BBIIOOLLOOGGYY - storage.googleapis.com

ILLUSTRATED

ENCYCLOPEDIA

BIO

LOGY

ISBN 978 1 7418 3765 7

9 781901 323511

Bud A small growth on a stem or branchthat will develop into a flower, stem orleaf. In some plants, buds are enclosedwithin protective, modified leaves calledscales until they are ready to grow.

Chlorophyll A green pigment, presentin all green plants, that absorbssunlight and uses the sun’s energy tocarry out photosynthesis.

PPLLAANNTTFFUUNNCCTTIIOONNSS

Aplant’s body has specialized partsfor different jobs. Its leaves makefood using energy from sunlight, a

process called photosynthesis. Most plants have roots that take in water,minerals and other substances from thesoil, as well as a stiff stem that supportsthe plant above the ground. Floweringplants have male and female parts thatmake seeds ( 18). Other plants reproduceeither asexually ( 18) or through thedispersal of spores ( 18).

! The word photosynthesis means“making with light”.

! 65-80% of a plant is made up of water.

! The deepest living plant root ever foundwent 60 m below ground.

! The largest simple leafever found was 3 m longand nearly 2 m wide. It belonged to an arumplant in Malaysia.

! Some species ofbamboo, grow up to 91 cm per day, makingthem the world’s fastest-growing plants.

FF AA CC TT FF II LL EE

LAYERS OF A LEAF

The Venus fly trap is a carnivorous plant that takesnutrients from insects instead of the soil. Like otherplants, it also makes food using photosynthesis.

Close-up photograph of guard cells surrounding astoma on the underside of a leaf.

A simple leaf

A compoundleaf, withseven leafltets.

Chloroplast A small structure within thecell of a plant that contains the pigmentchlorophyll. Photosynthesis is carried outinside the chloroplasts of a plant.

Compound leaf A leaf divided into smallerparts, called leaflets, joined to one stem.

Epidermis The outermost layer of a plant,covering its leaves, stems, roots andpetals. It protects the plant from damageand reduces the amount of water lostthrough evaporation. In the roots, theepidermis absorbs water and nutrients.

Foliage The leaves of a plant.

Frond The leaf of a palm or fern, dividedinto multiple leaflets. Fronds grow fromtightly coiled buds at the base of a plant.As the frond unrolls, its tiny leaflets openup and grow.

Guard cells Two crescent-shaped cellslocated either side of a plant’s

stoma. The cells become largeror smaller to adjust the size ofthe stoma’s opening. Guardcells are activated by light sothat they open the stomata

during the day and close them atnight to reduce water loss.

Leaf A flat surface on a plantwhere photosynthesis andtranspiration take place. Mostleaves are broad so that as much

light as possible can fall on them.

Mesophyll The soft inner layer of a leafbelow the epidermis. The upper layer of the mesophyll, called the palisadelayer, contains chloroplasts forphotosynthesis. The lower layer, calledthe spongy mesophyll layer, is wherecarbon dioxide, water vapour andsugars move around between cells.

Phloem The tissue inside vascular plants ( 15) that carries sugars made by

photosynthesis from the leaves to therest of the plant.

Photosynthesis The process by whichgreen plants use sunlight as an energysource to combine carbon dioxide from the air and water from the soil to makesugars plants use as food. Plants use thissugar to power their life activities.Photosynthesis also produces oxygen,which seeps out into the air.

Rhizoid A root-like structure in plants suchas mosses. Rhizoids may anchor a plant tothe ground, absorb water, or both. Unliketrue roots, rhizoids do not contain vasculartissue (xylem and phloem).

Rhizome A horizontal stem that growsbeneath the ground. Shoots and rootsgrow from the rhizome.

Root The part of a vascular plant ( 15) thatnormally grows below ground. Rootsanchor a plant and take in water anddissolved minerals from the soil. The firstroot to grow is the primary root, whichthen sprouts sideways lateral roots.

Root hairs Fine growths at the tip of eachroot. They increase the surface area ofroots so they can take up more nutrients.

Simple leaf A leaf not divided into leaflets.

Shoot A new growth on part of a plant.

Stem The long, stiff part of a vascular plant( 15) that supports its leaves, flowers, fruitsor cones. It contains tissues that carrywater and nutrients around the plant.

Stoma (plural: stomata) A tiny hole on theunderside of a leaf, through which carbondioxide enters and oxygen seeps out.

Tendril A modified leaf used by climbingplants to wrap around objects for support.

Transpiration The controlled release ofwater as vapour through a plant’s stoma.Loss of water in the leaves creates suction,which draws up water from the roots. This water carries nutrients absorbed bythe roots around the rest of the plant.

Vascular tissue Xylem and phloem tissuesthat carry water, and minerals and sugarsdissolved in it, around vascular plants ( 15).

Veins Xylem and phloem cells in a leaf thatsupport its structure and transport waterand nutrients to all of its cells.

Xylem The tissue in vascular plants ( 15)

that carries water and dissolved mineralsfrom a plant’s roots to the rest of theplant. This liquid is called sap.

Tropism The growth or slight movementof a plant in response to a change in itsenvironment. For example, phototropismis the movement of a plant towards oraway from light and geotropism is thegrowth of a plant in response to gravity.

Tuber A thick, underground stem or rootthat stores food for the next growingseason. Potatoes are a type of stem tuber.

The edible part of a carrot

is its primary root.

Chloroplast Vein

Stoma

Sunlight

Carbondioxide

Stem

Water andnutrients

Roots

Leaf

Oxygen

Watervapour

Flower

1716

Epidermis

Pallisadelayer

Spongy mesophyll layer

! Covers 12 major subject areas of biology

! More than 250 keywords alphabetically listedand clearly explained

! Fact panels with extra information

! About 100 detailed illustrations

! Comprehensive index

BBIIOOLLOOGGYYII LL LL UU SS TT RR AA TT EE DD EE NN CC YY CC LL OO PP EE DD II AA

BBIIOOLLOOGGYYFirst published in 2012 by Orpheus Books Ltd., 6 Church Green, Witney, Oxfordshire, OX28 4AW, England

www.orpheusbooks.com

Copyright ©2012 Orpheus Books Ltd.

Created and produced by Nicholas Harris, Sarah Hartley, Katie Sexton, Ruth Symons and Erica Williams, Orpheus Books Ltd.

Text Ruth Symons

Illustrated by Graham Austin, Martin Camm, Stuart Carter, Fiammetta Dogi,Malcolm Ellis, Elisabetta Ferrero, Sauro Giampaia, Ray Grinaway, Inklink,

Ian Jackson, Mike Lowe, David More, Nicki Palin, Sebastian Quigley, Peter David Scott, Martin Woodward, Colin Woolf, David Wright

Consultant Richard Walker, writer and consultant

All rights reserved. No part of this book may be reproduced, stored in aretrieval system, or transmitted in any form or by any means, electronic,

mechanical, photocopying, recording or otherwise, without the priorwritten permission of the copyright owner.

ISBN 978 1 7418 3765 7

Printed and bound in Singapore

Photographs on pages 7, 11 and 12: Wikimedia Commons/Public DomainPhotograph on page 10: Copyright ©2011 Nanka (Kucherenko Olena)

Used under licence from Shutterstock.comPhotograph on page 17: Dr Jeremy Burgess, Science Photo Library

Photograph on page 27: Copyright ©2011 Eric IsseléeUsed under licence from Shutterstock.com

II LL LL UU SS TT RR AA TT EE DD EE NN CC YY CC LL OO PP EE DD II AA

The second largest kingdom of livingthings is the plant kindom. The keyfeature of a plant is that it obtains

energy from sunlight by photosynthesis( 16). Plants do not have sensory organsand, although they can grow towardslight or water, they cannot move freelyaround their environment. Fungi, oncethought to be plants, are now classified asa separate kingdom. Fungi include:mushrooms, yeasts ( 13) and moulds.They decompose dead or dying plants andanimals and take their energy from thenutrients they release.

! Flowering plants are the prevailinggroup of land plants around the world,except for colder regions, whereconiferous plants dominate.

! The first land plants evolved around500 million years ago from green algae.

! The world’s oldest organism is the slow-growing Jurupa oak, found in California andbelieved to be 13,000 years old.

! A scientist whostudies plants iscalled a botanist.

! The pitcher plant(right), is acarnivorous plantthat lures insectsusing the scent of itsnectar. Insects fall intobottle-shaped pitchersfilled with rainwater andthe plant’s digestive juices,and drown.

Clubmoss A low-growing, green plantwith scale-like leaves. Club mossesreproduce using spores ( 18).

Conifer A cone-bearing plant, also knownas a gymnosperm. Conifers reproduceusing seeds formed in scaly cones ( 20).All conifers are bushes or trees.Most have long, narrow leavesthat do not fall in autumn.

Cycad A palm-like woodyplant that producesseeds via cones ( 20).Cycads grow in tropicalregions and werecommon during the timeof the dinosaurs.

Rafflesia, a parasite, is the world’slargest flower.

Inside a fungus’s fruiting body, atoadstool (1), fungal spores are

formed (2) and released (3). In suitableconditions a spore grows a hypha (4).

Moss

Magnolia Dicot A flowering plant with twocotyledons ( 16) and petals in multiplesof four or five. Most flowers, bushes andtrees are dicots.

Epiphyte A plant that grows on other plantsfor support, typically to reach more light.Epiphytes collect rainwater and leaf litter,which provide them with nutrients.Epiphytes include bromeliads and orchids.

Fern A flowerless green plant with a long,stiff stem, and branching leaflets ( 16)

known as “fronds”. Ferns grow in dampplaces and can live in low light levels. Sometropical ferns grow as epiphytes.

Flowering plant A plant, also known as anangiosperm, that flowers and producesfruits containing seeds ( 18).

Ginkgo An ancient, non-flowering plantwith fan-shaped leaves. The only survivingspecies is native to China.

Gnetophyte A woody, seed-bearing plant.Gnetophytes include: Ephedra, a shrub fromthe US; Gnetum, a tropical forest vine andWelwitschia, a cactus-like plant.

Hemiparasite A plant that obtains energythrough both photosynthesis and byparasitic means. Mistletoe is a hemiparasite.

Cactus A succulent that has adapted toopen its stomata (pores) only in the cool ofthe night. Most cacti are covered in spinesto stop animals eating them. They are oneof the few plants that flourish in deserts.

Carnivorous plant A plant that obtainsnutrients by digesting animals. Carnivorousplants live in places where soils are lackingessential minerals. They trap animals usingpitfall traps, sticky surfaces and snap traps.

Herbaceous plant A plant whose leaves andstem die down to soil level at the end ofthe growing season. Herbaceous plantsinclude irises, peonies and carrots.

Horsetail A spore-bearing vascular plantwith a rigid, hollow stem. Horsetails arebrush-like in appearance and are oftenfound near rivers, lakes or swamps.

Vascular plant A plant withtiny, tube-like vessels thatcarry water, nutrients and sugararound its body. Vascular plants all haveroots, stems and leaves.

Vine A plant with a long, thin stem thatclimbs up other plants, rocks or otherstructures for support.

Annual plant A plant that germinates ( 18),flowers and dies within one growingseason (usually a year). Annual plantsinclude corn, lettuce, beans and marigolds.

Aquatic plant A plant that lives in water.

Biennial plant A flowering plant that takestwo years to complete its life cycle. In thefirst year, it stores energy obtained throughphotosynthesis. In the following year, ituses this energy to flower and make seeds.Biennials include hollyhocks and pansies.

Bryophyte A non-vascular plant, such as amoss, that absorbs water and mineralsthrough its leaves and reproduces usingspores ( 18).

FF AA CC TT FF II LL EEAssorted cactigrowing in an

American desert

Moss A bryophyte withleafy stems. Many species

spread across the ground, forming a mat.

Mould A furry growth of fungi on damp ordecaying organisms.

Mushroom An umbrella-shaped fruitingbody, grown when a fungus reproduces.The mushroom’s top, or cap, releasesmillions of tiny fungal spores ( 18) thatblow away in the wind. Poisonousmushrooms are often called toadstools.

Mycelium The network of threads in afungus. Mycelia grow into the bodies ofdead or dying organisms, causing them todecompose. They then absorb the released nutrients.

Non-vascular plant A plant, such as abryophyte, that has no tube-like vessels forcarrying water and nutrients. Non-vascularplants normally live in damp places.

Parasitic plant A plant that takes water and nutrients from another plant, knownas the host. Parasitic plants may attachthemselves either to the outside or insideof the host.

Perennial plant A plant that lives formore than two years. Many smallerperennials are herbaceous. All treesand most shrubs are perennial.

Shrub A low-lying plant withwoody stems branching out froma base just above the ground.

Succulent A plant that storeswater in its stem, leaves or roots.Most succulents have smallleaves and waxy surfaces in orderto prevent water loss.

Crocos, a monocot

Hornwort A flat bryophyte that releasesspores ( 18) from horn-shaped capsules.

Hyphae A long, thin thread forming themycelium of a fungus.

Lichen Algae ( 12) and fungi living together.The algae makes food via photosynthesis.The fungus gathers water and forms aprotective layer over the algae. Because ofthis relationship, lichens are very hardy.

Liverwort A small, mat-like bryophyte.Liverworts have either simple leaves or flatgreen bodies that look like leaves.

Monocot A flowering plant with just onecotyledon ( 18) and petals in multiples ofthree. Monocots include lilies and tulips.

PPLLAANNTTSS &&FFUUNNGGII

Buttercup, a dicot

Mushroom

1

2

3

4

1514

The frondsof a fern

Liverwort

AABBOOUUTT TTHHIISS BBOOOOKK

Each double page contains a brief introduction,explaining the general subject, followed by key

words arranged in alphabetical order. To look up aspecific word, turn to the index at the back of thisbook: this will tell you which page to go to. If you wantto learn more about a subject, take a look at the factfile, orfollow the arrows to read related entries.

INTRODUCTIONThis explains thegeneral subjectand provides somebasic knowledge.

KEY WORDS AND ENTRIESKey words are arranged alphabeticallyacross each double page. Each entryprovides a short explanation of whatthe key word means.

PAGE NUMBERPage numbersare easy to findat the side ofthe page.

FACTFILEThe factfile provides extrainformation on the subject.Facts are presented in easyto read bullet points.

LLIIFFEE 66

CCLLAASSSSIIFFIICCAATTIIOONN 88

EEVVOOLLUUTTIIOONN 1100

MMIICCRROO--OORRGGAANNIISSMMSS 1122PPLLAANNTTSS && FFUUNNGGII 1144

PPLLAANNTT FFUUNNCCTTIIOONNSS 1166

FFLLOOWWEERRSS && SSEEEEDDSS 1188

TTRREEEESS 2200

AANNIIMMAALL BBEEHHAAVVIIOOUURR 2222

CCOONNTTEENNTTSS

AANNIIMMAALL MMOOVVEEMMEENNTT 2244

AATTTTAACCKK && DDEEFFEENNCCEE 2266

MMIIGGRRAATTIIOONN 2288

IINNDDEEXX 3300

BOLD WORDSThese highlightuseful words thatdo not have theirown entry.

ARROWS These arrows show you where to look up otherwords mentioned in the entry. For example, ( 26) tells you to go forward to page 26 and ( 6) tells you to turn back to page 6.

! The first life-forms on Earth appearedabout 3700 million years ago, probably inthe sea. They were formed when certainsimple chemicals joined to each other toform more complex ones, although it is notknown how this first occurred.

! People once thought living things couldappear from nothing. For instance, it wasbelieved that maggots developed fromrotting meat. In 1668, Italian Francesco Redishowed this was not the case by provingmaggots developed from eggs laid by flies.To prove his theory, he placed meat in twojars—one open, one sealed. Days later,there were maggots only in the open jar,the one that flies had been able to enter.

LLIIFFEE

Living things are called organisms. Organisms can be classified, or putinto groups, according to their

similarities, relationships and ancestry.Most scientists think that organisms aredivided into three domains: archaea,bacteria and eukaryota. Each of these isthen divided into further groups, or ranks,of decreasing size: kingdom, phylum,class, order, family, genus and species.

Earth’s surface millions of years after its formation.Its warm, shallow seas were a soup of chemicals

from which living things probably formed.

Bacteria Protists Fungi Plants Animals

Animal kingdom The largest eukaryotickingdom. Animals can sense theirsurroundings, move independently andtake in energy by eating other living things.

Hybrid An organism that is the offspring ofparents from two different species. Hybridsare usually unable to reproduce.

Kingdom The taxonomic rank abovephylum and below domain. All organismsare split into six kingdoms: archaea,bacteria, protists, fungi, plants and animals.

Linnaeus, Carolus (1707-1778) Swedishscientist who invented the system of two-part scientific names and introduced ranks,including kingdom, class and order.

Order The taxonomic rank above family and below class.

Organism Any living thing. All organismsconsist of a cell or cells. They convertchemicals to provide materials for growthand the release of energy to power lifeprocesses. All organisms can reproduce andrespond to changes in their surroundings.

Phylum The taxonomic rank above classand below kingdom. Instead of phyla, theplant kingdom is split into divisions.

Plant kingdom One of the eukaryotickingdoms. Plants obtain energy from lightvia photosynthesis ( 16). They also absorbwater and minerals from the ground. Plantscannot move freely around their habitat.

Protist kingdom One of the eukaryotickingdoms. A protist is made up of a singlecell containing a nucleus ( 11).

Rank A level, such as species, genus orclass, within the taxonomic system.

FF AA CC TT FF II LL EE

TAXONOMICRANK

NAME (scientificand common)

ORGANISMS INCLUDED

Species

Genus

Family

Order

Class

Phylum

Kingdom

Panthera tigrisTiger

PantheraBig cats

6 subspecies: Bengal, Indochinese,Malayan, Sumatran, Siberian and

South China tiger

Jaguars, tigers, lionsand leopards

FelidaeCats

Big cats, cougars, cheetahs, servals, lynxes, caracals,

ocelots and domestic cats

CarnivoraCarnivores

Cats, dogs, civets, hyenas, bears,mongooses, weasels, raccoons, seals,

sea lions, walruses and others

MammaliaMammals

ChordataVertebrates

Mammals, birds, reptiles, amphibiansand fish

AnimaliaAnimal kingdom

Vertebrates, arthropods, molluscs,sponges, worms and others

Taxonomy The classification of all livingthings into ranks of varying sizes,including species, genus, family, class,order, kingdom and domain.

TAXONOMIC CHART (left) showing how, forexample, tigers are classified.

Archaea One of the three domains.Archaea are a group of single-celledorganisms with no cell nucleus ( 12). Theydiffer from bacteria ( 12) in their chemicalmake-up. Within this domain there is justone kingdom, also called archaea.

Carbon A common chemical that forms a part of all living cells.

Class The taxonomic rank above order and below phylum.

Domain The highest rank into which life isdivided. The three domains are: bacteria ( 12), archaea and eukaryotes. Bacteria andarchaea, distinguished by their chemicalmake-up, are each split into one kingdom.Eukaryotes are divided into four kingdoms.

Eukaryotes One of the three domains.Eukaryotic organisms have one or morecells and, unlike archaea or bacteria, theircells have a nucleus and organelles ( 12).Eukaryotes are divided into four kingdoms:animals, plants, fungi and protists.

Family The taxonomic rank above genusand below order.

Fungi kingdom One of the eukaryotickingdoms. It includes mushrooms, yeasts,moulds and mildews. Most fungi feed ondead and decaying organisms, andreproduce using spores ( 19).

Genus The taxonomic rank above speciesand below family.

Every cell in every organism contains DNA ( 10).This is a model of its structure.

Reproduction The production of offspring.All living things can reproduce.

Respiration A process that takes place inall living things, by which chemicals arebroken down to release energy. Mostorganisms need oxygen for respiration.

Scientific name A two-word name for aspecies. The first word is its genus (eg.Panthera). She second is its specific name(eg. tigris), which identifies it as onespecies (Panthera tigris) within that genus.

Species A group of organisms that areusually similar in appearance, and that areable to breed together and produce youngthat can also breed successfully.

Subspecies A subgroup of a species, oftengeographically isolated from othersubspecies. Different subspecies couldbreed successfully if brought into contact.

THE SIX KINGDOMS

6 7

Carnivores, ungulates, primates, insectivores,rodents, marsupials and others

Domain EukaryotaEukaryotes

Protists, fungi, plants and animals

Archaea

Bryophytes

CCLLAASSSSIIFFIICCAATTIIOONN

Classification is a way of grouping all organismstogether to show how they are related to oneanother. This chart shows how the three domains ( 6)

of life are split into kingdoms and classified by biologists.

PROTISTS

FUNGI

PLANTS

Angiosperms

KEY:

Kingdom

Phylum/Division

Class

Conifers

Cycads

Ginkgos

Club mosses Gnetophytes

DicotsMonocotsMossesHornwortsLiverworts

Sac fungi Imperfect fungi

Diatoms Dinoflagellates Red algae Brown algae Green algae

Golden algaeCnidosporidiansApicomplexansCiliates

HeliozoansForaminiferansAmoebaeFlagellatesFungal protists

Chordates

Sponges

Cnidarians

Rotifers

Water bears

Arthropods

Lampshells

Moss animals

around 13minor phyla

AN

IMA

LS

Mammals

Birds

Amphibians

Reptiles

Jawless fish

Bony fish

Cartilaginous fish

Sea urchins

Starfish

Feather stars

Brittle stars

Sea cucumbers Octopuses andsquid

Chitons

Mussels andclams

Tusk shells

Deep-sea limpets

Arachnids

Horseshoe crabs

Sea spiders

Centipedes

Millipedes

Insects

Velvet worms

Spiny-headedworms

Segmentedworms

Horsehairworms

Roundworms

Flatworms

Red octopus

Hammerhead shark

Hermit crab

9

Amoeba

Fern

Fly agarictoadstool

Crustaceans

Molluscs

Echinoderms

Snails and slugs

RhinocerosBeetle

Comb jellies

Gazelle

Ferns &horsetails

Domain

ARCHAEA

BACTERIA

EUKARYOTES

Protists

Fungi

Plants

Animals

8

Club fungiMoulds

Euglenoid

Genetics The branch of science that dealswith heredity—how features are passedon, or inherited, from parent to offspringvia the genes.

Homologous structure A structure shared by species that may look differentbut evolved from a common ancestor. For example, bat wings and human armslook different but are built from the sameset of bones.

Mendel, Gregor (1822-1884) Austrian priestwho observed that most features of aplant are determined by the features of itsparents. He published his findings in 1866.

Mutation A change to the structure of agene. This may occur spontaneously or betriggered by outside factors such asradiation or chemicals. Many mutations areharmful and cause damage if passed on tooffspring. Some are beneficial and result inoffspring that are more likely to survive,breed and pass on the mutated gene.

Natural selection The process wherebyorganisms best suited to their environmentare more likely to survive and reproduce. If their offspring inherit the same features,they, too, have a better chance of survival.Individuals less well adapted may notsurvive to reproduce. Natural selection isthe driving force of evolution.

Sexual selection A type of naturalselection that occurs because one sexprefers certain features in individuals ofthe opposite sex. For example, femalepeahens choose their mate on the basis ofhis tail feathers. A male peacock withlarge tail feathers has a greater chance ofmating and passing on his genes.

Speciation The formation of a newspecies as a result of divergent evolution. If one group within a species becomesisolated, does not breed with othergroups, and so evolves separately, itsmembers will gradually become more and more different and eventually form a new species.

! For thousands of years, humans havebred domestic animals or crops with“desirable” features to emphasise thosefeatures in the next generation. This iscalled “artificial selection”.

! Natural selection does not always makeorganisms more complex. Sometimes itmakes creatures simpler. For example, theancestors of fleas, like most insects, hadwings. In the course of evolution, fleas havelost their wings as an adaptation to movingeasily through fur or feathers.

! Charles Darwin(right) spent fiveyears on board theHMS Beagle,makingobservationsabout the plantsand animalsencountered on theship’s journey. During theexpedition, he sent over 5000 fossil, plantand animal specimens back to England.

The embryos of a fish, turtle, cow and human alllook similar: they evolved from the same ancestor.

Scientists can trace the evolution of a species byexamining fossils. Here are some of the ancientrelatives of modern elephants.

Hawaiian finches—an example ofadaptive radiation

Nectar andinsect eater

The light colouringof peppered mothscamouflages ( 12)them against pale-coloured lichens ontrees. This preventspredatory birdsfrom spotting them.

During the Industrial Revolution,many trees became blackened bysoot. Natural selection resulted indarker, better-camouflaged mothsbecoming much more abundant.

Fruit eater

A fossil ammonite

Seed eater

Insect eater

Modern African elephant

Moeritherium c. 37 million years ago

Palaeomastodonc. 36 mya

Gomphotheriumc. 14 mya

Steppe mammoth600,000 years ago

Variations Differences between individualsof the same species. They are the result ofan individual’s unique combination ofgenes, including inherited mutations.

Vestigial organ A body part that hasbecome smaller or seemingly functionlessin the course of evolution. For example,the appendix in some hervibores is largeand involved in digesting plant material; in humans it is small and vestigial andplays no obvious part in digestion.

Wallace, Alfred Russel (1823-1913) Englishscientist who, independently of Darwin,proposed a theory of evolution by naturalselection in the 19th century.

EEVVOOLLUUTTIIOONN

Evolution is the process by whichliving things gradually change; thismay make them better suited to their

environment. Variations within speciesmean that some individuals are bettersuited to their lifestyle than others. Theseindividuals are more likely to survive andreproduce, passing on the features thathelped them survive. However, conditionschange naturally with time: some foodsmay become scarcer or the climate maychange. Evolution may allow someorganisms to survive in the new conditions.

FF AA CC TT FF II LL EE

As a result of genetic mutation, albinos such as thisrat (right) have no pigment in their skin, hair or eyes.

Adaptation The process whereby livingthings tend, over several generations, tobecome better suited to their environment.Organisms are adapted to climate, availablefoods and the avoidance of predators.

Adaptive radiation The evolution of manydifferent species, such as Hawaiian finches,from a single species. It often happenswhen a species moves to a new area andindividuals take to different ways of life.

Extinction The process whereby everymember of a species or subspecies dies out.

Fossil The remains of once-living thingspreserved in rock. If a dead organism isquickly buried by sand or mud, its remainsmay, over millions of years, turn into rock.Fossils show long-extinct organisms thatprovide evidence for evolution.

Genes A set of instructions that tell anorganism how to grow and maintain itself.Genes are contained within DNA. Becausethey control the way cells are built, geneshelp determine an organism’s features.

Parallel evolution The development ofsimilar features in related, but different,species. For example, Old World and NewWorld porcupines, which both share anancestor, evolved spines independently.

A male peacock’s tail feathers show sexual selection.

1110

Analogous structure A structure with thesame function that is found in unrelatedspecies. For example, the wings of birds,bats and insects are analogous, becausethey evolved independently.

Convergent evolution The evolution ofsimilar features in living things that areunrelated but whose ways of life are alike.For example, whales and sharks both havestreamlined bodies and fins that enablethem to move through water easily.

Darwin, Charles (1809-1882) Britishscientist who established the theory ofevolution by natural selection. In 1859, he published his theory in his book On the Origin of Species.

Divergent evolution The process of two or more closely related species becomingmore dissimilar, often when they live indifferent habitats. For example, the desert-living kit fox is paler than thewoodland-living red fox, an adaptationthat helps it blend in with its surroundings.

DNA (Deoxyribonucleic acid) A chemicalinside the cells ( 12) of all living things. DNAcan copy itself and carries the instructions(genes) needed to build and run a cell.

Embryology The study of animals’ earlydevelopment. Similarities between theembryos of mammals, birds, reptiles andfish indicate that they evolved from acommon ancestor.

MMIICCRROO--OORRGGAANNIISSMMSS

Micro-organisms are tiny livingthings that are far too small forus to see without a powerful

microscope. They are all around us: in theair, in the water, even inside our bodies.Micro-organisms include bacteria,viruses, protists and some fungi. Othermicroscopic life-forms include the youngof some plants or animals.

Bacillus A rod-shaped bacterium.

Cell A tiny “building block” which makesup the tissues in all living things. It istypically a bag of jelly containing a nucleusand other working parts, called organelles.

Ciliate A large protozoan covered withhair-like cilia. These beat back and forth tomake the organism move.

Coccus A spherical, or ball-shaped,bacterium.

Cyanobacterium A bacterium, also knownas blue-green algae, that produces its ownfood using photosynthesis ( 16).

Aspergillus A microscopic fungus ( 14) thatgrows on decaying matter and soil. Some species can cause disease in humans.

Bacterium (plural: bacteria) A simplesingle-celled organism. Bacteria are foundnearly everywhere, including in air, water,ice, rocks and inside other organisms. Some bacteria cause disease in humans.

Diatoms Single-celled algae that live inponds, rivers and oceans. Diatoms areprotected by a hard case.

Didinium A freshwater ciliate that feedson protists much larger than itself.

Dinoflagellate A marine alga with astrong, rigid cell wall and pointed hornsthat help it to float upright.

Euglena A protist that makes its food by photosynthesis ( 16) and moves byflicking its tiny, whip-like flagellum.

Flagella Tail-like projections that enablesome micro-organisms to swim. Flagellaare used in a whipping motion to propelorganisms through the water.

Foraminiferan A small protozoan, with arigid, case-like cell wall, like a beautifully-shaped shell.

Heliozoan A spherical, freshwaterprotozoan, surrounded by long, stiffprojections that are used to catch prey.

Multicellular Consisting of more than one cell.

Nucleus A large structure in some cells,that contains a cell’s genes ( 10) andtherefore controls all cell activities.

Organelle A tiny structure inside somecells. Each type of organelle has its ownspecific function. The word organellemeans “little organ”.

Prokaryote A single-celled organism, such as a bacterium, that lacks a nucleusand organelles.

Protist An organism made up of a single cell containing a nucleus. Protists live mainly in water and dampplaces. Some (algae) make energy byphotosynthesis ( 16) but others(protozoans) take in food.

Protozoan (plural: protozoa) A protistthat obtains energy by eating food. Some protozoa sift food particles frompassing water. Others actively hunt prey.

Spirillum A corkscrew-shaped bacterium.

Virus A microscopic package of chemicals that causes disease and can

only reproduce by invading the cells of a living organism. Some human

diseases, such as colds and flu, are caused by viruses.

Vorticella A transparent protozoan with abell-shaped body attached to a stalk. Hair-like cilia waft food into its mouth.

Yeast A microscopic, single-celled fungus ( 14) found in soil and on plants.Yeasts contain chemicals that change sugar into alcohol and carbon dioxide gas.

Salmonella bacteria (red) invading human cells. The bacteria move with the help of tail-like flagella.

Diatom

Billions of protists live in the sea.

An amoeba flowstowards a smallerbacterium andswallows it whole.

This E. coli bacterium (above) is approximately0.0015 mm long. It is much larger than a virus(above, left) which is only about 0.0001 mm long.

FF AA CC TT FF II LL EE

Dinoflagellate

! Bacteria are the commonest livingthings.

! A quarter of a million bacteria can fit onto a single pinhead.

! Yeast is used in the manufacture ofsome food and drinks. In bread-making, itproduces the gases that make dough rise.

! The earliest living things on Earth wereprokaryotes.

! Viruses can exist in a dormant state foryears when not in contact with the livingcells of a host. But as soon as it infects ahost, a virus becomes active and invadescells in order to reproduce.

Alga (plural: algae) A plant-like protistfound in water or moist ground. Algaemake food by photosynthesis ( 16). Theyrange from single-celled organisms tolarge, multicellular forms, such as seaweed.

Amoeba A protozoan with no definiteshape. Amoebae live in water and move byflowing like a bag full of jelly. They feed onother micro-organisms, such as bacteria,and reproduce by splitting in two.

Apicomplexa A group of parasiticprotozoans, including the species that cause malaria in humans. Most acicomplexans invade and liveinside the cells of other organisms.

A computerized model of an adenovirus (above),one of the viruses that causes the common cold. It has an outer protein shell made of triangularsections. Inside it is a length of DNA. 12 13

The second largest kingdom of livingthings is the plant kindom. The keyfeature of a plant is that it obtains

energy from sunlight by photosynthesis ( 16). Plants do not have sensory organsand, although they can grow towardslight or water, they cannot move freelyaround their environment. Fungi, oncethought to be plants, are now classified asa separate kingdom. Fungi include:mushrooms, yeasts ( 13) and moulds. They decompose dead or dying plants andanimals and take their energy from thenutrients they release.

! Flowering plants are the prevailinggroup of land plants around the world,except for colder regions, whereconiferous plants dominate.

! The first land plants evolved around 500 million years ago from green algae.

! The world’s oldest organism is the slow-growing Jurupa oak, found in California andbelieved to be 13,000 years old.

! A scientist whostudies plants iscalled a botanist.

! The pitcher plant(right), is acarnivorous plantthat lures insectsusing the scent of itsnectar. Insects fall intobottle-shaped pitchersfilled with rainwater andthe plant’s digestive juices,and drown.

Clubmoss A low-growing, green plantwith scale-like leaves. Club mossesreproduce using spores ( 18).

Conifer A cone-bearing plant, also knownas a gymnosperm. Conifers reproduceusing seeds formed in scaly cones ( 20).All conifers are bushes or trees. Most have long, narrow leavesthat do not fall in autumn.

Cycad A palm-like woodyplant that producesseeds via cones ( 20).Cycads grow in tropicalregions and werecommon during the timeof the dinosaurs.

Rafflesia, a parasite, is the world’slargest flower.

Inside a fungus’s fruiting body, atoadstool (1), fungal spores are

formed (2) and released (3). In suitableconditions a spore grows a hypha (4).

Moss

Magnolia Dicot A flowering plant with two cotyledons ( 16) and petals in multiples of four or five. Most flowers, bushes andtrees are dicots.

Epiphyte A plant that grows on other plantsfor support, typically to reach more light.Epiphytes collect rainwater and leaf litter,which provide them with nutrients.Epiphytes include bromeliads and orchids.

Fern A flowerless green plant with a long,stiff stem, and branching leaflets ( 16)

known as “fronds”. Ferns grow in dampplaces and can live in low light levels. Sometropical ferns grow as epiphytes.

Flowering plant A plant, also known as anangiosperm, that flowers and producesfruits containing seeds ( 18).

Ginkgo An ancient, non-flowering plantwith fan-shaped leaves. The only survivingspecies is native to China.

Gnetophyte A woody, seed-bearing plant.Gnetophytes include: Ephedra, a shrub fromthe US; Gnetum, a tropical forest vine andWelwitschia, a cactus-like plant.

Hemiparasite A plant that obtains energythrough both photosynthesis and byparasitic means. Mistletoe is a hemiparasite.

Cactus A succulent that has adapted toopen its stomata (pores) only in the cool ofthe night. Most cacti are covered in spinesto stop animals eating them. They are oneof the few plants that flourish in deserts.

Carnivorous plant A plant that obtainsnutrients by digesting animals. Carnivorousplants live in places where soils are lackingessential minerals. They trap animals usingpitfall traps, sticky surfaces and snap traps.

Herbaceous plant A plant whose leaves andstem die down to soil level at the end ofthe growing season. Herbaceous plantsinclude irises, peonies and carrots.

Horsetail A spore-bearing vascular plantwith a rigid, hollow stem. Horsetails arebrush-like in appearance and are oftenfound near rivers, lakes or swamps.

Vascular plant A plant withtiny, tube-like vessels thatcarry water, nutrients and sugararound its body. Vascular plants all haveroots, stems and leaves.

Vine A plant with a long, thin stem thatclimbs up other plants, rocks or otherstructures for support.

Annual plant A plant that germinates ( 18),flowers and dies within one growingseason (usually a year). Annual plantsinclude corn, lettuce, beans and marigolds.

Aquatic plant A plant that lives in water.

Biennial plant A flowering plant that takestwo years to complete its life cycle. In thefirst year, it stores energy obtained throughphotosynthesis. In the following year, ituses this energy to flower and make seeds.Biennials include hollyhocks and pansies.

Bryophyte A non-vascular plant, such as amoss, that absorbs water and mineralsthrough its leaves and reproduces usingspores ( 18).

FF AA CC TT FF II LL EEAssorted cactigrowing in an

American desert

Moss A bryophyte withleafy stems. Many species

spread across the ground, forming a mat.

Mould A furry growth of fungi on damp ordecaying organisms.

Mushroom An umbrella-shaped fruitingbody, grown when a fungus reproduces.The mushroom’s top, or cap, releasesmillions of tiny fungal spores ( 18) thatblow away in the wind. Poisonousmushrooms are often called toadstools.

Mycelium The network of threads in afungus. Mycelia grow into the bodies ofdead or dying organisms, causing them todecompose. They then absorb the released nutrients.

Non-vascular plant A plant, such as abryophyte, that has no tube-like vessels forcarrying water and nutrients. Non-vascularplants normally live in damp places.

Parasitic plant A plant that takes water and nutrients from another plant, knownas the host. Parasitic plants may attachthemselves either to the outside or insideof the host.

Perennial plant A plant that lives formore than two years. Many smallerperennials are herbaceous. All treesand most shrubs are perennial.

Shrub A low-lying plant withwoody stems branching out froma base just above the ground.

Succulent A plant that storeswater in its stem, leaves or roots.Most succulents have smallleaves and waxy surfaces in orderto prevent water loss.

Crocos, a monocot

Hornwort A flat bryophyte that releasesspores ( 18) from horn-shaped capsules.

Hyphae A long, thin thread forming themycelium of a fungus.

Lichen Algae ( 12) and fungi living together.The algae makes food via photosynthesis.The fungus gathers water and forms aprotective layer over the algae. Because ofthis relationship, lichens are very hardy.

Liverwort A small, mat-like bryophyte.Liverworts have either simple leaves or flatgreen bodies that look like leaves.

Monocot A flowering plant with just onecotyledon ( 18) and petals in multiples ofthree. Monocots include lilies and tulips.

PPLLAANNTTSS &&FFUUNNGGII

Buttercup, a dicot

Mushroom

1

2

3

4

1514

The frondsof a fern

Liverwort

Bud A small growth on a stem or branchthat will develop into a flower, stem orleaf. In some plants, buds are enclosedwithin protective, modified leaves calledscales until they are ready to grow.

Chlorophyll A green pigment, present in all green plants, that absorbs sunlight and uses the sun’s energy to carry out photosynthesis.

PPLLAANNTTFFUUNNCCTTIIOONNSS

Aplant’s body has specialized partsfor different jobs. Its leaves makefood using energy from sunlight, a

process called photosynthesis. Most plants have roots that take in water,minerals and other substances from thesoil, as well as a stiff stem that supportsthe plant above the ground. Floweringplants have male and female parts thatmake seeds ( 18). Other plants reproduceeither asexually ( 18) or through thedispersal of spores ( 18).

! The word photosynthesis means“making with light”.

! 65-80% of a plant is made up of water.

! The deepest living plant root ever foundwent 60 m below ground.

! The largest simple leafever found was 3 m longand nearly 2 m wide. It belonged to an arumplant in Malaysia.

! Some species ofbamboo, grow up to 91 cm per day, makingthem the world’s fastest-growing plants.

FF AA CC TT FF II LL EE

LAYERS OF A LEAF

The Venus fly trap is a carnivorous plant that takesnutrients from insects instead of the soil. Like otherplants, it also makes food using photosynthesis.

Close-up photograph of guard cells surrounding astoma on the underside of a leaf.

A simple leaf

A compoundleaf, withseven leafltets.

Chloroplast A small structure within thecell of a plant that contains the pigmentchlorophyll. Photosynthesis is carried outinside the chloroplasts of a plant.

Compound leaf A leaf divided into smallerparts, called leaflets, joined to one stem.

Epidermis The outermost layer of a plant,covering its leaves, stems, roots andpetals. It protects the plant from damageand reduces the amount of water lostthrough evaporation. In the roots, theepidermis absorbs water and nutrients.

Foliage The leaves of a plant.

Frond The leaf of a palm or fern, dividedinto multiple leaflets. Fronds grow fromtightly coiled buds at the base of a plant.As the frond unrolls, its tiny leaflets openup and grow.

Guard cells Two crescent-shaped cellslocated either side of a plant’s

stoma. The cells become largeror smaller to adjust the size ofthe stoma’s opening. Guardcells are activated by light sothat they open the stomata

during the day and close them atnight to reduce water loss.

Leaf A flat surface on a plantwhere photosynthesis andtranspiration take place. Mostleaves are broad so that as much

light as possible can fall on them.

Mesophyll The soft inner layer of a leafbelow the epidermis. The upper layer of the mesophyll, called the palisadelayer, contains chloroplasts forphotosynthesis. The lower layer, calledthe spongy mesophyll layer, is wherecarbon dioxide, water vapour andsugars move around between cells.

Phloem The tissue inside vascular plants ( 15) that carries sugars made by

photosynthesis from the leaves to therest of the plant.

Photosynthesis The process by whichgreen plants use sunlight as an energysource to combine carbon dioxide from the air and water from the soil to makesugars plants use as food. Plants use thissugar to power their life activities.Photosynthesis also produces oxygen,which seeps out into the air.

Rhizoid A root-like structure in plants suchas mosses. Rhizoids may anchor a plant tothe ground, absorb water, or both. Unliketrue roots, rhizoids do not contain vasculartissue (xylem and phloem).

Rhizome A horizontal stem that growsbeneath the ground. Shoots and rootsgrow from the rhizome.

Root The part of a vascular plant ( 15) thatnormally grows below ground. Rootsanchor a plant and take in water anddissolved minerals from the soil. The firstroot to grow is the primary root, whichthen sprouts sideways lateral roots.

Root hairs Fine growths at the tip of eachroot. They increase the surface area ofroots so they can take up more nutrients.

Simple leaf A leaf not divided into leaflets.

Shoot A new growth on part of a plant.

Stem The long, stiff part of a vascular plant( 15) that supports its leaves, flowers, fruitsor cones. It contains tissues that carrywater and nutrients around the plant.

Stoma (plural: stomata) A tiny hole on theunderside of a leaf, through which carbondioxide enters and oxygen seeps out.

Tendril A modified leaf used by climbingplants to wrap around objects for support.

Transpiration The controlled release ofwater as vapour through a plant’s stoma.Loss of water in the leaves creates suction,which draws up water from the roots. This water carries nutrients absorbed bythe roots around the rest of the plant.

Vascular tissue Xylem and phloem tissuesthat carry water, and minerals and sugarsdissolved in it, around vascular plants ( 15).

Veins Xylem and phloem cells in a leaf thatsupport its structure and transport waterand nutrients to all of its cells.

Xylem The tissue in vascular plants ( 15)

that carries water and dissolved mineralsfrom a plant’s roots to the rest of theplant. This liquid is called sap.

Tropism The growth or slight movementof a plant in response to a change in itsenvironment. For example, phototropismis the movement of a plant towards oraway from light and geotropism is thegrowth of a plant in response to gravity.

Tuber A thick, underground stem or rootthat stores food for the next growingseason. Potatoes are a type of stem tuber.

The edible part of a carrot

is its primary root.

Chloroplast Vein

Stoma

Sunlight

Carbondioxide

Stem

Water andnutrients

Roots

Leaf

Oxygen

Watervapour

Flower

1716

Epidermis

Pallisadelayer

Spongy mesophyll layer

Animal dispersal The scattering of seeds byanimals. Fruits are eaten by animals, whichdisperse seeds in their droppings. Nuts areoften buried and, if left uneaten, maygerminate. Alternatively, seeds may latchon to animals’ fur using hooks or barbs.

Anther The bag-like part at the tip of astamen, where pollen is produced.

Asexual reproduction Reproductioninvolving one parent plant, withoutpollination. A new shoot or root developsinto a new plant identical to the parent.

Ballistic dispersal The explosive dispersal of seeds. The fruit squeezes to fling itsseeds as far away as possible.

FFLLOOWWEERRSS &&SSEEEEDDSS

The main function of a flower is toreproduce—make seeds which growinto new plants. A typical fower has

both male and female parts. The maleparts produce tiny grains of pollen, whichmust reach the female parts of a flower ofthe same kind. The male cell will fusewith, or fertilize, the female cell, and thefemale parts will then start to developinto seeds. Seeds have a better chance ofgrowing away from their parent plant, somany are adapted to be dispersed bywind, water or animals.

Berry A small, fleshy, stoneless fruitcontaining one or many seeds. Berriesinclude tomatoes and gooseberries.

Bulb A round, underground stem with thickleaves emerging from the top and rootsemerging from the bottom. The leavesstore food between growing seasons.Tulips and onions grow from bulbs.

Carpel The female reproductive organ of aflower, consisting of an ovary, style andstigma. Some flowers have one carpel,while others have a cluster of carpels,called a pistil.

Catkin A dangling cluster of flowers thatdisperse pollen via the wind. Catkins arefound on willows, birches and oak trees.

Coconut The fruit of a coconut palm tree ( 19), a seed surrounded by a husk. It may fall into the sea and float to otherbeaches where it grows into more trees.

Cotyledon A leaf-like structure, otherwiseknown as a seed leaf, that is present inside a seed before it germinates. After germination, the cotyledons beginthe process of photosynthesis.

Dispersal The process by which a plantscatters its seeds.

Embryo A young plant inside a seed.

Endosperm The part of a seed where foodis stored for the developing embryo.

Filament A stalk-like part of a flower thatholds the male anther.

Flower The reproductive part of aflowering plant. Some flowers have bothmale and female organs, while othershave only one or the other.

A coconut floating towards a beachwhere it may grow into a new tree.

Seed A small case, containing anundeveloped plant embryo and a supplyof food. This provides energy for theplant to grow until it develops the abilityto photosynthesize.

Sepal A small, green, leaf-like structurebeneath the petals of a flower. The sepalsprotect the flower when it is in bud.

Fruit An outer coat surrounding a seed orseeds. It is formed from a flower’s ripeovary and may be soft or hard. Somefruits have tasty flesh that attractsanimals to eat them so they will disperseseeds in their droppings.

Germination The growth of a plant from aseed. Germination requires water, oxygenand a favourable temperature.

Nut A fruit with a very tough outer case.

Ovary A flower’s female reproductiveorgan where egg cells, or ovules, areproduced. Once the eggs are fertilized bymale cells (pollen), the ovaries begin toenlarge into fruit.

Petal A leaf-like structure surrounding thereproductive parts of a flower. Together,the petals of a flower form the corolla.Petals are often brightly coloured to attractinsects, which pollinate flowers as theymove from plant to plant to drink nectar.

Pollen Tiny, dust-like particles produced byanthers. They contain the male sex cells.

Pollination The transfer of pollen from themale to the female parts of a flower. Pollengrains are light and many are carried in theair. Others are sticky and carried by animalsthat drink nectar from flowers.

Wind dispersal The movement of seedsaway from the parent plant via the wind.Some seeds, such as dandelions, havefluffy “parachutes” to help them stay inthe air and therefore drift further away.Others, such as sycamores, have “winged”seeds that twirl awayfrom the tree as they fall.

FF AA CC TT FF II LL EE

Spores Tiny, dust-like particles that growinto new plants. Non-flowering plants such as ferns reproduce using spores, as do fungi ( 14). Each spore contains DNA ( 12)

contained within a protective coat.

Stamen The male reproductive part of aflower, consisting of an anther and filament.

Stigma The part of the carpel at the end ofthe style, were pollen is received.

Stone A large hard seed inside a fleshy fruit.

Style The long, thin part of the carpelconnecting the ovary to the stigma.

Testa The protective layer around a seed,also known as the seed coat.

Water dispersal The movement of seedsaway from their parent plants via water.Most aquatic plants and some land plantsuse water as a means of dispersal.

This strawberry plant hasgrown a new shoot thathas developed into a newplant. This is known asasexual reproduction.

Avacado fruitOrange

Peas

Walnut

Seeds and pollen carriedby the wind

Dandelion Sycamore Catkin

Pollen grain

Stigma

Style

Ovary

Anther

Filament

Petal

THE REPRODUCTIVE PARTS OF A FLOWER

FRUITSWhen a seed germinates, its rootsspread downwards and the shootarches up and straightens. The cotyledons then openout and beginphotosynthesis.

GERMINATION

! Some seeds, such as those of apples, do not germinate until they have been incold temperatures for a length of time. This shows that winter has passed andconditions are right for growing.

! A few seeds, such as those of theironwood tree, do not germinate unlessthey have been scorched by fire. Other plants will have been burnt, so theground is bare and ready for new life.

! The largest seed in the world comesfrom the giant fan palm. One fruit weighsup to 20 kg and takes around 10 years to grow to its full size.

! The smallestflowering plant inthe world is theWolffia globosa. It is 0.6 mm long and 0.3 mm wide.

1918

Bark The tough outer layer on the stem oftrees, shrubs and vines. The outer barkprotects against damage, cold and waterloss. The inner bark, or phloem ( 16),carries sugars made in the leaves aroundthe rest of the tree.

Branch A division of a tree trunk thatsupports twigs, leaves, flowers and fruit.

Broadleaf tree A flowering tree thatproduces fruits with seeds inside. Manybroadleaf trees are deciduous but some,such as holly, are evergreen.

TTRREEEESS

Atree is a tall perennial plant ( 15)

with a woody stem and brancheshigh above the ground. Its

branches, which divide into smaller twigs,spread out leaves so that they all receive asmuch sunlight as possible. The roots belowground anchor the tree and soak up waterand nutrients from the soil. There are twomain kinds of tree: broadleaf trees andconifers. Different trees have leaves ofdifferent shape. These are often theeasiest way to tell different species apart.

! The largest tree in the world is thegiant sequoia in California. More than 90 m tall and possibly more than 3000years old, it is 25 times heavier than thelargest animal, the blue whale.

! The science of trees is calleddendrology.

! Trees are a valuable resource. Theygive us fuel, timber, medicines, food,paper, rubber and even soap. Even moreimportantly, they take in carbon dioxideand give off oxygen, maintaining thebalance of gases in the atmosphere.

Cone The reproductive parts of aconiferous tree. Conifers have male andfemale cones. When ripe, the male conereleases pollen, which is carried by thewind to female cones. Seeds then developinside the female cone while on the tree.

Coniferous tree A tree, such as a pine orfir, that grows its seeds inside cones andhas needle-like leaves. Coniferous treestypically have a narrow, conical crownshape. Almost all coniferous trees areevergreen but some, such as larches, are deciduous.

Crown The upper branches and leaves of a tree. Each species has a characteristicshape based on the number and angle ofits twigs and branches. Most crowns eitherhave a rounded or crown shape.

Palm tree A treewith a straight trunkand no branches. At the top is a crown oflarge leaves. Palm treesmay grow up to 40 m tall,mostly in tropical and sub-tropical areas.

Resin A sticky substance produced bytrees. Resin helps to seal any wounds inthe trees’ bark to protect it from infection.It also traps insects to stop them fromeating the plant’s wood.

Sapwood The layer inside a tree beneath the growth layer. The sapwood carrieswater from the roots up to the leaves. A new layer of sapwood grows each year,appearing as a ring.

Trunk The main stem of a tree. A treetrunk has several layers: the outer bark,inner bark, growth layer, sapwood and heartwood.

Twig A small division of a branch. Leaves, flowers and fruits grow from buds on twigs.

FF AA CC TT FF II LL EE

A deciduous tree through the seasons

If you look at thestump of a freshly cut-down tree, thesapwood that is

added to the growthlayer each year appears

as a single ring. Count thenumber of rings and you will

find the age of the tree.

Deciduous A tree, such as an oak, mapleor birch, that sheds its leaves in theautumn. This allows it to conserve waterduring the cold months. In the spring itgrows new leaves.

Endogenous tree Any tree that grows new wood interspersed with old woodfibres, rather than in a specific area of new growth. Endogenous trees includepalms and cacti.

Evergreen A plant, such as a pine or holly,that has leaves all year round. Evergreenplants constantly lose and replace theirleaves throughout the year.

Exogenous tree Any treethat grows in width byforming new layersof wood under theinner bark each year.Most trees areexogenous.

Growth layerA layer of a plant’strunk just beneaththe inner bark. It makes new barkon the outside andnew sapwood on the inside.

Heartwood The inner core of a tree’s trunk made of old, hardenedsapwood. The heartwoodgives a tree its strong“backbone”.

Palm tree

Winter Spring Summer Autumn

A giant sequoia, thebiggest tree on Earth.

Conifer treeand cone(below)

Water (red) is drawn up from the soilto the leaves through the sapwood.Sugar made by photosynthesis (blue)passes from the leaves to the rest ofthe tree through the inner bark.

Roots

SapwoodGrowthlayer

Innerbark

Outerbark

LAYERS OF ATREE TRUNK

2120

Growth layer

Heartwood

Bark

Annual ringSapwood

Leaf

Alpha animal An individual that leads andinfluences the rest of its group. The alphahas the best food and the first pick ofmates. He or she is often the largest,strongest or oldest member of the group.In some species, such as baboons, thealphas all descend from one “royal” family.

AANNIIMMAALL BBEEHHAAVVIIOOUURR

Animal behaviour includes all thethings an animal does and how itdoes them, including finding food,

avoiding predators, mating and breeding.It also examines the relationship ofanimals to their environment and to otheranimals. Some animals live in complexsocial groups. Others are usually solitary,but will group together to mate or raisetheir young. Most animal behaviour isdirected towards increasing the chancesof an animal’s survival.

! Animals of the same species living indifferent regions may have varying“dialects” in the calls they use.

! Many animals use body language andfacial expressions to communicate with one another. For example, maintaining eye contact, or staring, is a sign ofaggression in many species.

FF AA CC TT FF II LL EEHoneybees form eusocial colonies.

Most bats are nocturnal. They live in large groups indark places such as caves or trees.

Meerkats aresocial animals.They live ingroups of 30 orso and take turnsto watch out forpredators.

Commensalism A relationship betweentwo living things in which one benefitsand the other is unaffected. For example,jackals sometimes follow tigers, feedingon the remains of their kills.

Competition The struggle for survivalwithin or between species as theycompete for limited food, water orterritory. Competition allows naturalselection ( 11) to occur, with animalsbetter suited to their habitat and lifestylebeing more likely to survive.

Courtship Behaviour used to attract a mate. Some animals, especially birds, haveelaborate courtship behaviour, ofteninvolving “dances”. It helps the animals toselect partners that are sexually mature,strong, fit and healthy.

Imprinting A form of learning where somenewborn birds or mammals recognize andfollow the first moving thing they see,usually a parent.

Nest A structure built by an animal or insectin which it cares for its eggs or young.

Symbiosis A relationship betweenmembers of two species in which one orboth benefit. For example, clownfish liveamong the vemomous tentacles of seaanemones which do not harm the fish butkill its enemies. The anemone may feed onanimals attracted to the clownfish.

Territory An area that an animal or groupof animals defends against others of itskind. This removes competition for foodand protects young from potential danger.Animals mark their territory by leavingtheir scent around its borders, or bymaking loud calls.

Nocturnal Active during the night andinactive during the day. In hot areas,animals may be nocturnal to avoid theheat of the day. Some animals, such asbats, hunt at night to avoid competitionwith others—in the case of bats, birds.

Parasite A living thing that depends onanother living thing (a host) for needssuch as food and shelter.

Parasitoid A parasite that kills its host.The young of some insects are parasitoid.

Social animals Animals that live in groups.They may share tasks such as finding foodor looking out for predators. A few kindsof animals, such as wolves and lions, worktogether in packs to hunt.

Echolocation The method by which someanimals, such as bats and whalessometimes navigate and find theirprey. They emit high-pitchedsounds and listen to the echoes tobuild up a picture of their surroundings.

Ethology The study of animal behaviour.

Eusocial animals Animals that live in tightlyorganized units and depend on oneanother for survival. Different groupswithin the unit are responsible for certaintasks such as finding food, raising young ordefending the group. Most eusocialanimals are insects, such as ants and bees.

Fixed action pattern Instinctive animalbehaviour as a result of an animal’s genes ( 10). For example, it is thought that some bird courtship displays are fixedaction patterns.

Hibernation The process whereby somemammals spend winter in a state ofreduced body activity. Body temperaturedrops significantly, enabling the animal to conserve energy.

Imitation Behaviour where an animalcopies another animal’s actions. In the1980s, researchers observed one Japanesemacaque (a monkey) washing her food in the river, rather than brushing it off likeother macaques. This useful behaviour was soon imitated by those around her.

Clown fish andanemoneChimpanzees live together in

groups and defend theirterritory against other groups.Grooming one another helps tostrengthen the bonds betweengroup members.

2322

A male and female albatrossperform their mating “dance”

Birdsong The musical calls made by somespecies of bird in order to mark out theirterritory or attract a mate. Birds also makeshorter calls to alert others to danger.

Brood parasite An animal that tricks otherspecies into raising its young. For example,cuckoos lay their eggs in the nests of otherbirds. The young hatch and push the eggsaround them out of the nest, securing allof the nestlings’ food for themselves.

Circadian rhythm A 24-hour body clockthat guides the behaviour of mostorganisms, affecting patterns such as sleepand digestion. Circadian rhythms continueregardless of light and dark.

Colony A group of one kind of animal living together. Some animals, such as

ants, form permanent colonies, co-operating to feed and breed as

part of a unit. Other animalsgather only to breed.

Red foxes can be very territorial,fighting any other foxes that

stray into their territory.

Aerial movement Movement through theair by flying or gliding. Very small animals,such as insects, may also be picked up andcarried by the wind.

Arboreal movement Movement throughtrees. Many arboreal mammals have longlimbs to reach across gaps and sharp clawsto grip bark. Frogs and lizards cling to treeswith their sticky finger pads, and snakes usetheir muscular bodies to climb branches.

AANNIIMMAALLMMOOVVEEMMEENNTT

One of the key features of ananimal is its ability to movearound. Most creatures can run,

walk, jump, hop, slither, swim or fly.Limbs are not vital for movement. Snakes are limbless, yet they can slitheron the ground, swim in water and evenclimb trees. A few animals do not moveabout, at least as adults. For example,barnacles are stuck to seashore rocks,

although they were mobile whenthey were young.

FF AA CC TT FF II LL EE

A cheetah, the fastest land animal in the world

A spider monkey usesits prehensile tail tohelp it move throughthe treetops.

A sidewinder (above) moving over desert sand

A kangaroo pushes off with its backfeet and leans forwards as it leaps into

the air. Its long tail helps keep it balanced.

BrachiationA type of arborealmovement used bymonkeys to swing bytheir arms from branchto branch.

Fin A broad, flat surfaceprojecting from the bodyof aquatic animals, including fish andwhales, used for steering and balance.

Flipper A specialized limb in a marinemammal, such as a seal, used to propel itthrough the water.

Flying Movement through the air usingwings. Only birds, bats and insects can fly.They flap their wings down to create alifting force, and back to push themselvesforward. There are two kinds of flappingflight: hovering and forward flight.

Gait The pattern in which an animal movesits limbs. Most animals have several gaitsused for different speeds or terrain. For example, a horse may walk, trot, canter or gallop. In each gait, the horse

moves its limbs in a different way.

Limbless movement Movement in water oroverland without the use of legs. Limblessanimals use muscles in their body to propelthemselves forward. Snakes slither or swimusing undulatory motion. Snails and slugscrawl on one slimy foot. Earthworms useperistalsis and leeches use looping.

Looping A type of movement used by somecaterpillars and leeches. The animal securesits rear end and reaches foward with itsfront end. With the front of its body inplace, it pulls forward its rear end to form aloop and starts the cycle again.

Muscle A body part that gets shorter, orcontracts, to move another body part.

Undulatory movementA wave-like motion that pulls an animal’sbody into an S-shape. Undulatory motion is how snakes crawl and eels swim

Walking The slowest gait in terrestrialbipedal or quadrupedal movement. Whenwalking, at least one foot is always on theground. In contrast, during running, all thefeet may be off the ground at once.

Wings A pair of structures that enable ananimal to fly by flapping. In birds andmammals these are modified front limbs.Birds have feathered wings. Bats’ wingsare made of skin stretched between theirlong fingers. Most insects have one or twopairs of wings.

Quadrupedal An animal that moves on twolegs. Most land mammals are quadrupedal.

Sessile An animal that is not able to moveabout as an adult. For example, musselsare stuck to seashore rocks, but weremobile during their young stages.

Sidewinding Sideways, undulatory motionused by some snakes to ease movementacross sand or slippery surfaces. In thedesert, snakes may sidewind so that onlyone patch of their body is in contact withthe hot sand at a time.

Soaring A type of flight used by some largebirds, such as eagles, to stay in the air,seldom flapping their wings. Soaring birdsuse rising air currents to keep them aloft.They can fly for many kilometres in thisfashion, using little energy.

Swimming Movement through water.Aquatic creatures must be streamlined sothe water slips past them easily. Fish suchas sharks swish their tails from side to sideto provide a forward propulsive force,while whales move them up and down.Other aquatic animals, such as eels, moveby undulation. Aquatic birds and turtlesflap their limbs to “fly” through the water.

Streamlined A smooth shape that reducesair or water resistance. Animals that fly orswim must be streamlined so that the airor water slips past them easily and theyuse less energy to move through it.

Terrestrial movement Movement overland, by walking, running, crawling,jumping or slithering.

Gliding Controlledfalling motion through the air,

used by some forest animals.Gliders cannot power their flight, but

use flaps of skin, stretched betweenlimbs like parachutes, to slow their

descent. Gliding animals can steer butcannot glide upwards.

Hovering The act of staying in one positionin the air, achieved by some flying animals,such as hummingbirds. Hovering uses avery quick flapping motion and burns upmuch more energy than forward flying.

Jet propulsion A type of movement usedby jellyfish, octopuses and squid. Water issucked into the animal’s body sac andsquirted out at speed, propelling theanimal in the opposite direction.

Jumping A type of movement used byanimals such as kangaroos, rabbits andfleas. Jumping animals have long backlegs, used to power them forward.

Bipedal An animal that moves ontwo legs. Apes and large birds put oneleg in front of the other. Others, such askangaroos, hop on two legs. A few species,such as the basilisk lizard, may run on twolegs in short bursts, to escape predators.

Rabbitfish swimming

Peristalsis Wavelike muscle contractionsdown a tube. Earthworms, use peristalsis tocrawl forwards.

Prehensile Capable of grasping. Someanimals, such as monkeys, have aprehensile tail, used as anextra limb when climbingthrough the trees.

Duck flying

Penguins swimming underwater

! The fastest land animal, the cheetah,sprints at more than 100 km per hour. Its sharp claws, which are permanentlyextended, act like spikes on running shoes,providing good grip on the ground.

! The fastest marine animal is the sailfish,which can reach speeds of up to 110 km/h.

! A vulture, followed by scientists in amotorized glider, was observed gliding 75 km without flapping its wings once.

! Hummingbirds are the fastest-flappingbirds, using up to 80 wingbeats per second.

! Most gliders,such as this sugarglider (right), areable to soar up to 90 mbetween tree branches.

2524Caterpillars looping

along a branch

AATTTTAACCKK &&DDEEFFEENNCCEE

Meat-eating predators obtaintheir food by hunting andattacking other creatures: their

prey. Most predators are strong and agile,with keen senses and weapons such assharp teeth and claws. Animals use avariety of means to defend themselves.Some have hard bodies, spines or foul-tasting flesh. Some use speed to escape,while others may fight back, kicking outwith hooves or charging with tusks orhorns. Safety in numbers also helps—many eyes and ears are more likely todetect predators.

Armour A hard body covering that helpsprotect animals. Armour may take theform of a hard shell, as in tortoises, oroverlapping scales, as in armadillos. Somereptiles also have armour-like, scaly skin.

Autotomy The action of deliberatelylosing a body part, used by some animalsto distract predators while they escape.For example, some lizards can shed thetip of their tail, which continues to twitchas the lizard runs away. Insects andspiders shed their limbs in a similar way.

Camouflage The means by which animalsescape the notice of predators or prey,using their colours, patterns or bodyshape to blend in with their surroundings.

Countershading A type of camouflageused by many fish. A dark back enablesthe fish to blend in with the depths whenseen from above; a pale undersideenables it to merge with the light surfacewaters when seen from below.

Mimicry A similarity between two speciesthat protects one or both of them. Someanimals mimic other, more dangerousspecies, in order to scare off predators. For example, some harmless flies havesimilar markings to bees and wasps.

Warning colours Bright colours andmarkings that warn that an animal tastesbad or is poisonous to eat. Certain fish,beetles, caterpillars, moths and butterflieshave horrible-tasting or poisonous flesh.Predators soon learn to avoid thembecause they recognize their colours.Warning colours may also signal that ananimal is venomous. For example, severalvenomous snakes are brightly coloured.

Porcupine

Spines Sharp, needle-like protrusions onthe body of animals such as hedgehogs,porcupines and porcupine fish. Whenthreatened, a porcupine curls into a ball orbacks into its attacker, leaving spinesembedded in its attacker’s skin.

Startle display A sudden action intendedto intimidate or startle an attacker. Someanimals flash bright colours or patterns tostartle predators. Other animals suddenlypuff up to make themselves appear larger,or leap out to scare their predator.

Sting A short, sharp organ belonging tosome animals, such as bees, ants andscorpions. Stings inject venom into otheranimals, in order to paralyze or kill prey,or harm attackers.

Venom A poisonous substance found inthe bodies of some animals, includingspecies of snake, spider, scorpion and fish.It can be used for killing prey or defence,and is usually injected with a sharp stingor bite. Venomous predators may givewarning that they are about to strike.

A group of female lions ambush a wildebeest.

The talons of an owl are suited to snatching up prey.

Ambush A surprise attack. In an ambush, a predator hides until its prey approaches,when it suddenly darts out. Ambushes useless energy than long chases.

Apparent death A type of self-defencewhere an animal feigns death ifthreatened. This deters those predatorsthat prefer to make their own kill. Many snakes feign death. The Virginiaopossum also uses apparent death, also called “playing possum”.

The countershading ofa tiger shark

Prey An animal that is hunted and eatenby other animals.

Pronking A sudden, stiff-legged leap intothe air, used by some herd animals,especially gazelles, as they run frompredators. It is thought to be a signal tothe pursuing predator that the individualis fit and the predator would do better tochase another animal in the herd.

Adrenaline A chemical released into thebloodstream when an animal sensesdanger. It makes the heart beat faster,sending more blood around the body, sothe muscles can work harder.

Chemical defence A form of self-defencewhere an animal sprays toxic liquids overits attacker. This is common in insects andin some mammals, such as skunks.

A copperhead pit viper uses its yellow tail tip toattract small animals, then strikes with its fangs.

Mobbing behaviour An attack launchedby a group of animals in order to driveaway an attacker. Mobbing is common inanimals such as nesting birds, whoseyoung are at risk.

Pack-hunter A predator that hunts as partof a group. Pack-hunters increase theirchance of success by surrounding prey, orworking to bring down large prey.

Predator An animal that kills and eatsother animals.

Musk oxen form a circle around theiryoung to defend them from wolves.

The caterpillar of a hercules moth is brightlycoloured and covered in spines in order to deter

predators from eating it.

FF AA CC TT FF II LL EE

2726 The harmless milk snake (above) mimics thebright colours of the venomous coral snake.

! When attacked, a sea cucumber cansquirt out its insides as a distraction whilstit escapes. It later grows them back!

! Most predators depend on stealth tocreep up on prey. Owls’ feathers have softedges so they make hardly any sound asthey fly. Cat’s paws enable them to padsoftly over ground without being heard.

! Plants also need defences from beingeaten by animals. Because they are rootedto the ground, they cannot escape. Somevarieties, such as cacti andbrambles, have spinesthat make them difficultto eat. Some, such asstinging nettles, havestinging hairs that makethem painful for animalsto touch. A few plants are poisonous or tastefoul to stop animalseating them.

Complete migration A migration whereall members of a species migratetogether. Complete migrations aretypical of caribou (reindeer) and manybirds, including warblers andshorebirds.

Homing The ability of an animal totravel towards a set location, such as ahome or breeding ground, from anunfamiliar starting point. Homingmay depend on celestial,magnetic or olfactorynavigation. Pigeons are well knownhoming birds.

Irruption Anymigration thatoccurs at randomintervals.Irruptions mayinvolve some,many or all of a population.For example, lemmings are knownfor their irruptive migrations, whichoccur if there is a shortage of food, orif they become overcrowded.

Latitudinal migration The movement ofanimals north and south to differentclimates. In the northern hemisphere,the north is colder than the south, andmany animals migrate south for thewinter. Animals return in the summerwhen the north is warmer and food isplentiful once more.

Altitudinal migrationThe movement of animals from a

high altitude to a lower one, for exampleup and down a mountain. Many animalsleave mountain peaks in winter as plantsbecome covered in snow.

Celestial navigation Navigation using thestars, sun and moon. For example, it isthought that starlings navigate using thesun to tell which direction they are flyingin. Warblers, flycatchers and other night-time flyers are throught to navigate byreferring to the position of the stars.

Compass navigation The ability of ananimal to travel in a compass direction, for example north, without reference tolandmarks and regardless to starting point.

MMIIGGRRAATTIIOONN

Migration is the movement of an animal or a group of animals from one place to

another. This usually takes place once ayear, in a certain season. Animals maymigrate to find food or to reachconditions more suitable for breeding.Migrations take place over land, by airand by water. Birds migrate the farthest,because flight enables them to coverlong distances. An animal that migrates

is called a migrant.

! Caribou (reindeer) migrate fartheroverland than any other animal, walkingup to 1300 km every spring from theconiferous forests of Canada to theirsummer pastures in the Arctic.

! Many migrating animals feedintensively before migrating, in order tobuild up their fat reserves for the journey.

! A willow warbler’s body holds enoughenergy to enable it to fly 6o hours non-stop. This enables it to fly across desertsand seas on its migratory route.

FF AA CC TT FF II LL EE

Navigation The ability ofan animal to travel from one

point to another

Nomadic migration The randommigration of animals in search of

food. For example, wildebeest andzebras migrate nomadically across the

African plains. Once they have eaten theplants in one area they move to another.

Olfactory navigation Navigation thatrelies on mental maps based upon scent.Olfactory navigation is usually used oversmall distances. Salmon and some species

of salamander are believed touse olfactory navigation

during migrations.

Partial migrationThe migration of just some

members of a species, usually to breed.The herring gull, red-tailed hawk andgolden eagle are all partial migrants.Partial migrations are much morecommon than complete migrations.

Removal migration A migration where aspecies permanently leaves its originalenvironment. Removal migrationstake place when an environmentis destroyed or if there is notenough food to go round.

Seasonal migrationMigration that matches the change in seasons.Most animal migrationsare seasonal.

True navigationNavigation that depends on

recognition of major landmarkssuch as rivers, mountain ranges or evenroads and cities. Marine animals, such asdolphins, navigate by remembering theshape of the ocean floor.

V-formation A pattern formed bymigrating birds in the air in order to saveenergy. Air movements caused by theflapping of the bird in front provide extralift for the birds behind it. Geese, ducks,pelicans and cranes all fly in this formation.

Each year, swarms of locusts fly3200 km around the Sarhara desert.

in a nomadic migration.

Every autumn, monarch butterflies migrate fromCanada to Mexico, where they cluster in theirmillions on tree trunks.

Golden ploversmigrate from Brazilto northern Canada

and back, a roundtrip of 40,000 km.

Magnetic navigation Some animals candetect the Earth’s magnetic field and use itas a guide when they migrate. Bats, seaturtles and birds use magnetic navigation.Scientists think they can do this becausetheir brains contain tiny particles of amagnetic mineral called magnetite.

Migrating caribou often haveto swim across rivers to reach their destination.

The willowwarbler’smigration takes itfrom Siberia to thesouthern tip ofAfrica each winter.

Painted ladies are thefarthest-travelled Old

World (not fromAmericas) butterflies.

2928

The noctule bat flies up to1600 km across eastern

Europe in the spring.

Caribou(reindeer)

Monarchbutterfly

Goldenplover

Monarchbutterfly

NORTHAMERICA

SOUTHAMERICA

EUROPE

AFRICA

ASIA

Paintedlady

Desertlocust

Noctulebat

Willowwarbler

AAadaptation 10-11adaptive radiation 10adrenaline 26algae 12-13, 15

brown 8golden 8green 8, 15red 8

alpha animal 22ambush 26amoebae 8, 12-13analogous structure 10angiosperm 8, 14 animal movement 24-25

aerial 24arboreal 24limbless 24terrestrial 25undulatory 25

animals 6-11, 22-29behaviour in 22-23courtship in 22-23methods of attack by 26-27methods of defence by 26-27

anther 18-19apicomplexa 8, 12apparent death 26archaea 6-8armour 26artificial selection 11asexual reproduction 16, 18-19Aspergillus 12autotomy 26

BBbacillus 12bacteria 6-8, 12-13bark 20-21, 24berry 18bipedal 24-25birdsong 22brachiation 24

branch 16, 20-21breeding 22, 28bromeliad 14bryophyte 8, 14-15bud 16, 19bulb 18

CCcactus 14-15, 20, 27camouflage 11, 26carbon 6carbon dioxide 13, 16-17carpel 18-19catkin 18-19cells 6-7, 10, 12-13, 16-19chemical defence 26chlorophyll 16chloroplast 16-17cilia 12-13ciliate 8, 12circadian rhythm 22class 6-9classification 6-9clubmoss 8, 14coccus 12coconut 18-19colony 22commensalism 22competition 22-23cone 14, 17, 20conifers 8, 20corolla 19cotyledon 14-15, 18-19countershading 26crown (tree) 20-21cyanobacterium 12cycad 8, 14

DDDarwin, Charles 10-11deciduous 20diatoms 8, 12dicot 8, 14-15Didinium 12digestion 11, 22

dinoflagellate 8, 12disease 13dispersal 18-19

animal 18ballistic 18water 19wind 19

division 7, 8-9DNA 7, 10, 19domain 6-8

EEecholocation 23embryo 11, 18-19embryology 10endosperm 18epidermis 16-17epiphyte 14ethology 23Euglena 12eukaryotes 6, 8-9eusocial animals 23evergreen 20evolution 10-11

convergent 10divergent 10parallel 11

extinction 10

FFfamily 6-7fern 8, 14, 16, 19fertilization 18-19filament 18-19fin 24fixed action pattern 23flagella 13flipper 24flowers 14, 16-19, 21flying 24-25foliage 16foraminiferan 8, 13fossils 10-11frond 14, 16fruits 14, 17, 18-21

fungi 6-9, 12-15, 19club 8imperfect 8sac 8

GGgait 24genes 10-11, 13, 23genetics 11genus 6-7geotropism 17germination 14, 18-19ginkgo 8, 14gliding 24-25gnetophyte 8, 14growth layer (tree) 20-21guard cells 16-17gymnosperm 14

HHheartwood 20-21heliozoan 8, 13hemiparasite 14heredity 11hibernation 23homing 28homologous structure 11hornwort 8, 15horsetail 8, 15host 23hovering 24hybrid 7hyphae 15

IIJJKKimitation 23imprinting 23inheritance 11irruption 28jet propulsion 24jumping 24-25kingdom 6-9, 14

LLleaflet 14, 16-17leaves 14-15, 17, 18, 20-21

compound 16-17simple 15, 17

lichen 15limb 24-25Linnaeus, Carolus 7liverwort 8, 14-15looping 24

MMmating 22Mendel, Gregor 11mesophyll 16micro-organisms 12-13migrant 28migration 28-29

altitudinal 28complete 28latitudinal 28nomadic 29partial 29removal 29seasonal 29

mildew 6mimicry 26-27minerals 7, 16mobbing behaviour 27monocot 8, 15moss 8, 15mould 6, 8, 14-15multicellular 12-13muscle 24mushroom 6, 14-15mutation 10-11mycelium 15

NNOOnatural selection 10-11, 22navigation 28-29

celestial 28compass 28magnetic 28olfactory 28-29true 29

nest 23nocturnal 23nucleus 6-7, 12-13nutrients 14nut 18-19

OOorder 6-7organelles 6, 12-13organisms 8-13, 15, 22

single-celled 6, 12-13ovary 18-19oxygen 16-17, 19

PPpack-hunter 27palisade layer 16-17palm tree 18-20parasite 23

brood 22parasitoid 23peristalsis 25petal 14-16, 18-19, phloem 16-17, 20photosynthesis

7, 12-19, 21phototropism 17phylum 6-9pistil 18plants 6-8, 11, 14-15, 19

annual 14aquatic 14, 19biennial 14carnivorous 14, 16coniferous 15flowering 14functions of 16-17herbaceous 15non-vascular 15parasitic 15perennial 15, 20succulent 15vascular 15, 16-17

pollen 18-20pollination 18-19predator 26-27

30 31

prehensile 24-25prey 26-27prokaryote 13pronking 27protein 13protists 6-8, 12-13protozoan 12-13

QQRRquadrupedal 25rank 6-7reproduction 7resin 21respiration 7rhizoid 16rhizome 17root hairs 17roots 15, 16-21

primary 17vascular 17

running 25

SSsap 17sapwood 21scientific name 7seed coat 19seed leaf 18seeds 14, 16, 18-20sepal 19sessile 24-25sexual selection 10-11shoot 17, 19shrub 14-15, 20sidewinding 25soaring 25social animals 23speciation 11species 6-7, 10-12, 14-15,

17, 20, 22-24, 26-29 spirillum 13spongy mesophyll

layer 16-17spores 6, 14-16, 19stamen 18-19startle display 27stem 15, 16-18

stigma 18-19sting 27stoma 14, 16-17stomata see stomastyle 18-19subspecies 7, 10swimming 24-25symbiosis 23

TTtaxonomy 6-7tendril 17territory 22-23testa 19toadstool 8, 14-15transpiration 16-17trees 14, 19, 20-21

broadleaf 20coniferous 20endogenous 20exogenous 20palm 21

tropism 17trunk 20-21tuber 17twig 21

VVvariations 10-11vascular tissue 16-17venomous 23, 27vestigial organ 11v-formation 29vine 15, 20virus 12-13Vorticella 13

WWXXYYwalking 24-25Wallace, Alfred Russel 11warning colours 27wings 25xylem 16-17yeast 6, 13, 14

IINNDDEEXX