Introduction
The subtopic Biology & Health occupies a critical position in the RPSC General Science paper. It spans the entire spectrum of life sciences—from molecular genetics to ecosystem ecology, from human nutrition to disease dynamics, and from agricultural biotechnology to cutting-edge nanomedicine. Over the years, this area has generated a substantial number of questions (36 in the available dataset), making it one of the most consistently tested segments. The questions reflect the RPSC’s dual expectation: a solid grounding in classical biology (e.g., chromosomal disorders, blood groups, nutrient deficiencies) and awareness of contemporary scientific developments (e.g., DNA fingerprinting, DRDO polyherbal products, carbon footprint, nanotechnology generations).
The syllabus bullet “General Science and Science & Technology” is deliberately broad. In practice, RPSC uses it to test both fundamental concepts (what is a trisomy, how does Rh incompatibility work) and applied knowledge (which bio-fertilizer is used for cattle, what are millet crops, how is compost made). The difficulty level is moderate—most questions are factual, but some require careful matching or understanding of cause-and-effect (e.g., why calcium carbide ripens fruits, why Rh-negative mothers need prophylaxis). There is also a clear pattern of repetition: Down syndrome appears in three separate years (2018, 2021, 2023), malaria-causing Plasmodium species appears twice, and blood group–related questions recur in different forms.
This chapter is designed to take you from zero to exam-ready. We begin with Core Concepts & Foundations, where every essential term is defined from first principles. We then move into six deep-dive sections that mirror the major thematic clusters visible in the PYQs:
- Genetics, Chromosomal Disorders & DNA Technology
- Human Nutrition & Deficiency Diseases
- Blood Groups, Rh Incompatibility & Immunity
- Diseases, Pathogens & Vectors
- Agricultural Biology & Bio‑technology
- Ecology, Biodiversity & Environmental Health Seven additional interconnected topics—nanotechnology, DRDO innovations, carbon footprint, millet crops, and more—are woven into these sections where they logically belong.
Each section is built around the actual tested content. Where a PYQ has been factually incorrect (which happens occasionally in public answer keys), we teach the historically correct fact without apology. Every concept is anchored in the phenomenon, not in rote memorisation. You will find comparison tables for rapid revision, blockquote callouts for critical definitions, and memory aids that turn complex sequences into unforgettable chains. The Worked Examples section walks you through five representative PYQs, showing exactly how to dissect a question and eliminate distractors. PYQ Trends & Patterns gives you a bird’s-eye view of what the examiner loves to repeat. What Else Could Be Asked forecasts the most plausible future questions, so you never get surprised. Common Mistakes & Traps warns you about the subtle pitfalls that cost marks. Finally, the Memory Aids & Mnemonics and Quick Revision sections are your last‑mile tools for the exam hall.
By the end of this chapter, you will not only have memorised the facts but understood the why behind them—and that is what RPSC rewards.
Core Concepts & Foundations
Before we dive into specific topics, let us build a robust conceptual framework. Every key term that appears repeatedly in the PYQs is defined below. Read each definition carefully, and then refer back to it as you encounter the term in later sections.
Trisomy: a condition in which an organism has three copies of a particular chromosome instead of the normal two copies. In humans, trisomy 21 (chromosome 21) causes Down syndrome, the most common chromosomal disorder. Trisomy can occur in other chromosomes, leading to Edwards syndrome (trisomy 18) or Patau syndrome (trisomy 13).
DNA Polymorphism: the existence of two or more forms (alleles) of a DNA sequence in a population, arising from mutations. This variation is the basis of DNA fingerprinting because individuals (except identical twins) have unique patterns of polymorphic regions. Restriction Fragment Length Polymorphism (RFLP) and Short Tandem Repeats (STRs) are common types.
Rh incompatibility: a condition that occurs when an Rh‑negative mother carries an Rh‑positive foetus. During pregnancy or childbirth, the mother’s immune system may be exposed to the foetus’s Rh antigen and produce anti‑Rh antibodies. In subsequent pregnancies with an Rh‑positive foetus, these antibodies can cross the placenta and destroy the foetus’s red blood cells, causing haemolytic disease of the newborn.
Agglutinogen: any antigen that triggers the production of agglutinins (antibodies) and causes clumping (agglutination) of red blood cells. In the ABO blood group system, agglutinogens A and B are present on the surface of red blood cells. Blood group O has neither A nor B agglutinogens, while group AB has both.
Kwashiorkor: a severe form of protein‑energy malnutrition caused primarily by a deficiency of proteins in the diet. It typically occurs in children after weaning, when a high‑carbohydrate, low‑protein diet replaces breast milk. Symptoms include oedema (swollen belly), fatty liver, growth failure, and skin lesions.
Malignant malaria: the most severe form of malaria, caused by Plasmodium falciparum. It can lead to cerebral malaria, organ failure, and death if untreated. The other Plasmodium species (P. vivax, P. ovale, P. malariae) cause benign tertian or quartan malaria with milder symptoms.
Zoonotic disease: an infectious disease that can be transmitted from animals to humans (or vice versa). Examples include plague (from rodents), rabies (from dogs/bats), SARS (from bats/civets), and COVID‑19. Mucormycosis is a fungal infection that is not zoonotic—it is acquired from the environment or from immunocompromised states.
Biomass pyramid: a graphical representation of the total mass of living organisms at each trophic level in an ecosystem. In most terrestrial ecosystems, the pyramid is upright (producer biomass > primary consumer biomass). In marine ecosystems, it can be inverted because phytoplankton (producers) have a very high turnover rate but low standing biomass compared to zooplankton.
Alpha, Beta, Gamma diversity: three indices used to measure biodiversity. Alpha diversity is the mean species diversity within a single habitat at a local scale. Beta diversity measures the change in species composition between habitats. Gamma diversity is the total species diversity over a large geographic area encompassing multiple habitats.
Bio‑fertilizer: a living microbial preparation that helps plants obtain nutrients through natural processes. For example, Rhizobium fixes atmospheric nitrogen in legume roots, Azospirillum fixes nitrogen in non‑legumes, and Azolla (a floating aquatic fern) fixes nitrogen symbiotically with the cyanobacterium Anabaena and can also be used as cattle feed.
Carbon footprint: the total amount of greenhouse gases (primarily CO₂, CH₄, N₂O) emitted directly and indirectly by human activities, usually expressed in equivalent tonnes of CO₂. It includes emissions from transportation, energy use, food production, and all goods and services consumed.
Non‑cellulosic fibre: a fibre that does not contain cellulose as its main structural component. Natural fibres like jute, linen, and rayon (though semi‑synthetic) are derived from cellulose. Nylon, a synthetic polymer, is a non‑cellulosic fibre.
Compost: a rich, organic matter formed by the aerobic decomposition of biodegradable waste (e.g., vegetable peels, livestock excreta, farm waste) in pits or bins. Earthworms accelerate the process (vermicomposting), not slow it down. The incorrect statement in RPSC 2018 was that earthworms slow down decomposition—in reality, they speed it up.
Myopia and Hypermetropia: two common refractive errors of the eye. Myopia (nearsightedness) occurs when the eyeball is too long or the lens too strong, causing distant objects to appear blurry. It is corrected with a concave (diverging) lens. Hypermetropia (farsightedness) occurs when the eyeball is too short or the lens too weak, causing near objects to appear blurry. It is corrected with a convex (converging) lens.
Lichens: symbiotic associations between a fungus and an alga or cyanobacterium. Because they absorb water and nutrients directly from the atmosphere, they are highly sensitive to air pollution, especially sulphur dioxide. Their presence indicates clean air; their absence often signals polluted areas.
Astra missile: India’s first Beyond‑Visual‑Range (BVR) air‑to‑air missile, indigenously developed by the Defence Research & Development Organisation (DRDO). It has a range of over 100 km and is designed to engage targets beyond the pilot’s visual line of sight.
Dolly the sheep: the first mammal cloned from an adult somatic cell (a mammary gland cell). She was born in 1996 (not 1998) at the Roslin Institute in Scotland, died in 2003 due to lung disease, and her birth proved that differentiated cells could be reprogrammed to generate a whole organism.
These core definitions form the bedrock of the entire subtopic. Every subsequent section will elaborate on them, connect them to other concepts, and show how they have been tested. Keep this glossary open as you read.