Analogy

Analogy means finding a similar relationship between two pairs of words or numbers. The question gives you one complete pair and asks you to find the missing word in the second pair that maintains the same relationship.

Common relationship types in SSC CGL:

1. Tool : User (Scalpel : Surgeon)
2. Part : Whole (Chapter : Book)
3. Product : Raw Material (Bread : Wheat)
4. Animal : Sound (Dog : Bark)
5. Worker : Workplace (Doctor : Hospital)
6. Word : Antonym/Synonym
7. Male : Female (Bull : Cow)
8. Young one (Cat : Kitten)

Memory Trick - ALWAYS identify the exact relationship first, then apply it strictly to the second pair. Do not choose an answer that has a loose connection — SSC prefers precise relationships.

Walk into any school garden in India and you are looking at a complete ecosystem in miniature. The roses, the grass under your feet, the grasshoppers jumping ahead of your shoes, the sparrows watching from the fence, the cat dozing in the sun, the earthworms hidden in the soil, the fungi creeping over a dead log — every one of them has a fixed role. Learning to sort these roles is the single most important skill in NCERT Class 10's chapter on Our Environment, because every food chain, food web and energy-flow diagram you will ever draw starts from it.

Definition: An ecosystem is a self-sustaining unit of nature in which living organisms (biotic components) interact among themselves and with the non-living surroundings (abiotic components).
Definition: Biotic components are all the living organisms — plants, animals, fungi and microorganisms — in an ecosystem.
Definition: Abiotic components are the non-living, physical and chemical factors — sunlight, soil, water, air, temperature — that support life.

Step 1 — Separate the biotic from the abiotic

The first cut is always living versus non-living. In our garden problem the abiotic players are soil, sunlight and rainwater. These three do not eat, breathe or reproduce, but no living thing can survive without them. Sunlight is the primary energy input, water is the medium for every chemical reaction inside cells, and soil supplies minerals and physical support for roots.

The biotic players are rose plants, grass, grasshoppers, sparrows, the cat, earthworms and fungi. They all carry out the seven life processes — nutrition, respiration, transport, excretion, control, reproduction, growth — but the way each obtains its food is different. That difference is the basis of the next, more important classification.

Step 2 — Sort the biotic items by how they get food

Definition: Producers (autotrophs) are organisms that make their own food from simple inorganic substances using sunlight (photosynthesis) or chemicals.
Definition: Consumers (heterotrophs) are organisms that cannot make their own food and depend, directly or indirectly, on producers.
Definition: Decomposers (saprotrophs) are organisms that break down dead organic matter into simple substances that return to the soil and air.

In our garden:

• Producers: rose plants and grass. They contain chlorophyll, trap solar energy and convert CO2 + water into glucose. Without them the whole ecosystem would starve in days.
• Primary consumers (herbivores): the grasshoppers. They feed directly on grass and are the first link that moves energy from the plant world into the animal world.
• Secondary consumers (small carnivores): the sparrows. They eat grasshoppers, so they are one feeding step removed from plants.
• Tertiary consumer (top carnivore): the cat. It eats sparrows, sitting at the top of this short food chain.
• Decomposers: the earthworms and fungi. Earthworms swallow soil rich in dead leaves and excrete nutrient-rich castings; fungi secrete enzymes that digest the dead log from the outside. Both convert complex organic matter into simple nutrients that plants can re-absorb.

So the food chain here is: Grass → Grasshopper → Sparrow → Cat, with rose plants as another producer and earthworms and fungi quietly cleaning up at every level.

Step 3 — Follow the energy and the nutrients

This is where NCERT wants you to think a step deeper. Energy flows in one direction through the chain — sunlight is captured by producers, only about 10% passes to the next trophic level (the famous 10% law of Lindeman), and the rest is lost as heat during respiration. That is why food chains rarely have more than four or five steps: there simply is not enough energy left at the top to support a longer chain.

Nutrients, however, cycle. Carbon, nitrogen and minerals locked inside the cat's body do not stay there forever. When the cat dies, the same earthworms and fungi will break its body down and release those elements back into the soil, where grass and roses will pull them up again. This loop is what makes the ecosystem self-sustaining — sunlight keeps pouring in, and the same matter keeps recirculating.

Why it matters: Every question on food chains, food webs, biological magnification and biogeochemical cycles in your Board paper rests on this single classification. Get producer–consumer–decomposer right, and the rest is just labelling.

Real-world example: A typical north-Indian kitchen garden in a village like Naya Raipur shows this perfectly. Sunlight and monsoon rain feed tulsi, methi and palak (producers). Caterpillars and aphids (primary consumers) chew the leaves. House sparrows and bulbuls (secondary consumers) snap up the caterpillars. A neighbourhood mongoose or cat (tertiary consumer) hunts the birds. Beneath the soil, earthworms and Trichoderma fungi convert fallen leaves and cattle dung into the rich kala mitti that the next crop of palak depends on. Pull out any one group and the garden collapses.

Common misconception: Many students think decomposers are "useless" or just "things that rot food". In reality decomposers are the most essential group — without them, dead bodies and fallen leaves would pile up, nutrients would stay locked in corpses, and the soil would run out of minerals within a few seasons. A forest without earthworms and fungi would die faster than a forest without tigers.

Question: A small park contains mango trees, caterpillars, mynas, a stray dog, mushrooms growing on a fallen branch, soil, air and morning sunshine. Classify each.

Solution:
Step 1: Abiotic — soil, air, sunshine.
Step 2: Producers — mango trees (autotrophs, photosynthesis).
Step 3: Primary consumer (herbivore) — caterpillars (eat mango leaves).
Step 4: Secondary consumer (carnivore) — mynas (eat caterpillars).
Step 5: Tertiary consumer (carnivore) — stray dog (could eat mynas or scavenge).
Step 6: Decomposer — mushrooms (fungi breaking down the dead branch).
Conclusion: Every organism fits one trophic role, and together with the abiotic factors they form the park ecosystem.

For number analogies in SSC CGL, the most common patterns are:

1. Square pattern: 4 : 16 :: 7 : 49 (n : n²)
2. Cube pattern: 2 : 8 :: 3 : 27 (n : n³)
3. Double/Half: 6 : 12 :: 9 : 18
4. Prime pattern: 3 : 9 :: 5 : 25
5. Difference pattern: 36 : 6 :: 100 : 10 (n² : n)
6. Sum of digits: 123 : 6 :: 231 : 6
7. Product pattern: (a × b) forms the relationship

Formulas:

• If a : a² then ? : ?² → answer is b²
• If a : (a+k) then b : (b+k)
• If a : √a then b : √b

Memory Trick — Try squaring, cubing, or finding the difference between the two numbers in the first pair first. One of these will almost always reveal the pattern for SSC.

Quick-revision notes for Analogy — the must-know points for SSC CGL Tier-I/II.

• Analogy tests the relationship between a given pair and asks you to reproduce it in a second pair (A:B :: C:?).
• Common relations: synonym, antonym, part-whole, worker-tool, cause-effect, category-example, and degree/intensity.
• Letter analogies: track the gap pattern between letters (e.g. AB:CD means +2 to each) and mirror it exactly.
• Number analogies: look for +, −, ×, ÷, square, cube, or "next prime" relationships between the paired numbers.
• Build a clear "connecting sentence" for the first pair, then test which option fits the same sentence for the second pair.
• Watch the order — Doctor:Hospital is not the same as Hospital:Doctor; keep the direction of the relationship identical.

Cover the answer, recall, then check. 6 cards on the must-know Analogy facts for SSC CGL.

Q1. Pen : Write :: Knife : ?
A1. Cut — the tool-to-function relationship (a pen is used to write, a knife to cut).

Q2. Complete the letter analogy AZ : BY :: CX : ?
A2. DW — first letter +1 (A→B→C→D), second letter −1 (Z→Y→X→W).

Q3. 4 : 64 :: 5 : ?
A3. 125 — the relation is cube (4³ = 64, so 5³ = 125).

Q4. What relationship links Cobbler : Leather?
A4. Worker-to-material: a cobbler works with leather (like carpenter:wood).

Q5. Hot : Cold :: Big : ?
A5. Small — an antonym (opposite) relationship.

Q6. Best method to fix an analogy relationship quickly?
A6. Frame a short sentence linking the first pair, then apply the identical sentence to the second pair to pick the answer.