Biology

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high importance~2 Q in Tier 14 formulas⚡ 12 shortcuts6 subtopics

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Branches of biology and ecology

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⏱ 6 min read🧩 6 question types🎯 20 practice Q

The idea in one minute

Branches of study (-ologies)

Branch	Study of	Branch	Study of
Ornithology	Birds	Entomology	Insects
Ichthyology	Fish	Herpetology	Reptiles and amphibians
Mycology	Fungi	Phycology	Algae
Cytology	Cells	Histology	Tissues
Genetics	Heredity	Taxonomy	Classification
Palaeontology	Fossils	Anthropology	Humans / human cultures
Pathology	Diseases	Virology	Viruses
Cardiology	Heart	Nephrology	Kidneys
Dermatology	Skin	Haematology	Blood
Oncology	Cancer	Ophthalmology	Eyes
Osteology	Bones	Neurology	Nervous system
Pomology	Fruits	Olericulture	Vegetables
Floriculture	Flowers	Horticulture	Garden crops

Culture / rearing

Term	Rearing of
Apiculture	Honey bees
Sericulture	Silkworms (silk)
Pisciculture	Fish
Viticulture	Grapes
Lac culture	Lac insects

Ecology

'Ecology' was coined by Ernst Haeckel; 'ecosystem' by A.G. Tansley (1935).
A food chain runs: producers (green plants) → primary consumers (herbivores) → secondary consumers → tertiary consumers. Decomposers (bacteria, fungi) recycle nutrients.
10% law (Lindeman): only about 10% of energy passes to the next trophic level; the rest is lost mostly as heat. Hence food chains are short (usually 3–5 levels).
The pyramid of energy is always upright; the pyramid of biomass in a pond can be inverted.
Biomagnification — non-degradable chemicals like DDT and mercury increase in concentration at higher trophic levels.
The flow of energy is one-way; nutrients cycle.

Branches of study — the -ology table

Branch	Studies
Ornithology	Birds
Entomology	Insects
Ichthyology	Fishes
Herpetology	Reptiles and amphibians
Mycology	Fungi
Virology	Viruses
Cytology	Cells
Histology	Tissues
Oncology	Cancer
Cardiology	Heart
Ophthalmology	Eye
Anthology	Flowers
Trap pair: entomology = insects (not etymology — words). Apiology = bees; malacology = molluscs.

Culture words — rearing living things

Apiculture = honeybees (honey). Sericulture = silkworms (silk). Pisciculture = fish. Aquaculture = water organisms. Horticulture = garden plants. Floriculture = flowers. Vermiculture = earthworms. Silviculture = forest trees. Poultry farming = fowl. India's colour revolutions: Green — food grain (M.S. Swaminathan in India; Norman Borlaug worldwide), White — milk (Verghese Kurien, Operation Flood), Blue — fish, Yellow — oilseeds.

Ecosystem and the 10% law

An ecosystem = living community + its physical surroundings. Food chain: producers (green plants) → herbivores (primary consumers) → carnivores (secondary, tertiary). Lindeman's 10% law: only about 10% of energy passes to the next level — 10,000 J of producers gives 1,000 J to herbivores, 100 J to small carnivores, 10 J to big ones. Decomposers (bacteria, fungi) recycle nutrients. A food web is interlinked chains; bioaccumulation makes toxins concentrate up the chain.

Cycles, conservation, biodiversity

Nitrogen cycle: soil nitrogen → plants (via Rhizobium bacteria in legume root nodules) → animals → back to soil. Carbon cycle ties respiration, photosynthesis and fuels. Conservation firsts: Jim Corbett National Park (1936) — India's first; Project Tiger (1973); Chipko movement (1973) — villagers hugging trees. IUCN Red List ranks threatened species (extinct → vulnerable → least concern); the Red Data Book records them. Ramsar sites = wetlands.

Pollution and milestones

Air: CO, SO₂, NOₓ, particulates; BOD (biochemical oxygen demand) measures water pollution — higher BOD, dirtier water. Silent Spring (Rachel Carson, 1962) warned against pesticides like DDT. Cloning milestone: Dolly the sheep (1996), first cloned mammal. Norman Borlaug = father of the Green Revolution; Salim Ali = the birdman of India.

Question types you will see

Each type: how to recognise it, the method step by step, and one question to try.

Type 1very common4 practice Q

Branch of study → organism

How to spot it:

'Ornithology is the study of…', 'entomology / ichthyology / herpetology / mycology', 'study of cancer / heart / eye', odd-one-out among -ology branches.

Method

Animals: ornithology–birds, entomology–insects, ichthyology–fishes, herpetology–reptiles+amphibians, apiology–bees.
Micro/inner: mycology–fungi, virology–viruses, cytology–cells, histology–tissues.
Medical: oncology–cancer, cardiology–heart, ophthalmology–eye, nephrology–kidney.
Kill the trap: entomology is insects, NOT etymology (words).

Why it works:

root + animal = answer; cluster-learn five at a time.

Try this

Entomology is the study of —

Show solution

Insects. Don't confuse with etymology (word origins). Ichthyology is fish; ornithology, birds.

Type 2very common3 practice Q

Culture/rearing word ↔ creature

How to spot it:

'Sericulture is associated with…', 'apiculture / pisciculture / vermiculture', 'which culture is for flowers', match-the-column of cultures.

Method

Apiculture–bees (honey); sericulture–silkworms (silk); pisciculture–fish; aquaculture–water organisms.
Horticulture–gardens; floriculture–flowers; vermiculture–earthworms; silviculture–trees.
Root logic helps: api- (bee), seri- (silk), pisci- (fish), vermi- (worm), silvi- (forest).

Why it works:

each word is Latin root + culture; decode the root when unsure.

Try this

Sericulture is the rearing of —

Show solution

Silkworms for silk production. Apiculture keeps bees, pisciculture fish.

Type 3very common3 practice Q

Food chain and the 10% law (computed)

How to spot it:

'Producers trap 10,000 J, energy at the third level', 'the 10% law was given by…', 'which are primary consumers', 'energy flow is always…'.

Method

Chain: producers → primary (herbivores) → secondary → tertiary; energy flows one way, decreasing.
Lindeman's 10% law: keep chopping a zero — 10,000 J → 1,000 J (2nd level) → 100 J (3rd) → 10 J (4th) → 1 J (5th).
'Third trophic level' = second consumer = small carnivores: 100 J from a 10,000 J base. Count levels, not names.

Try this

Producers store 10,000 J. By the 10% law, the energy reaching the third trophic level is —

Show solution

10,000 → 1,000 (herbivores) → 100 J (small carnivores). Each step keeps only a tenth.

Type 4common3 practice Q

Conservation firsts and biodiversity

How to spot it:

'First national park of India', 'Project Tiger was launched in…', 'Chipko movement', 'IUCN Red List', 'which bacteria fix nitrogen in legumes'.

Method

Jim Corbett (1936) = first national park; Project Tiger (1973); Chipko movement (1973, tree-hugging, Sunderlal Bahuguna).
IUCN Red List + Red Data Book = threatened species records; Ramsar = wetlands.
Rhizobium in legume root nodules fixes atmospheric nitrogen — the natural fertiliser.

Try this

India's first national park (1936) is —

Show solution

Jim Corbett National Park (Uttarakhand; originally Hailey). Project Tiger began there in 1973.

Type 5common3 practice Q

Colour revolutions and scientists

How to spot it:

'White Revolution is related to…', 'father of the Green Revolution', 'who is the birdman of India', 'Blue Revolution'.

Method

Green–food grain (M.S. Swaminathan in India; Norman Borlaug worldwide); White–milk (Verghese Kurien, Operation Flood); Blue–fish; Yellow–oilseeds.
Salim Ali = birdman of India; Rachel Carson = Silent Spring (DDT warning); Dolly the sheep (1996) = first cloned mammal.
Pair the colour with the produce first, then attach the name.

Try this

The White Revolution (Operation Flood) in India is associated with —

Show solution

Milk production, led by Verghese Kurien (Amul). Green was food grain, Blue was fish.

Type 6common2 practice Q

Ecology basics and pollution measures

How to spot it:

'BOD measures…', 'which organisms are decomposers', 'ozone layer position', 'food web is…', 'bioaccumulation'.

Method

BOD (biochemical oxygen demand) — higher value = more polluted water.
Decomposers = bacteria and fungi recycling nutrients; food web = many interlinked food chains.
Pollutants like DDT bioaccumulate up the food chain — top predators get the most.
Ozone layer sits in the stratosphere; CFCs were its destroyer (Montreal Protocol, 1987).

Try this

BOD (biochemical oxygen demand) of a water sample indicates —

Show solution

Its pollution level: more organic waste means bacteria consume more oxygen, so a HIGHER BOD means dirtier water.

Formula sheet

10% law of energy transfer

E_{n} = E_{1} \times (0.1)^{\,n-1}

E₁ = energy at the producer level, n = trophic level

Shortcuts that save time

⚡ Culture words by root

Api = bee (apiary), Seri = silk, Pisci = fish (Pisces), Viti = vine/grapes, Pomo = fruit (pomegranate), Olera = vegetables.

Example

Sericulture is the rearing of?

Show solution

Silkworms.

⚡ Study-of roots

Ornitho = bird, Ento = insect, Ichthyo = fish, Herpeto = creeping animals, Myco = fungus, Phyco = seaweed/algae, Onco = tumour, Nephro = kidney.

Mistakes to avoid

Where most students lose marks on this subtopic.

Mistake 01

Confusing entomology (insects) with etymology (word origins).

Mistake 02

Mixing up pisciculture (fish) and pomology (fruits).

Mistake 03

Saying energy cycles in an ecosystem — it flows one way; nutrients cycle.

Quick revision

Read this the night before the exam.

Ornithology–birds, entomology–insects, ichthyology–fish, herpetology–reptiles, mycology–fungi, oncology–cancer.
Apiculture–bees, sericulture–silk, pisciculture–fish, vermiculture–worms, silviculture–trees.
10% law (Lindeman): 10,000 → 1,000 → 100 → 10 J up the chain.
Corbett 1936 first park; Project Tiger 1973; Chipko 1973; Dolly the sheep 1996.
Green–Swaminathan/Borlaug, White–Kurien, Blue–fish; Rhizobium fixes nitrogen in legume nodules.

Practice: 20 questions

Sets of 10, mixed across the question types above. Every answer has a step-by-step explanation.

Topic test · 10 questions

Suggested time 3 min · wrong answers go to your mistake notebook automatically.

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