Living Organisms and Life Processes

Overview

Living Organisms and Life Processes forms a core component of Environmental Studies for KAR TET Paper I, designed for teachers of Classes I–V. This topic helps future primary teachers understand and explain the fundamental difference between living and non-living things—a concept that young children often find confusing.

For the exam, you must know the defining characteristics of living organisms (often called MRS GREN or similar mnemonics), the basic life processes in plants and animals, and how these concepts can be taught to young learners through observation and activity. Questions typically test factual recall of life processes, differences between plant and animal functions, and age-appropriate examples that teachers can use in classrooms.

Mastery of this topic also connects to other EVS areas like biodiversity, food chains, and health—making it a foundational building block for the entire subject.

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Key Concepts

• **Living vs Non-living**: Living things show movement, growth, reproduction, response to stimuli, respiration, excretion, and nutrition. Non-living things lack these characteristics or show only some passively (e.g., a car moves but does not grow or reproduce).

• **Seven Life Processes (MRS GREN)**: Movement, Respiration, Sensitivity (response to stimuli), Growth, Reproduction, Excretion, Nutrition—these are universal to all living organisms.

• **Nutrition in Plants**: Plants are autotrophs; they make their own food through photosynthesis using sunlight, water, carbon dioxide, and chlorophyll.

• **Nutrition in Animals**: Animals are heterotrophs; they depend on plants or other animals for food. Modes include herbivore, carnivore, and omnivore.

• **Respiration**: The process of breaking down food to release energy. Plants and animals both respire—plants take in oxygen through stomata; animals through lungs, gills, or skin.

• **Reproduction**: The process by which organisms produce offspring. Plants reproduce through seeds, spores, or vegetative parts; animals reproduce by laying eggs or giving birth to young ones.

• **Excretion**: Removal of metabolic waste. Plants store waste in leaves (which fall off) or vacuoles; animals excrete through kidneys, skin, or lungs.

• **Growth and Development**: All living organisms grow—plants show unlimited growth; animals show limited growth that stops at maturity.

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Formulas / Key Facts

| Life Process | In Plants | In Animals | |--------------|-----------|------------| | Nutrition | Photosynthesis (autotrophic) | Ingestion of food (heterotrophic) | | Respiration | Through stomata and lenticels | Through lungs, gills, or skin | | Excretion | Stored in vacuoles/shed leaves | Through kidneys, skin, lungs | | Movement | Limited (tropisms, nastic movements) | Locomotion using limbs, fins, wings | | Reproduction | Seeds, spores, vegetative propagation | Eggs (oviparous) or live birth (viviparous) |