Biology for RRB Group D: What Is Asked
Biology in RRB Group D General Science comes from Class 9 and 10 NCERT Science. The same chapters repeat every year: the cell, tissues, life processes (nutrition, respiration, transport, excretion), control and coordination, reproduction, heredity and evolution, diseases and vitamins, and classification of living things. Questions are one-line facts, so a good table-based revision is the fastest way to score.
Key takeaway: Learn the cell organelles, the vitamin–deficiency table, the human body systems and the main hormones. These four tables answer most biology MCQs in Group D and NTPC.
RRB Group D Biology Syllabus and Important Topics
| NCERT chapter | Most asked points |
|---|---|
| The fundamental unit of life (Class 9) | Organelles and their functions, plant vs animal cell |
| Tissues (Class 9) | Meristematic tissue, xylem and phloem, types of muscle |
| Diversity in living organisms (Class 9) | Five-kingdom classification, scientists |
| Why do we fall ill (Class 9) | Infectious diseases, pathogens, vaccines |
| Life processes (Class 10) | Photosynthesis, digestion enzymes, heart, kidney (nephron) |
| Control and coordination (Class 10) | Brain parts, reflex arc, plant and human hormones |
| How do organisms reproduce (Class 10) | Fission, budding, pollination, fertilisation |
| Heredity (Class 10) | Mendel, dominant and recessive traits, sex determination |
General Science carries 25 of the 100 CBT questions in RRB Group D, shared with physics and chemistry; biology is usually 7–9 of them.
Cell and Cell Organelles: Biology Notes for RRB Group D
| Organelle | Function | Remember |
|---|---|---|
| Nucleus | Controls cell activity; holds DNA | Discovered by Robert Brown (1831) |
| Mitochondria | Aerobic respiration, makes ATP | "Powerhouse of the cell" |
| Ribosome | Protein synthesis | Has no membrane |
| Endoplasmic reticulum | Transport; rough ER makes proteins, smooth ER makes lipids | |
| Golgi apparatus | Packaging and secretion | Named after Camillo Golgi |
| Lysosome | Digestion of waste | "Suicide bags" |
| Plastids (chloroplast) | Photosynthesis | Only in plant cells |
| Vacuole | Storage; large in plant cells | |
| Cell wall | Rigidity; made of cellulose in plants | Absent in animal cells |
Robert Hooke first saw cells in cork in 1665. Mitochondria and plastids have their own DNA and ribosomes.
Human Body Systems for RRB Group D
| System | Key facts |
|---|---|
| Digestive | Saliva has salivary amylase (starch → sugar); pepsin acts in the stomach; bile from the liver emulsifies fats; most absorption in the small intestine (villi) |
| Respiratory | Gas exchange in alveoli; haemoglobin carries oxygen |
| Circulatory | Human heart has 4 chambers; arteries carry blood away from the heart; pulmonary artery carries deoxygenated blood |
| Excretory | Nephron is the filtering unit of the kidney; urea is the main waste |
| Nervous | Neuron is the unit; cerebrum controls thinking, cerebellum balance, medulla involuntary actions |
| Skeletal | Adult human has 206 bones; femur is the longest, stapes (ear) the smallest |
Normal body temperature is about 37 °C. Normal blood pressure is about 120/80 mm Hg. RBC lifespan is about 120 days.
Vitamins and Deficiency Diseases List
| Vitamin | Chemical name | Deficiency disease |
|---|---|---|
| A | Retinol | Night blindness |
| B1 | Thiamine | Beriberi |
| B3 | Niacin | Pellagra |
| B12 | Cobalamin | Pernicious anaemia |
| C | Ascorbic acid | Scurvy |
| D | Calciferol | Rickets (children) |
| E | Tocopherol | Reproductive problems |
| K | Phylloquinone | Delayed blood clotting |
Fat-soluble vitamins: A, D, E, K. Water-soluble: B group and C. Iodine deficiency causes goitre; iron deficiency causes anaemia; protein deficiency causes kwashiorkor.
Human Diseases and Their Causes for Railway Exams
| Caused by | Diseases |
|---|---|
| Virus | Common cold, influenza, measles, polio, dengue, AIDS (HIV), COVID-19 |
| Bacteria | Tuberculosis, typhoid, cholera, tetanus, diphtheria |
| Protozoa | Malaria (Plasmodium, spread by female Anopheles mosquito), kala-azar |
| Fungus | Ringworm, athlete's foot |
BCG vaccine protects against tuberculosis. Dengue and chikungunya are spread by the Aedes mosquito.
Hormones and Glands in Biology for RRB Group D
| Gland | Hormone | Role |
|---|---|---|
| Pituitary ("master gland") | Growth hormone | Growth; excess causes gigantism |
| Thyroid | Thyroxine | Metabolism; needs iodine |
| Pancreas | Insulin | Lowers blood sugar; shortage causes diabetes |
| Adrenal | Adrenaline | "Fight or flight" |
| Testes / ovaries | Testosterone / oestrogen | Puberty changes |
Plant hormones: auxin (growth towards light), gibberellin (stem growth), cytokinin (cell division), abscisic acid (inhibits growth, wilting), ethylene (fruit ripening).
Plant Biology and Heredity Facts
- Photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ in the presence of sunlight and chlorophyll.
- Xylem carries water and minerals upward; phloem carries food (translocation).
- Stomata allow gas exchange and transpiration.
- Gregor Mendel worked on garden pea and is called the father of genetics.
- Human cells have 23 pairs of chromosomes. Females are XX, males XY; the child's sex depends on the chromosome from the father.
- Five-kingdom classification was proposed by R. H. Whittaker (1969).
Biology MCQs for RRB Group D (Practice Set)
- Which organelle is known as the powerhouse of the cell? Answer: Mitochondria. It makes ATP.
- Deficiency of vitamin C causes? Answer: Scurvy.
- The filtering unit of the human kidney is? Answer: Nephron.
- Which blood vessel carries deoxygenated blood from heart to lungs? Answer: Pulmonary artery.
- Malaria is caused by? Answer: Plasmodium (a protozoan). It is spread by the female Anopheles mosquito.
- Which hormone lowers blood sugar? Answer: Insulin, from the pancreas.
- Which plant tissue carries food? Answer: Phloem.
- How many bones does an adult human have? Answer: 206.
- Which plant hormone helps fruit ripening? Answer: Ethylene.
- Who proposed the five-kingdom classification? Answer: R. H. Whittaker.
Biology Mistakes to Avoid in RRB Group D
- Ribosomes are found in both plant and animal cells; only plastids and the cell wall are plant-only.
- Pulmonary artery carries deoxygenated blood and pulmonary vein carries oxygenated blood, the reverse of other vessels.
- Tuberculosis and typhoid are bacterial, not viral.
- Rickets is vitamin D deficiency; night blindness is vitamin A.
Biology for RRB Group D FAQs
How many biology questions come in RRB Group D?
General Science has 25 questions out of 100; biology is usually 7–9 of them, with the rest from physics and chemistry.
Which biology chapters are most important for RRB Group D?
Cell, life processes, control and coordination, heredity, and diseases and vitamins from Class 9–10 NCERT.
Is NCERT enough for RRB Group D biology?
Yes, for most questions. Class 9 and 10 NCERT Science plus a vitamins and diseases list covers the syllabus.
Which vitamin is made in the skin by sunlight?
Vitamin D.
Which is the largest gland in the human body?
The liver.
Practice Next
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