: DNA → RNA → Protein - 04 / FRAME - CENTRAL DOGMA - Frame 04 / Information Flow - Crick's 1958 "central dogma": genetic information flows in one direction. DNA stores it, RNA transports it, ribosomes translate it into the molecular machines (proteins) that do the work. - Replication - DNA → DNA. Polymerases unzip the helix and copy each strand semi-conservatively before cell division. - ATGC ⇋ TACG - Transcription - DNA → mRNA. RNA polymerase reads a gene; thymine (T) becomes uracil (U). - ATGC → AUGC - Translation - mRNA → protein. Ribosomes read codons (3 bases) and chain amino acids into a folded protein. - AUG = Met · start ### Slide 5: 64 codons → 20 amino acids - 05 / FRAME - THE CODE - Frame 05 / Codon Table - Three-letter words spell every protein in every species. The code is redundant (multiple codons per amino acid) and nearly universal — bacteria, ferns, and humans share it. - AUG = start codon (Met) - UAA / UAG / UGA = stop codons - Cracked 1961–66 by Nirenberg, Khorana, Holley - AUGMet·M - UUUPhe - UUCPhe - UCUSer - UCCSer - UAUTyr - UAASTOP - UAGSTOP - CUULeu - CUCLeu - CUALeu - CCUPro - CAUHis - CAAGln - CGUArg - CGCArg - AUUIle - ACUThr - AAUAsn - AAALys - AGUSer - AGAArg - GUUVal - GCUAla - GCCAla - GAUAsp - GAAGlu - GGUGly - GGCGly - GGAGly - UGGTrp - UGASTOP - Excerpt — 32 of 64 codons shown. ### Slide 6: The Human Genome Project - 06 / FRAME - 1990–2003 - Frame 06 / The Atlas - Thirteen years, 20 institutions, $2.7 billion. Completed in 2003 — a complete reference of human DNA. The biggest surprise wasn't what it contained, but how little. - 3.0B - Base pairs in the human genome - ~20,000 - Protein-coding genes (fewer than expected) - Of DNA actually codes for proteins - For comparison: a rice plant has ~32,000 protein-coding genes. Complexity isn't about gene count — it's about regulation. ### Slide 7: "Junk" DNA, reconsidered - 07 / FRAME - NON-CODING - Frame 07 / Reconsidered - For decades, the 98% of DNA that didn't code for proteins was dismissed as junk. The ENCODE project (2012) and successors have rewritten that story. - Regulatory elements — promoters, enhancers, silencers - Non-coding RNA — microRNA, lncRNA, structural RNA - Transposons — "jumping genes" (~45% of the genome) - Evolutionary playground — raw material for new genes - ■ Protein-coding 2% - ■ Regulatory ~8% - ■ Introns ~25% - ■ Repetitive / transposons ~50% - ■ Other / unknown ~15% ### Slide 8: Mutations: the source code of variation - 08 / FRAME - VARIATION - Frame 08 / Errors as Fuel - Copy-machine errors in DNA replication generate the raw material for evolution — and most disease. Three flavors: - Point mutation - One base swapped for another. Sickle cell: a single A→T changes one amino acid in hemoglobin. - GAG → GTG - Frameshift - Insertion or deletion shifts the reading frame — every codon downstream changes. Often catastrophic. - ATG CAT GAT - ↓ ins A - ATG ACA TGA - Copy-number - Whole sections duplicated or deleted. Down syndrome: a third copy of chromosome 21. - [gene] × 1 - [gene][gene] × 2 - [gene][gene][gene] × 3 ### Slide 9: PCR: the photocopier of biology - 09 / FRAME - 1983 — MULLIS - Frame 09 / Amplification - Driving on Highway 128 in 1983, Kary Mullis sketched a chain reaction that would double DNA every cycle. Thirty cycles → a billion copies of any chosen sequence. - Denature at 95°C — strands separate - Anneal at 55°C — primers bind targets - Extend at 72°C — Taq polymerase copies - From forensics to COVID tests — every modern lab depends on it - Electrophoresis Gel - L1L2L3L4L5L6 ### Slide 10: Reading DNA: 100,000× cheaper - 10 / FRAME - READ-OUT - Frame 10 / Sequencing - Three generations of technology compressed the cost of a human genome from billions to hundreds of dollars in two decades. - 1977 — SANGER - Chain-termination method. Read length ~1 kb. Powered the Human Genome Project. ~$1/base. - 2005 — ILLUMINA / NGS - Massively parallel short-read sequencing. Billions of reads per run. $1000 genome by ~2014. - 2015 — NANOPORE / LONG-READ - Oxford Nanopore: thread DNA through a protein pore, read electrical signals. Pocket-sized. Reads of 100kb+. ~$200 genome today. ### Slide 11: CRISPR-Cas9 programmable editing - 11 / FRAME - 2012 — DOUDNA / CHARPENTIER - Frame 11 / The Edit - Borrowed from a bacterial immune system: a guide RNA escorts the Cas9 enzyme to a precise location in the genome, where it cuts. Cellular repair finishes the edit. - 2012 — Doudna & Charpentier reprogram Cas9 in a test tube - 2020 — Nobel Prize in Chemistry - 2023 — Casgevy: first FDA-approved CRISPR therapy (sickle cell) - From decades of work to days of design ### Slide 12: The programmable body - 12 / FRAME - FRONTIER - Frame 12 / What's Next - Editing went from cutting (CRISPR) to rewriting (base editing) to drafting (prime editing). Genetic medicine is moving from theory to clinic. - Gene therapies - One-time treatments for hemophilia, retinal blindness, spinal muscular atrophy. AAV viral vectors deliver corrected genes directly to target cells. - Base & prime editing - Rewrite single letters without cutting both strands. Prime editing (Liu, 2019) handles ~89% of known disease-causing mutations. - Personalized medicine - Pharmacogenomics tailors drugs to your variants. mRNA vaccines designed in days. Cancer immunotherapies engineered patient by patient. - Ancestry & populations - 23andMe-class consumer kits, ancient DNA from 400,000-year-old bones, the rewriting of human prehistory through genomes. - Synthetic biology - Designing organisms from scratch. Minimal genomes (Mycoplasma JCVI-syn3.0). Engineered yeast that brews insulin, spider silk, vaccine adjuvants. - Open questions - Germline editing ethics. Off-target effects. Equity of access. What does it mean to "fix" a genome? ### Slide 13: References & further reading - 13 / END FRAME - 3'-STOP-5' - // END OF SEQUENCE - YouTube — CRISPR gene editing - YouTube — Double helix · Watson & Crick - Nature Education — Discovery of DNA structure - NIH — Human Genome Project archives - Nobel 2020 — CRISPR (Doudna · Charpentier) - // FIN — A · T · G · C ## Related Decks - [Genetics](https://shipslides.com/d/science-genetics) - [Genetics and Genomics](https://shipslides.com/d/science-genetics-and-genomics) - [CLIMATE / Earth's thermostat in motion](https://shipslides.com/d/catalog-science-climate) - [Cosmology / 13.8 billion years, briefly](https://shipslides.com/d/catalog-science-cosmology)