Quick Revision Sheet: Biology for RRB CBT
⚡ Last-day crammer – skim, don’t read!
1. Cell & Cell Organelles – “PMR-CLGN-MVP”
| Organelle |
Key Job |
Memory Hook |
| Plasma-membrane |
Gatekeeper |
“P” for Police |
| Mitochondria |
ATP (energy) |
“M” for Money |
| Ribosome |
Protein factory |
“R” for Readymade |
| Chloroplast |
Photosynthesis |
Only in plants |
| Lysosome |
Suicide bag |
“L” for Lethal |
| Golgi |
Packing & postage |
“G” for Gift-wrap |
| Nucleus |
Brain (DNA) |
“N” for Netaji |
🔖 Rule: Prokaryotes lack membrane-bound organelles; Eukaryotes have them.
6CO₂ + 6H₂O ―Sunlight+Chlorophyll→ C₆H₁₂O₆ + 6O₂
Shortcut: “6-6-1-6” (CO₂-H₂O-Glucose-O₂)
3. Human Body Systems – “CARES-DREN”
| System |
Chief Point |
Mnemonic |
| Circulatory |
Heart 4-chambers |
“C” for Cycle pump |
| Respiratory |
Alveoli = gas swap |
“R” for Reverse osmosis |
| Excretory |
Nephron unit |
“E” for Exit gate |
| Skeletal |
206 bones |
Adult = 206, New-born = 270 |
| Digestive |
Longest = Small intestine (6 m) |
“D” for Dinner tube |
4. Blood – “BBC-CLP”
| Component |
Normal Count |
Exam Trap |
| RBC |
5 million/µL |
No nucleus |
| WBC |
5 000–11 000/µL |
Fight infection |
| Platelets |
1.5–4 lakh/µL |
Clotting |
| Haemoglobin |
Men 14–16 g/dL, Women 12–14 g/dL |
O₂ carrier |
Universal donor = O⁻ (O-negative)
Universal recipient = AB⁺
5. Disease & Carrier – “2-TB, 2-V, 2-P”
| Disease |
Cause |
Vector / Carrier |
| TB |
Bacteria (Myco.) |
Air droplets |
| Typhoid |
Bacteria (Sal.) |
Contaminated water |
| Malaria |
Protozoa (Plas.) |
Female Anopheles |
| Kala-azar |
Protozoa (Leish.) |
Sand-fly |
| AIDS |
Virus (HIV) |
Blood / Body fluid |
| Hep-B |
Virus |
Blood / Syringe |
6. Genetics – Mendel’s 3:1
- Dominant > Recessive (Tall = Dominant)
- Genotype = Letter code (TT, Tt, tt)
- Phenotype = Look (Tall, Dwarf)
7. Plant Kingdom – “BAG-F”
| Group |
Vascular? |
Seeds? |
Example |
| Bryophyta |
❌ |
❌ |
Moss |
| Angiosperm |
✅ |
✅ Covered |
Mango |
| Gymnosperm |
✅ |
✅ Naked |
Pine |
| Fungi |
❌ (separate) |
❌ |
Mushroom |
8. Vitamins & Night-Deficiency – “ABCDE-K”
| Vitamin |
Deficiency Disease |
Quick Note |
| A |
Night-blindness |
Carrot (β-carotene) |
| B₁ |
Beri-beri |
Rice polish |
| C |
Scurvy |
Citrus |
| D |
Rickets |
Sun-light |
| K |
Clotting failure |
Green leafy |
9. Common Exam Q&A – Micro-Capsules
1. Largest human cell?
Ovum (egg cell)2. Power-house of cell?
Mitochondria3. Normal blood pressure?
120/80 mmHg4. CO₂ transport mainly as?
Bicarbonate ion (HCO₃⁻)5. Father of Genetics?
Gregor Mendel6. Total cranial nerves?
12 pairs7. pH of human blood?
7.4 (slightly alkaline)8. Yellow fever vector?
Aedes aegypti mosquito
10. 60-Second Table – Must-Know Numbers
| Fact |
Number |
| Chromosomes in man |
46 (23 pairs) |
| RBC life span |
120 days |
| Normal heartbeat |
72/min |
| IQ formula |
(Mental age ÷ Real age) × 100 |
| Vaccine for TB |
BCG |
| Vaccine for Polio |
OPV (oral) |
| Vaccine for Tetanus |
TT |
| Insulin source |
Pancreas (β-cells) |
🎯 Last-night chant: “PMR-CLGN-MVP, 6-6-1-6, O⁻ AB⁺, BBC-CLP, BAG-F, A-B-C-D-K”
All the best—attempt, don’t leave!
BETA
