NCERT Solutions for Class 9 Science Chapter 12 Patterns in Life Diversity and Classification (PDF) – 2027

Biodiversity is the immense variety of living organisms on the Earth — from microscopic organisms invisible to the naked eye to giant trees, from glowing jellyfish to soaring eagles — living in countless forms and habitats, from the snow-clad Himalayas to the coral reefs of the Andaman Sea. Every organism plays a role in keeping nature stable: algae release oxygen, fungi and bacteria decompose wastes, birds, bees and bats pollinate flowers, and plants make food.

Grouping organisms by their shared features makes their huge diversity easy to study. Just as books in a library arranged by subject and author can be found quickly, organisms grouped by similarities and differences can be identified, compared and studied systematically. Once we know an organism’s group we already know many of its features, and the similarities within a group show how its members are related — they have evolved from common ancestors.

Plants and animals are classified on the basis of their shared characteristics — scientists look first at broad, easily visible features and then at more detailed ones. The criteria used are: external features (shape, size, body organisation); mode of nutrition; internal structures (skeleton, organs, tissues); cell structure (unicellular or multicellular, prokaryote or eukaryote, cell wall); ecological role; reproduction; and genetic similarity (DNA). Plants are then grouped by body organisation, vascular tissue, seeds and flowers; animals first by the presence or absence of a notochord.

Classification helps farmers identify organisms correctly, and correct identification is the first step in solving most farm problems. It helps to (1) tell harmful pests from useful insects that protect crops; (2) choose and conserve crop varieties with useful traits such as drought tolerance, pest resistance and growth in nutrient-poor soils — this diversity reduces the risk of crop failure and strengthens food security; (3) use helpful microbes, such as Rhizobium and the fungi and bacteria that turn waste into manure; and (4) protect pollinators such as bees, birds and bats.

The organisms are grouped by the time at which they are active. The left (lit) half shows the forest by day, with day-active animals such as the peacock, eagle, spotted deer, tiger and butterflies; the right (dark) half shows it at night, with night-active animals such as the owl, bats, slender loris, porcupine and fireflies. Within each half the animals are also spread out by where they live — in the air, on trees, on the forest floor, and in or near water.

Animals in Fig. 12.2 (numbers as in the redrawn figure):
By day (left half): 1 eagle, 2 butterfly, 3 dragonfly, 4 peacock, 5 langur, 6 leopard, 7 spotted deer (chital), 8 tiger, 9 sloth bear, 10 lion-tailed macaque, 11 small perching birds, 12 hare.
At night (right half): 13 bats, 14 owl, 15 python, 16 slender loris, 17 a small ringed-tailed mammal on the trunk (civet-like), 18 porcupine, 19 civet, 20 fireflies, 21 frog, 22 crocodile.

They are seen in different parts of the forest — high in the air, near the ground, on trees, on the forest floor, and in or near water:

Fill Table 12.1 with one row per organism. Here is a completed sample using animals from Fig. 12.2 (the book’s own owl row is kept as the first line).

The same animals of Fig. 12.2 are grouped here by several different criteria. Notice how the members of the groups change every time.

Yes, very likely. Similar features in organisms suggest that they have evolved from a common ancestor, because features are inherited — passed from parents to offspring through DNA. The deeper and more detailed the shared feature (for example the same bones in the forelimbs of a bat, a whale and a human, or similar DNA), the stronger the evidence. But a similar look alone can mislead: a shark and a dolphin are both streamlined for water, yet one is a fish and the other a mammal.

Species are not spread evenly through a forest; each is found where its particular needs are met. In Pakke, the four hornbill species live in different parts of the forest depending on tree size and fruit availability, because they nest only in large, old trees with suitable cavities and feed on specific fruits. Closely linked are: large old trees and hornbills (nest cavities), fruiting trees and hornbills (hornbills eat the fruits and disperse the seeds), and predators, prey and plants, such as tiger – deer – grasses.

Classifying the four hornbills as separate species shows a pattern of biodiversity that the single name “hornbill” would hide. It lets scientists count species (nearly 300 bird species in Pakke out of about 1,300 in India), see that each species uses different trees, fruits and parts of the forest, ask precise questions about how species are distributed and linked, and plan conservation for each species — for example, protecting the large old nest trees that a particular hornbill needs.

By classifying and naming them systematically. (1) Every species is placed in a hierarchy — kingdom, phylum, class, order, family, genus, species — which works like an address, so it can be located and compared. (2) Each species has one scientific (binomial) name used all over the world. (3) Scientists keep records — identification keys, field guides, museum specimens, photographs, call recordings and DNA data — against which any new individual can be checked; one that matches nothing known may be a new species.

Scientists use fine, constant features rather than general appearance: (1) the casque (horn-like growth on the bill) and the bill — their size, shape and colour; (2) plumage colour and pattern, e.g. the reddish neck of the Rufous-necked Hornbill and the black-and-white body of the Oriental Pied Hornbill; (3) body size — the Great Hornbill is the largest, the Oriental Pied the smallest; (4) the call of each species; (5) ecological features — the fruits eaten, the nest trees used and the part of the forest occupied; and (6) DNA comparison.

The hornbills would lose their only nesting sites and stop breeding, and the effect would spread through the forest. Hornbills nest only in cavities of large, old trees, so their numbers would fall. With fewer hornbills, fewer seeds of fruiting trees would be dispersed, so fewer new trees would grow. Owls, parakeets, squirrels, bats and insects that also use tree cavities would lose their homes. As the chapter says, when one species disappears, others that depend on it may also decline and eventually disappear.

Fig. 12.5 works like a decision tree. Start at the top with any organism and answer one question at each branch — cell type, then level of organisation, then cell wall, and finally wall material and mode of nutrition. After at most four questions you reach one of the five kingdoms: Monera, Protista, Fungi, Plantae or Animalia.

Reading Fig. 12.5 from the top down, the concept map turns on five criteria:

1. Cell type — prokaryote (primitive nucleus, no bounding membrane) or eukaryote (membrane-bound nucleus).
2. Level of organisation — unicellular or multicellular.
3. Cell structure — cell wall present or absent, and if present, made of chitin or cellulose.
4. Mode of nutrition — autotrophic (makes its own food by photosynthesis) or heterotrophic (depends on others for food).
5. Ecological role — producer, consumer or decomposer.

All four listed criteria appear in the concept map; the map applies them in the order cell type → level of organisation → cell structure → mode of nutrition. The only item on my list that is not in the four given is ecological role (producer / consumer / decomposer), which Fig. 12.5 prints alongside mode of nutrition at the last fork.

Observation: both are extremely small single cells in which no nucleus can be seen, even under high power.

What you should see:

• Bacteria — extremely small, stained dots, rods or spirals. Nothing inside them is resolvable: no nucleus, no chloroplast, no visible organelles. Often they lie in chains or clusters.
• Cyanobacteria — noticeably larger, blue-green, usually as unbranched filaments of cells joined end to end (for example Nostoc, Oscillatoria). The colour is spread through the whole cell, not packed into chloroplasts.

Fig. 12.6 shows the members of Kingdom Monera. Match what is on your slide to the figure point by point.

Bacteria and cyanobacteria are both single-celled prokaryotes — they have no true (membrane-bound) nucleus — so both are placed in Kingdom Monera. Bacteria look like tiny dots, rods, commas or spirals; cyanobacteria are larger, blue-green and often joined in chains (filaments). Bacteria are found everywhere — soil, water, air, hot springs and even inside our bodies. Some cause diseases, but many are useful, like Lactobacillus and Rhizobium. Cyanobacteria make their own food by photosynthesis.

Follow the seven steps as given, keep the covered bottle undisturbed for a week, and then observe one drop under the microscope. The dead grass feeds bacteria, and protists from the pond water multiply by feeding on them, so after a week the drop is full of tiny moving organisms. Caution: the infusion may smell bad — wear a lab coat, mask and gloves, and discard the infusion only after autoclaving.

Yes, moving organisms can be seen in the drop. Comparing them with Fig. 12.7: Amoeba has no fixed shape and moves slowly by pushing out pseudopodia (false feet); Paramecium is slipper-shaped and swims fast using fine hair-like cilia; Euglena is spindle-shaped and green, with a red eyespot, and swims with one long flagellum. All three are single-celled eukaryotes, so they belong to Kingdom Protista.

A single-celled organism is very small, so its one cell can carry out all the life processes by itself. Its whole surface is in contact with the surroundings, so oxygen, food and wastes move in and out directly by diffusion, and different parts of the cell do different jobs — for example, in Amoeba and Paramecium food vacuoles digest food, the contractile vacuole removes extra water, and pseudopodia or cilia help in movement and feeding. A large multicellular body cannot be supplied by diffusion alone, so its work is divided among billions of specialised cells, tissues and organs.

These white-green patches are lichens. A lichen is a symbiotic association of two organisms — an autotrophic alga, which photosynthesises and provides food, and a heterotrophic fungus, which provides protection. Village elders recognise the patches as a sign of a pollution-free environment: lichens change their colour with air pollutants, so researchers use them as natural bioindicators of air quality. Some lichens (patthar ke phool) are used as a spice, some as medicines and some for dyes; since some are poisonous, they must be identified correctly.

Collect a small piece of a damp green moss mat in a watch glass and examine it with a hand lens.

What the hand lens shows:

• The whole plant is tiny — usually only 1 to 3 cm tall.
• There are thin, hair-like threads at the base that hold it to the surface. These are rhizoids — root-like, but not true roots.
• Above them, in a moss, is a slender stem-like axis with very small leaf-like structures spirally arranged around it. In Marchantia (a liverwort) there is no such axis at all — the body is a flat green ribbon lying on the soil.
• You may see fine stalks rising from the mat with a capsule at the tip — the spore-producing part.

The drop of water does two things: it keeps the specimen alive, and it makes the very thin leaf-like structures transparent so light passes through them.

What you should see under the dissecting microscope:

• The “leaf” is usually one cell thick, so you can see the individual cells and the green chloroplasts inside them without any staining or sectioning.
• There are no veins — some mosses have only a thickened strip down the middle, but there is no network of veins carrying xylem and phloem.
• The rhizoids are simple threads, not branched absorbing roots.
• The whole plant may spring back and unfold as it takes up water — a dry moss revives in minutes.

A bryophyte “leaf” is not a true leaf at all. It is a flat, usually one-cell-thick green flap with no veins (no xylem or phloem), no stalk and no waxy cuticle. An ordinary leaf from a neem or mango tree is many cells thick, has a midrib with a branching network of veins, a petiole, and a waxy cuticle with stomata.

The fern in Fig. 12.11a has, for the first time in the plant kingdom, true roots, a true stem and true leaves. Thallophytes had none of these — only a thallus, an undifferentiated body. Bryophytes had rhizoids and merely stem-like and leaf-like structures. The fern has the real organs.

Through specialised transport tissue running from root to leaf tip — xylem carrying water upward and phloem carrying food. This is the “one possible explanation” the chapter offers, and it is the correct one.

What the two tissues do:

• Xylem — hollow, dead, thick-walled tubes joined end to end. It carries water and dissolved minerals from the roots upwards, and its lignified walls also stiffen the stem, which is what allows the plant to stand up.
• Phloem — living tubes that carry food made in the leaves to every other part, including downwards to the roots, which cannot photosynthesise.

Cut a thin cross section of a fern stem and look at it under a microscope. If the explanation is right, the cut surface must show the pipes; if the fern had no transport tissue, the section would be uniform.

What you find: Fig. 12.11b shows the result — the cross section carries vascular tissues, xylem and phloem, which transport water and food respectively throughout the plant. The prediction is confirmed.

The sunflower is a dicot angiosperm — the most advanced plant group in this chapter. Its stem cross section, from Chapter 3, is arranged as follows:

• An outer epidermis with a cuticle.
• A zone of cortex below it.
• The vascular bundles arranged in a ring, evenly spaced, each bundle with xylem towards the inside and phloem towards the outside.
• Between the xylem and phloem of each bundle, a thin strip of lateral meristem (cambium) — a layer of dividing cells.
• A large central pith.

Both stems have xylem and phloem, but the vascular tissue is arranged differently. (1) In the fern stem (Fig. 12.11b) the xylem lies in the centre of the bundle and the phloem surrounds it on all sides; in the sunflower stem each bundle has phloem towards the outside and xylem towards the inside, and the bundles form a regular ring around the pith. (2) The fern has no lateral meristem (cambium) between the xylem and phloem, so it cannot add new vascular tissue; the sunflower has one. (3) The fern’s xylem has mainly narrow tracheids; higher plants also have wide vessels.

Features that reduce dependence on water: true roots that reach water deep in the soil, vascular tissue (xylem and phloem) that carries water and food to all parts, and a waxy cuticle on the leaves that reduces water loss — as in pteridophytes. Features that still need moist conditions: the male reproductive cells must swim to the female cells, so fertilisation needs water; and there are no seeds — spores have no stored food or protective coat, so they can grow only in damp places.

In a tall plant the roots and the leaves are far apart. Roots absorb water and minerals but cannot make food; leaves make food but cannot take water from the soil. Over such long distances, diffusion from cell to cell is far too slow. So tall plants need specialised transport tissues: xylem carries water and minerals from the roots up to the leaves, and phloem carries food from the leaves to all other parts, including the roots. The thick-walled xylem also gives the stem the strength to stand upright.

Seeds protect the developing embryo and contain stored food, so the young plant can survive dry or cold periods and grow when conditions are right; and seed plants (gymnosperms and angiosperms) do not need water for fertilisation. So they can live on dry land and even in cold, dry regions, like pines. Fruits enclose and protect the seeds and help spread them to new places through insects, birds, animals, wind or water, so the young plants do not compete with the parent. This is why angiosperms occupy the widest range of environments and are the most diverse plant group.

Sort the leaves by venation — that single character separates monocots from dicots reliably.

How the structures help them survive: the long, narrow, parallel-veined leaves of monocots such as grasses bend in the wind without tearing, and grasses grow again from the leaf base after grazing; the broad, net-veined leaves of dicots trap more sunlight, which helps in shady places; thick, waxy or needle-like leaves reduce water loss in dry places; and large, thin leaves (banana) are found where water is plentiful.

Read the five groups in order and watch for the one problem each solves. Set out that way, Table 12.3 stops being a list and becomes a sequence.

Here is Table 12.3 completed. The book’s own entries are kept and the blank lines are filled in.

No, sponges cannot survive on land. A sponge has no tissues or organs — no mouth, gut, gills or protective covering. It depends on water flowing continuously through the pores in its body, which brings food particles and oxygen directly to its cells and carries wastes away. On land there is no water current, so the sponge would get no food or oxygen, could not remove its wastes, and its porous body would quickly dry out.

Limitations of a single opening: (1) food cannot be taken in while waste is being thrown out through the same opening, so feeding cannot be continuous; (2) digestion happens in one chamber, so there are no separate regions for the different stages of digestion and absorption; (3) undigested waste can mix with newly taken food, so absorption is less efficient. Such a body works only for small, thin animals; a gut with two openings (mouth and anus), as in roundworms, removes these limitations.

Segmentation allows greater flexibility and more precise control of movement. Watching an earthworm shows that its body does not move as one block: waves of contraction pass along it, some segments becoming long and thin while others become short and thick, because each segment has its own muscles and fluid-filled body cavity, and the nerve cord controls them in sequence. Advantages: flexible, wave-like movement for burrowing; precise local control; damage to one segment does not disable the whole body; and segments can become specialised for different jobs, as in arthropods.

The hard outer covering (exoskeleton) provides protection, reduces water loss and supports powerful muscles. It shields the soft body from predators and injury; its waxy layer stops the body from drying out, so arthropods can live in dry and exposed places where soft-bodied animals like earthworms cannot; and the muscles attached to its inner side get a firm base to pull on, giving strong, precise movement of the jointed legs, wings and mouthparts.

The beetle’s hard exoskeleton helps it survive in three ways. (1) Protection — it acts as armour against predators and injury. (2) Less water loss — its waxy covering stops the body from drying out, so the beetle can live in dry, exposed places, while the soft-bodied earthworm must stay in moist soil. (3) Support for powerful muscles — muscles attached to the inside of the rigid covering give strong, precise movement for walking, digging and flying.

Forests rich in biodiversity act as physical, biological and chemical barriers. Physical: dense mangrove forests broke the force of the 1999 super cyclone in Orissa (Odisha) — villages with more mangroves suffered less destruction. Biological: in the Western Ghats, rich forest diversity lowers the risk of tick-borne Monkey Fever (Kyasanur Forest Disease), because many of the animals that ticks feed on are hosts in which the virus cannot multiply. Chemical: diverse microbes in forest soils and roots break down pollutants, and mangrove soils trap sediments and heavy metals, keeping rivers and seas cleaner.

Classification is a nested hierarchy: it starts from very broad groups and moves to smaller, more specific ones, and at each lower level the organisms share more features in common. Every lower group lies entirely inside the group above it.

No — biodiversity includes more than the variety of organisms. It covers (1) species diversity — the number and variety of species (e.g. nearly 300 bird species in Pakke); (2) genetic diversity within a species — e.g. the many crop varieties that farmers conserve for drought tolerance or pest resistance; and (3) diversity of habitats and ecosystems — mountains, deserts, rainforests, plateaus, coasts, coral reefs and wetlands such as the phumdis of Loktak Lake. It also includes the interactions among organisms and with their surroundings that keep ecosystems working.

I would observe its features in the order used in Fig. 12.5, from the most basic to the finest, because each observation narrows down the group: (1) cell type — is there a true nucleus? (none → Monera); (2) number of cells — one or many? (one cell with a nucleus → Protista); (3) cell wall — absent (Animalia), made of chitin (Fungi) or of cellulose (Plantae); (4) mode of nutrition — is it green and making its own food, or depending on others? Then (5) its body organisation and symmetry, whether it has a notochord or backbone, how it moves and feeds, and how it reproduces.

Because DNA carries the instructions for the growth and functioning of every cell and is passed from parents to offspring. All visible features are the result of these instructions, so comparing DNA compares organisms at their very base; organisms with similar DNA are considered to share a common ancestry. DNA shows true relationships even when appearance misleads (a dolphin looks like a fish but is a mammal), separates organisms that look alike (such as many bacteria), and can measure how closely two organisms are related. Such studies led Carl Woese to propose the three domain system (1977).

Climate change alters the temperature and rainfall to which each species is adapted. When conditions change faster than species can adapt or move: (1) habitats are lost or shift — mountain and endemic species have nowhere else to go; (2) the timing of flowering, breeding and migration goes out of step, e.g. between plants and their pollinators; (3) more cyclones, droughts and floods destroy habitats such as the phumdis; (4) warmer seas bleach coral reefs. When one species disappears, others that depend on it may also decline and disappear, so biodiversity is reduced.

Suggestions to save the phumdis and the Sangai deer: (1) let the water level of Loktak Lake rise and fall naturally, so that the phumdis can touch the lake bed and stay healthy; (2) stop sewage, fertiliser run-off and silt from entering the lake; (3) protect Keibul Lamjao National Park strictly — no cutting or burning of phumdis, no poaching — and add more habitat; (4) involve local fishing communities, with other livelihoods and eco-tourism; (5) count and monitor the deer regularly; (6) keep a captive-breeding group as a safety population; (7) spread awareness about the Sangai, Manipur’s state animal.

(ii) Body with jointed legs. Jointed legs (appendages) are the defining feature of arthropods such as insects; an earthworm has no legs at all. The other options cannot confirm it: both animals are bilaterally symmetrical and segmented, and a cylindrical body is a feature of the earthworm.

(iii) Presence of a cell membrane. The intended point is that a sponge cell is bounded by a cell membrane and has no cell wall — and in Fig. 12.5, absence of a cell wall is exactly the fork that leads to Animalia.

(a house crow and a garden lizard): the crow has feathers, forelimbs changed into wings, a toothless beak and a constant body temperature, and it lays hard-shelled eggs in a nest. The lizard has dry scales, four walking legs and jaws with teeth; it basks in the sun to warm its body and lays leathery eggs in the soil. Both have a backbone, so both are vertebrates in Kingdom Animalia; but body covering, limbs and reproduction place the crow among birds and the lizard among reptiles.

Cellular organisation is a more fundamental basis because it applies to all living organisms, while xylem and phloem are found only in some plants. Every organism is made of cells, so questions such as “prokaryote or eukaryote?” and “unicellular or multicellular?” can be asked of bacteria, protists, fungi, plants and animals alike, and they divide all of life into large groups at the very first step. Xylem and phloem are absent in bacteria, protists, fungi and animals, and even in algae and bryophytes, so they can separate groups only within the plant kingdom — lower down in the hierarchy.

Kingdom Protista — most likely a ciliate such as Paramecium. Reasons: (1) a well-defined nucleus means it is a eukaryote, so it is not Monera; (2) it is single-celled, so it is not Fungi, Plantae or Animalia, which are multicellular; (3) unicellular eukaryotes are placed in Protista; (4) many cilia, used for swimming and feeding, are typical of Paramecium (Fig. 12.7).

Diversity keeps an ecosystem balanced and stable because many different organisms perform different and overlapping roles. Producers (plants, algae) make food and oxygen; consumers keep populations in check; decomposers (fungi, bacteria) return nutrients to the soil; pollinators and seed dispersers help plants reproduce. When many species do the same job, the loss of one is made up by others, and in a complex food web a predator can switch to other prey. Diverse forests and mangroves also protect against disasters, such as the 1999 Orissa super cyclone. Losing one species can lead to the decline of others that depend on it.

Several problems would arise: (1) prokaryotes (bacteria, with no true nucleus) and eukaryotes (Amoeba, Paramecium, with a true nucleus) would be in one group, although this is the most basic difference between cells; (2) organisms with very different nutrition — photosynthetic cyanobacteria and Euglena, and heterotrophic Amoeba and yeast — would be mixed; (3) yeast, whose chitin cell wall links it to the fungi, would be separated from its relatives; (4) the group would tell us nothing about the relationships or other features of its members. This is why bacteria were separated into Monera.

Because the five kingdom system classifies organisms by their cells — and a virus has no cell. Every criterion in Fig. 12.5 is unusable on it.

I would give viruses a separate category of their own, outside the five kingdoms. Viruses are important (they cause diseases) and contain genetic material, so they should not be ignored; but they have no cells, no metabolism and cannot reproduce outside a host cell, so they do not fit any kingdom defined by cellular features. A separate category keeps the five kingdoms consistent and still gives viruses a place. This shows that scientific classification is not final: it keeps changing as new tools and evidence appear — from two kingdoms to five, and then to three domains.

Features that keep viruses out: they are acellular — only genetic material in a protein coat, with no cell membrane, cytoplasm or cell organelles — so they are neither prokaryotes nor eukaryotes, neither unicellular nor multicellular. They have no metabolism or nutrition of their own and cannot reproduce outside a host cell, where they remain inactive. Limitation shown: a classification system can sort only what its criteria can measure; things on the boundary between living and non-living do not fit, so classification systems have to be revised as knowledge grows.

They are separated by what they have, not by what they both lack — and the decisive character is the presence of vascular tissue. Lacking flowers and seeds is a shared absence, and an absence is a weak character; it groups plants that may be quite unlike each other.

Genus. A genus has fewer members than a class, but its members share more features. Every lower group lies inside the group above it, so at each step down the number of members decreases and the features shared by the members increase. For example, class Mammalia includes bats, whales, elephants, mice and tigers, which share only a few features such as hair and mammary glands; genus Panthera has only a few big cats (tiger, lion, leopard and others), which also share the ability to roar and a similar skull.

Locomotion and autotrophic nutrition alone are not enough (plants are autotrophic but do not move about; animals move but are heterotrophic). The characters that place it in Protista are: (1) it is unicellular — this rules out Plantae, Animalia and Fungi; and (2) its single cell has a true, membrane-bound nucleus, i.e. it is a eukaryote — this rules out Monera, such as cyanobacteria. Its cell wall should be absent or made of cellulose, and it should move by a flagellum, cilia or pseudopodia. Euglena is an example.

The key is the cell wall: it must be made of chitin. That single character overrides the usual “multicellular” requirement of Fungi — which is exactly the reasoning the chapter uses for yeast: “yeast is a unicellular organism, since its cell wall is made up of chitin, it has been put under fungi.”

Suggested identification key

(i) Q — it has a cell wall but no chlorophyll, and grows on dead organic matter.

(ii) P — it has no true nucleus (a prokaryote).

(iii) R is unicellular and can photosynthesise (Protista); Q is multicellular, has no chlorophyll and absorbs food from dead matter (Fungi). Level of organisation and nutrition separate them.

(iv) Animals, fungi and many protists and bacteria are all heterotrophic, so nutrition cannot place S; its tissues and backbone make it a vertebrate animal.

(v) Cellular organisation — T is acellular (a virus), so no cell-based criterion applies. Classification systems have limits and must be revised as knowledge grows.

(vi) Unrelated organisms sharing a habitat would be grouped together — e.g. if R and S came from the same pond, a protist would be grouped with a vertebrate — hiding real relationships.

(vii) Fungi — it is eukaryotic, multicellular, lacks chlorophyll and absorbs nutrients from outside, as parasitic fungi do; animals take food into the body.

Method: go early in the morning, carry a notebook, a hand lens and a small jar. For each organism record what you can actually see — number of cells is not visible, so record structure and work the kingdom out afterwards using Fig. 12.5.

Sample comparison. A gardener or forest worker usually identifies a plant by its leaf shape, bark, smell, taste, latex, flowering season and the place where it grows, and uses a local name learnt from experience. Scientists use the same visible features and also internal structure, cell structure, reproduction and DNA, and give each species one scientific name used worldwide. The two methods support each other, as in Hortus Malabaricus, compiled with the help of local experts such as Itty Achudan.

Organise it the way a taxonomist does — one record per species, filed in the classification hierarchy, with fields that can be searched and counted.

What one record should hold:

How to arrange the records: group them by family and order first, because that is how field guides are built and it puts similar birds side by side — all four hornbills together. Then add cross-index lists by habitat type, by feeding habit and by season, so the same data can answer different questions. Keep the file in a spreadsheet so it can be sorted and counted.

Safety first: never taste a mushroom, and never collect one for eating on your own judgement. Go with a knowledgeable community resource person and wear gloves. For each mushroom, record where it grows (dead log, living tree, soil), the shape and colour of its cap, gills or pores underneath, any ring on the stalk or cup at the base, its smell and the season, and photograph it whole. Write its local name and what the community says — edible, medicinal or poisonous — and get every identification confirmed by an expert.

Collect stamps (or printed pictures) showing plants and animals, and mount each on a card with its common name, scientific name, country and year. Classify them by your own criteria, for example: by kingdom (most will be Plantae or Animalia); by plant group (Thallophyta to Angiosperm); by animal group (invertebrates; fish, amphibians, reptiles, birds, mammals); endemic Indian species; conservation status; or country and year of issue. For the exhibition, make one panel for each criterion, saying which criterion you used and why.

Sample answer — the Asiatic cheetah in India (declared extinct in the country in 1952). It was the fastest predator of India’s open grasslands and hunted blackbuck and chinkara. It disappeared because of hunting and the loss of grasslands to farming. Scavengers such as vultures and jackals lost the remains of its kills, and grazing animals lost a major predator, so the balance between the grazers and the grassland changed. As the chapter says, when one species disappears, others that depend on it may also decline.

Method: pick three or four contrasting regions, and for each record the animals kept, the breed names, what they are kept for, and the feature that suits them to that place. Talk to a farmer or a veterinary worker if you can.

scientists are likely to learn much more from DNA studies — cheaper genome sequencing, and reading the DNA of microbes that cannot be grown in the laboratory. They may also discover new species in unexplored places such as the deep sea, caves and forest canopies, and learn more from fossils and ancient DNA. This may reveal new relationships, split or join existing groups, add new groups (for example, a proper place for viruses) and change the classification system further — just as microscopes led from two kingdoms to five, and DNA studies led to three domains.