Biotechnology
rDNA Technology Steps (RICE) — Remember Restriction enzyme cutting → Insertion of gene → Cloning in vector → Expression in host. This sequence covers the four core steps of recombinant DNA technology for NSEB questions.
Competent Cells (CaCl₂ = Calcium) — Bacterial cells treated with Calcium chloride become capable of taking up DNA. The "Ca-Ca" link helps recall that CaCl₂ makes cells competent for transformation.
PCR Three Temps (9-5-7) — Denaturation at ~95°C, Annealing at ~55°C, Extension at ~72°C. The "9-5-7" descending pattern matches the three temperature steps in each PCR cycle.
Plasmid Features (ORIS) — Ori (origin of replication), Resistance gene (selectable marker), Insertion site (restriction site), Small size. Essential plasmid vector characteristics tested frequently.
Cell Structure and Function
Mitochondrial Membranes (COPS) — Cristae (inner folds), Oxysomes/ATP synthase, Porins (outer membrane), Space between = intermembrane space. Captures key mitochondrial membrane features.
Lysosome = Suicide Bag (Acid pH) — Lysosomes maintain pH ~4.5-5.0 using proton pumps; if membrane ruptures, acidic hydrolases digest the cell itself, hence "suicide bag" coined by de Duve.
Plastid Types (CLC) — Chloroplasts (green/photosynthesis), Leucoplasts (colorless/storage), Chromoplasts (colored/pigments). Covers the three main plastid categories with color cues.
Biomolecules
Essential Amino Acids (PVT TIM HALL) — Phenylalanine, Valine, Threonine, Tryptophan, Isoleucine, Methionine, Histidine, Arginine, Leucine, Lysine. Ten essential amino acids humans cannot synthesize.
Reducing Sugars (All Mono +MAL) — All monosaccharides + Maltose, lActose, but NOT sucrose. Sucrose is non-reducing because both anomeric carbons are locked in glycosidic bond.
Pyrimidines = CUT — Cytosine, Uracil, Thymine are single-ring pyrimidines. Purines (AG) are double-ring; "CUT the PY(rimidine)" helps separate them.
Cell Cycle and Division
Interphase Duration (G₁ > S > G₂) — G₁ is longest, S (synthesis) intermediate, G₂ shortest in most cells. Typical ratios help estimate phase duration from total cycle time questions.
Meiosis I = Reduction Division — Chromosome number halves from 2n→n in Meiosis I (not II). Remember: "I = hIalved" while Meiosis II resembles mitosis maintaining n.
Prophase I Stages (LZPDD) — Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis. The longest meiotic stage sequence frequently tested in NSEB questions.
Animal Kingdom
Phylum Symmetry (RAB) — Radial = Cnidaria/Echinodermata (larvae), Asymmetrical = Porifera, Bilateral = most others (Platyhelminthes onward). Fundamental symmetry classification.
Chordates Features (NOTCH) — Notochord, dorsal hOllow nerve cord, Tail post-anal, pharyngeal gill slits (CH). All four must be present at some life stage.
Coelom Types (ACoPe) — Acoelomate (Platyhelminthes), Coelomate (Annelida onward), Pseudocoelomate (Nematoda/Aschelminthes). Categorizes phyla by body cavity type.
Plant Kingdom
Bryophyte = Amphibians of Plant Kingdom — Require water for fertilization (swimming antherozoids), lack vascular tissue, dominant gametophyte. "Amphibian" analogy captures their transitional water-dependent nature.
Gymnosperm Seeds (NAKED) — Gymnosperm = "naked seed" (no fruit covering); ovules/seeds exposed on megasporophylls. Direct etymological trick from Greek gymnos = naked.
Alternation of Generations (GSD-SHD) — Gametophyte = haploid, Sporophyte = Diploid. Gametophyte produces gametes by mitosis; Sporophyte produces spores by meiosis. Tracks ploidy levels accurately.