CGPSC MAINS 2019 Paper-4

Points to Remember: Main parts of a flower: sepals, petals, stamens, carpels. Function of each part in reproduction. Variations in flower structure across different species. Introduction: Flowers are the reproductive organs of flowering plants (angiosperms). Their structure is remarkably diverse, reflecting the vast array of plant species and their adaptation to different pollination strategies. Understanding … Read more

Points to Remember: Chromosomes are thread-like structures found in the nucleus of cells. They are composed of DNA and proteins. They carry genetic information in the form of genes. Chromosomes have specific structures that are crucial for their function. Introduction: Chromosomes are fundamental structures within cells that carry the genetic blueprint of an organism. These … Read more

Points to Remember: Chloroplast structure includes outer and inner membranes, stroma, thylakoids, grana, and lamellae. Each component plays a specific role in photosynthesis. The structure facilitates efficient light absorption and energy conversion. Introduction: Chloroplasts are organelles found in plant cells and some protists. They are the sites of photosynthesis, the process by which light energy … Read more

Points to Remember: The question requires a mathematical solution. The approach is purely factual and analytical, focusing on applying algebraic identities to simplify the expression. The final answer will be a numerical value. Introduction: This question asks us to evaluate the expression [(101)⁴ – (99)⁴] / [(101)² + (99)²]. This can be solved using the … Read more

Points to Remember: This is a mathematical word problem requiring an analytical approach. We need to translate the word problem into algebraic equations. The solution will involve solving a system of simultaneous equations. Introduction: This question involves finding two rational numbers (numbers that can be expressed as a fraction) based on the relationship between their … Read more

Points to Remember: Definition of chemical equilibrium. Characteristics of chemical equilibrium. Factors affecting chemical equilibrium. Importance of chemical equilibrium. Introduction: Chemical equilibrium is a dynamic state in a reversible chemical reaction where the rate of the forward reaction equals the rate of the reverse reaction. This doesn’t mean the concentrations of reactants and products are … Read more

Points to Remember: Minerals are naturally occurring inorganic solids with a definite chemical composition and crystalline structure. Ores are minerals or rocks containing economically valuable amounts of metals or other valuable substances. The distinction lies in economic viability: a mineral can be an ore only if it’s profitable to extract the valuable component. Introduction: The … Read more

Points to Remember: Ohm’s Law describes the relationship between voltage, current, and resistance in an electrical circuit. It’s a fundamental law in electronics and electrical engineering. Understanding Ohm’s Law is crucial for analyzing and designing circuits. The law has limitations and doesn’t apply to all materials or situations. Introduction: Ohm’s Law, a cornerstone of electrical … Read more

Points to Remember: Four diverse applications of solar cells showcasing their versatility. Introduction: Solar cells, also known as photovoltaic (PV) cells, are devices that convert sunlight directly into electricity. This conversion is achieved through the photovoltaic effect, where photons (light particles) strike a semiconductor material, causing electrons to be released and generating an electric current. … Read more

Points to Remember: Resistance is the opposition to the flow of current in a conductor. Specific resistance (or resistivity) is the intrinsic property of a material to resist the flow of current. Resistance depends on the material, length, and cross-sectional area of the conductor. Specific resistance depends only on the material and temperature. Introduction: Electrical … Read more