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2.1 Different kinds of animals1. Unicellularanimalsdonothaveanytissuesandorgans.Whichpartsof

theseanimalsperformthenecessarylifeprocesses?

2. Whoareamoebaenamedafterandwhy?

3. Oneofthecharacteristicsof life isreproduction.Whydounicellularandbilayeredanimalsjustsplitthemselvesupwhentheyreproduce?

4. Readtheextensionbox‘Howdoamoebaemove?’.Usethisinformationtoshow,usingthreesequentialdrawings,howanamoebacatchesitsfood.

The cell organelles

After the Greek God Proteus. He was able to change shape.

Unicellular and bilayered animals do not have specialised organs

for reproduction.

The teacher checks the drawings. This is an example of a correct drawing.

23

5. Inthisexperimentyouaregoingtoobserveunicellularanimalsun-derthemicroscope.

What do you need?• Hayinfusion(preparedbyyourteacher)• Materialsforpreparingaslide• Microscope• Drawingpencil• Rubber

Readthedrawingrulesonpage14ofyourtextbook.

What do you have to do?1. Useadroppingpipettetosuckupafewdropsofhayinfusion.Most

unicellularanimalswillgatherinthetoplayerofthehayinfusion,sobesuretocollectyoursamplefromthislayer.

2. Placethedropletofhayinfusiononaslideandpreparetheslideinthewayyoulearnedinchapter1.

3. Drawaleasttwodifferentkindsofunicellularanimalsatthehighestmagnification.Usethetwoseparateboxesbelow.

24

Questions

male sex organ

atrial siphon

branchial siphon

nerve

heart

stigmata

anus

stomach

oesophagus

female sex organ

6. Complexanimalshave specialisedorgansandorgan systems. If youreadtheboxonseasquirts,youwilldiscoverat leasttwodifferentorgansororgansystems.Whichtwo?

7. Theimagebelowshowsabiologicaldrawingofaseasquirt.Someor-gansarelabelled.Thetableonthenextpagelistsfivedifferentorgansystems.Writedownalltheorgansunderthecorrectorgansystems.Someorgansmaybeusedmorethanonce.

Nervoussystem

Circulatorysystem

Respiratorysystem

Digestivesystem

Reproductivesystem

Nerve Heart Branchial siphon

Branchial siphon

Male sex organ

Atrial siphon

Stomach Female sex organ

Stigmata Esophagus

Atrial siphon

Stigmata

Anus

(1) Opening for letting in water containing oxygen and food.

(2) Organs for reproduction.

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Questions

2.2 Swim, walk, fly!

8. Someanimalsareabletomoveandothersareabletoperformlocomo-tion.Whatisthedifferencebetweenthetwo?

9. Plantigradescanwalkeasilyonunstablegroundlikesandandwood-landsoil.Explainwhythisispossible.

10.Youaregoingtoprovethathoofedanimalshaveproblemswalkingonunstablesoilswhileplantigradeanimalsdonot.

What do you need?• Apencil• Alargecoin(e.g.a2eurocoin)• Sand• Asmallplasticcontainer(e.g.amargarinetub)

What do you have to do?1. Usetheitemslistedin‘Whatdoyouneed?’todesignanexperiment

toprove thathoofedanimalshaveproblemswalkingonunstablesoilsandplantigradeanimalsdonot.

2. Writedownadescriptionofhowtheexperimentmustbedone.

3. Maketwodrawingsoftheresultsofyourexperiment.

Locomotion is changing place. Moving from one spot to another.

Movement is moving without changing place.

They use the whole of their feet for walking. Their weight is spread

out over a larger surface area. Therefore plantigrades do not sink

into the ground.

26

Questions

Description of the experiment

Drawings of the results

The teacher checks the drawings.

27

squirrel

plantigrade

deer

unguligradedigitigrade

dog

Questions

11.Althoughplantigrade,digitigradeandunguligradeanimalswalkondif-ferentpartsoftheirfeet,thebuildingplanoftheirlegsissimilar.Theimagebelowshowsthelegbonesofatypicalplantigrade(squirrel),digitigrade(dog)andunguligrade(deer).Usingcolouredpencils,co-lourthesimilarboneswiththesamecolour.

12.Whichisabletorunfastest,aplantigrade,adigitigradeoranunguli-grade?Explainyouranswer.

13.a. Whatisthespecialshapeofabird’swingcalled?

Unguligrades are generally the fastest runners, because they have

the least ground contact with their feet. However the world’s

fastest animal is a digitigrade, the cheetah.

Aerofoil

Questions

28

Questions

Air that travels over the top of the wing goes faster than the wind

that travels under the wing.

The slower moving wind pushes the wing upwards.

b. Explainhow‘lift’works.

14.Whatisthereasonwhybirdsmustpreentheirfeathers?

15.Cartilaginousfishsinkwhentheystopswimming.Whydoyouthinkthisis?

16.Fisharenottheonlyanimalswithtorpedo-shapedbodies.Namethreeotheranimalsthatalsohavethisbodyshape.

The flight feathers must be kept smooth and flat.

This is done by preening which zips the feathers together.

Because cartilaginous fish do not have a gas bladder.

Examples of correct answers: dolphins, penguins and whales.

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Source: natuurinformatie.nl

17.Pictured below are some skeletons of several animals. Write downwhethereachanimalisaplantigrade,digitigradeorunguligrade.

Gorilla ___________________________

Tiger ___________________________

Americanbison ___________________________

Polarbear ___________________________

plantigrade

digitigrade

unguligrade

plantigrade

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Questions

2.3 Feeding time

18.Lookatfigure2.15inyourtextbook.Theskulloftheherbivoredoesnothaveanycanineteeth.Whyisthis?

19.The intestines of herbivores are relatively long in comparison withtheirbodysize.Whydoyouthinkthisis?

20.Thepicturebelowshowsacateatingarat.Whenyoulookcloselyyouseethatthecatisusingthesideofitsmouthtoeat.Explainwhy.

It does not have to hold any prey.

Plants take a longer time to digest because of the cellulose

cell wall.

The carnassials are situated at the side of a carnivore’s mouth.

Carnassials are used to ‘cut’ meat of their prey.

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31

21.Carnivoresdonoteatasoftenasherbivores.Whydoyouthinkthisis?Choosethebestanswer.

A. Carnivoreshavelongerintestinesthanherbivoressothefoodstaysintheirbodylonger.

B. Carnivoreshaveproblemsdigestingmeat. C. Carnivores get more energy out of meat than herbivores get out

of plants.

22.Theimageshowsamolarofananimal.Whatwillitsdietconsistof?Explainyouranswer.

23.Youwilllookatseveralskullsofdifferentanimalstofindoutwhatkindoffoodtheyeat.Thisexperimentwillbedoneingroupsoftwoorthree.

What do you need?• Threeorfourdifferentskulls

What do you have to do?1. Lookcarefullyattheskullsandteethoftheanimal.

2. Writedownwhatyouthinktheanimalseat.Usethewordsherbivore/carnivore/omnivore.

3. Describewhichcluesyouusedtogiveyouranswer.

Plants, the surface of this molar is suited for grinding plants.

Answer will depend on the kind of skulls used.

The teacher should check the answers.

Questions

32

Questions

Skull1isfroma(n)________________because,

Skull2isfroma(n)________________because,

Skull3isfroma(n)________________because,

Skull4isfroma(n)________________because,

Skull5isfroma(n)________________because,

24.Readthetextabout‘Specialists’.

a. Apartfromcatchingants,whatreasoncouldananteaterhaveforflic-kingitstongueupto150timesaminute.

To prevent being stung or bitten by the ants and termites.

Questions

33

b. Istheaye-ayeaherbivore,acarnivoreoranomnivore?Explainyouranswer.

c. Whatadaptationsdoestheaye-ayehaveforreachingtheinsectsinsidethetreetrunks?

It is an omnivore because it eats plants, like the coconuts,

and meat, like insect larvae.

A very long middle finger.

Questions

34

Questions

2.4 Breathing

25.Whichorgandoesafishusetobreathe?Choosethebestanswer.

A. gills B. gillcover C. gill arches

26.Whenfisharetakenoutofthewatertheydie.Notbecauseofdehydra-tion,butbecausetheysuffocate.Explainthis.

27.Readthefollowingtextaboutinsectsandfillintheblanks.

Breathing in insects

Insectsdonotuse lungstobreathelikemammals

orbirds.Insteadtheybreathethroughtracheae.

Thesearetube likeorgansthatrunthroughthe

bodyofaninsect.Theabdomen

haslittleholes,calledspiracles.Biginsectsmust

makeapumpingmovementtorefreshtheairintheirtracheae.

The gill covers sticks to the fish’s skin. The fish is not able to take

in enough oxygen.

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35

28.Togetherwithaclassmateyouaregoingto lookat thegillsofafish.

What do you need?• Dissectingpanordissectingboard• Latexgloves• Forceps(optional)• Dissectingscissors• Dissectingscalpel(optional)• Probe• Teasingneedle• Petridishwithwater• Stereomicroscopeormagnifyingglass• Smallfish(likesardine)ortheheadofabigfish(likemackerel)

What do you have to do?1. Openthemouthofthefishbypushingthelowerjawdown.

2. Liftoneofthegillcoverswiththeteasingneedle.

3. Slidetheprobebetweenthegillcoverallthewaythroughtheopenedmouth.Becarefulnottodamagethegills!

4. Usethescissorstocutthegillcoverloosefromthelowerjaw.Cutfromthebacktothefront.Youhavetocutbothgillcovers.

5. Nowyouareabletobendtheheadofthefishback.Dothisasfaraspossible.Thegillarchesareclearlyvisible.

6. Slidetheteasingneedlegentlybetweenthegillarches.

7. Liftoneofthegillarcheswiththehelpoftheteasingneedle.Youcanusetheforcepstomakethingseasier.

8. Cutthegillarchwhereitisattachedtotheothergillarches.

9. PutthecutgillarchinthePetridishwithwater.

10.Studythegillarchwiththestereomicroscopeormagnifyingglass.

11.Drawabiologicaldrawingofthegillarch.

12.Answerthequestions.

Questions

36

Questions

Depends on the kind of fi sh. The teacher should check the answer.

One.

Only on one side.

Because then the gill fi laments attached to the gill arches will

unfold.

In the water, because then the fi laments are unfolded.

a. Howmanygillarchesdoesyourfishhave?

b. Athowmanyplacesarethegillarchesattachedwitheachother?

c. Wherearethegillarchesattachedtoeachother?

d. Thegillarchisbestobservedwhileitisinwater.Whyisthis?

e. Whenisthesurfaceareaofthegillarchlarger?Whenitisinthewa-terorwhenitisoutofthewater.Explainyouranswer.

Visit the site www.ovdbricks.nl for more dissection on fi sh. Play the digital game and answer the questions.

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37

2.5 Sensing the environment

29.What is the main reason that organisms must sense their environ-ment?

30.Readthesentencesbelowandchoosethebestanswer.

a. Birdsofpreydependonsight/hearingwhilehunting. b. Catsseemore sharply/lesssharplythanhumans. c. Becauseofaspeciallayerintheireyes,catscan/cannotseeinthe

dark. d. Manyreptilesandamphibianshaveathirdeyetosee colour/dif-

ferences in dark or light. e. You are/a kestrelisabletoseethissentenceatarangeof23me-

tres.

31.Whenitisdarkandacat’seyesareflashedwithlight,theywilllightup.Whatisthiscalled?

32.Gotothesitewww.ovdbricks.nl.LookunderBiology,chapter2,sour-ces,fortheclip‘Triumphoflife:BatsandMoths.’Watchtheclipandanswerthequestions.

a. Whatdomostbatsusetolocateapreysuchasamoth?

b. Howdoesthefrequencyofthesoundchangewhenabatapproa-chesamoth?

In order to react to changes in their environment. To stay alive.

Eyeshine.

Echolocation using sonar.

Their calling rate increases.

Questions

38

Questions

c. Whatcounterweaponhavemothsdevelopedagainstthesonarofbats?

d. Whatisthemoth’sreactionwhenitnoticesabat’ssonar?

e. Whatismentionedintheclipaboutbatshuntingabovewater?

f. Writedowntwoimperfectionsinthewaylong-earedbatshunt.

Ears that can detect the bats’ sonar.

First it swerves away, then it plummets, or drops down.

Hunting above water could be an adaption to the moths’ falling

move. When they fall in the water the moths are easy prey

for bats.

(1) The bats are not able to locate possible obstacles.

(2) When the moth does not move, the bat is not able to find it.

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39

g. Whatdolong-earedbatsusetheirsonarfor?

h. Somespeciesofmothshavetakendrasticmeasurestoavoidbats.Writethismeasuredown.

i. A quote from the clip: “This brings the war full circle.” Explainthis.

33.High-pitchedsoundstravellessfarthanlow-pitchedsounds.Usethisfacttoexplainwhyelephantsuseinfrasoundtocommunicate.

Mainly for locating the rough position of their prey and

locating obstacles in their flight path.

They changed from night animals to day animals.

Probably moths turned to the night to escape birds.

Now they changed to the daytime again to avoid bats.

Unfor-tunately they have to deal with the birds again.

Example of a good answer: A herd can be scattered over a large

area, with no eye contact and lots of trees and bushes in their

environment. High-pitched sounds would soon be lost in these

trees or over long distances.

Questions

40

Questions

34.Readthefollowingarticleaboutelephantcommunicationandanswerthequestions.

SOURCE 1

Big TalkersEarth’s largest land animals have a lot to say, even when they don’t seem to be making a sound.

Thirsty and hot, 12 elephants plod across the fried African landscape. The water hole is less than a mile away now, and everyone in the herd is looking forward to a good, long drink. Tired calves want to stop, but mothers and aunts nudge them along. The older animals make soft, soothing noises. “We’re almost there,” they seem to say. “Just keep walking.”

Suddenly everyone stops. Huge ears stretch out like satellite dishes. After a minute or two of what seems like silence, the animals turn and walk away from the water hole, fast. As they go, the adults huddle close to the calves.

So what happened? Why did the elephants change their course? They seemed to be listening to something. And whatever it was, they got the message to flee! Yet human ears heard nothing.

Elephants make plenty of sounds that humans can hear, such as barks, snorts, roars, and trumpet-like calls. Often a herd will use such sounds to talk with other elephants. But they weren’t in the air this time.

Second LanguageFor years, elephants puzzled observers with this type of behaviour. But now scientists have solved the mystery. They discovered that elephants have a “secret” language they use for communicating over long distan-ces.

This special talk is based on infrasound, sounds so low in pitch that humans can’t hear them. The sounds can travel for several miles, allo-wing the six-ton animals to keep in touch across grasslands and forests in Africa or Asia.

Translating infrasound helps scientists begin to understand elephant behaviour. For example, it turns out that the elephants heading to the water hole may have heard warning calls from another herd. Perhaps a lion was slurping water and looking hungry. The cat would be no match for an adult elephant, but it might kill a calf. No drink would be worth that risk, so the herd turned away.

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41

SOURCE 1

Long-Distance CallsElephants use infrasound to communicate many types of messages over long distances. Some of their talk helps hold families together. To under-stand how this works, you need to know a little about elephant families.

Females spend their lives with mothers, sisters, and children. They form tight-knit herds of 10 to 20 members. The oldest female elephant, the matriarch, takes charge. Males live with a herd until they are teenagers. Then they depart, living alone or joining with other males in a “bachelor herd.”

The members of a herd often scatter over large areas to seek food for their mighty appetites. (An adult elephant can eat 136 kilos of grass and plants in a single day!) Long-distance calls let elephants know where their relatives are. And when the matriarch says, “Come here!” the herd gathers within minutes.

Like curious kittens, elephant calves sometimes wander off and get into trouble. When that happens, they cry for help. Adults respond with in-frasound calls and other noises: “It’s okay. We’re coming to help you.”

Adult males and females often live far apart, so they use infrasound to find each other at mating time. Females mate only once every four years or so. When a female is ready, she makes a special series of calls. Males who hear the calls storm toward her. Sometimes two or more males bat-tle fiercely for a chance to court the female.

Hearing AidsElephants tune in to all this talk with their large, powerful ears. An African elephant’s ear can grow to be six feet long and four feet wide. (Asian elephants have much smaller ears.) When straining to hear some-thing, the animal turns toward the sound and opens its ears wide.

At the same time, the elephant may raise its trunk to sniff at the wind. Elephants have a keen sense of smell. Odours may help them figure out what they’re hearing.

Elephants may have yet another way of learning what’s going on around them. Although scientists haven’t proved it, some think elephants can actually feel infrasound as the sound waves travel through the ground.

Source: Winkler, P (September 2001). Big Talkers, National Geographic Explorer, p. 4-7.

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Questions

a. “Earth’slargestlandanimalshavealottosay,evenwhentheydon’tseemtobemakingasound.”Explainthissentence.

b. Whatkindofsoundsdotheelephantsmaketocommunicatewitheachotherwithintheherd?

c. Whatisthe‘secret’languagethatelephantsuse?

d. Translatingthissecretlanguagehelpsthescientistunderstandelephantbehaviour.Writedownanexamplegiveninthearticletoexplainthis.

e. Longdistancecommunicationhelpsholdelephantfamiliestogether.Givethreeexamplesthatprovethis.

Elephants produce infrasound. This is sound we cannot hear but

elephants can.

Infrasound, barks, snorts, roars, and trumpet-like calls.

Communication through infrasound.

For example, it turns out that the elephants heading to the water

hole may have heard warning calls from another herd. Perhaps a

lion was slurping water and looking hun-gry. The cat would be no

match for an adult elephant, but it might kill a calf.

No drink would be worth that risk, so the herd turned away.

The members of a herd often scatter over large areas to seek food for their mighty appetites. (An adult elephant can eat 136 kilos of grass and plants in a single day!) Long-distance calls let elep-hants know where their rela-tives are. And when the matriarch says, “Come here!” the herd gathers within minutes.

Like curious kittens, elephant calves sometimes wander off and get into trouble. When that happens, they cry for help. Adults respond with infrasound calls and other noises: “It’s okay. We’re coming to help you.”

Adult males and females often live far apart, so they use infrasound to find each other at mating time. Females mate only once every four years or so. When a female is ready, she makes a special series of calls. Males who hear the calls storm toward her. Sometimes two or more males battle fiercely for a chance to court the female.

Questions

43

f. Which three hearing aids does an elephant use to know where thesoundiscomingfrom?

g. Gotowww.ovdbricks.nl.LookunderBiology,chapter2,sources.Openthelink‘Thelostelephant’,andplaythegame.Doyouknowenoughaboutelephantsandtheirwaysofcommunication?

35.Smell,justlikehearing,isusedforcommunication.Whatissmellusedfor?

36.Justlikeinnature,domesticdogsanddomesticcatsleaveterritorialscentmarks.Thesemarkscontainthesameinformationastheterrito-rialmarksoftheircousinsinthewild.Whatcanbelearnedbysniffingaterritorialscentmark?

37.Younganimalsdonothaveaspecificscentinthefirstfewdaysoftheirlives.Forexampledeercalveshavethischaracteristic.Whyisthis?

Their big ears, their trunks and their feet.

Marking territories, fi nding a mate, fi nding food and fi nding

the way.

Who left the mark and whether the dog or cat is healthy.

Males can also smell if a female is ready to mate.

So predators can not fi nd the young.

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44

Questions

38.Theimageshowsananttrailintoahouse.Theantsfollowaperfectline.Explainwhatsuchatrailisusedforandhowtheantsknowwheretogo.

39.Birds, such as pigeons, also use their smell to find their way backhome.Explainthis.

Such a trail is used to find their way to and from their nests and

food sources. The ants leave scent marks that mark the trail.

Birds smell different kinds of things along the way, such as a town,

corn fields, lakes, and so on. Everything along the way has a

specific scent. These scents are used to find their way home.

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45

To make sure a species continues to exist.

An organism gets bigger and heavier.

Changes in the way an organism looks or the way it lives.

2.6 Growth and development

40.Whatisthereasonthatorganismsmustproduceoffspring?

41.a. Whatisgrowth?

b. Whatisdevelopment?

42.Writedowniftheprocessesbelowareexamplesofgrowthordevelop-ment.Putatick()intheappropriatebox.

Process Growth Development

Ayoungsparrowstartstogetfeathers.

Acaterpillarhastomoultbecauseitisgettingbigger.

Anewtlarvaundergoesmetamorphosis.

Apolarbearincreasesinweightforitshibernation.

Youhaveincreasedinbodylengthsinceyourbirth.

Insideaduckeggalittleducklingisformed.

Aboygrowsabeardwhenheisanadult.

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46

Questions

43.Whatismetamorphosis?

44.Answerthefollowingquestionsaboutfrogsandnewts.

a. Whatisthereasonthatfrogsandnewtslaytheireggsinwater?

b. Whichtwoorgansdoesatadpoleusetobreathe?

c. Writedowntwofunctionsofatadpole’stail.

d. Whatcouldbeareasonthattadpoleschangeenvironmentduringtheirmetamorphosis?Writedowntworeasons.

The development from larva to adult; the organism changes in the

way it looks and how it lives.

The outside of an amphibian egg is like jelly. It dehydrates when it

is laid on land.

Its gills and its skin.

For moving and for breathing.

(1) They change their way of breathing: from gills and skin to lungs and skin.

(2) They change their diet: from algae to insects.

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47

e. Whatisabigdifferencebetweenthelarvaeoffrogsandthelarvaeofnewts?

45.Watchtheclip‘Triumphoflife:TadpolesTransformation’.Youcanfindthecliponwww.ovdbricks.nl,Biology,chapter2,sources.Answerthequestions.

a. TadpolesoftheAmericantreefrogundergoatransformationwhenpredators,likedragonflynymphs,arepresent.Onepartofthetrans-formationhastodowithgrowth,anotherpartwithdevelopment.Writedownwhichhastodowithgrowthandwhichwithdevelop-ment.

b. What is the advantage the transformed tadpoles have over thenymphs?

46.Whydoinsectlarvaehavetomoult?

The larvae of newts do not undergo complete metamorpho-sis,

tadpoles do.

Growth: they grow bigger.

Development: they get red tails.

They are faster than the nymphs

Because their exoskeleton, or skin, does not grow with them.

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Questions

47.What isthemaindifferencebetweeninsectsthatundergocompletemetamorphosisandinsectsthatundergoincompletemetamorphosis?

48.Onpage…..youwillfindfourpicturesthatrepresentthefourstagesinthelifecycleofabutterfly.Cutthemoutandputthemintherightorder.Writebeloweachstagewhat

1 2

3 4

Complete metamorphosis means that the larvae do not

resemble the adults. With incomplete metamorphosis the larvae

al-ready look like the adults.

Caterpillar starts making pupa Inside the pupa the caterpillar changes

Butterfly emerges out of the pupa

A very long middle finger.

Questions

49

Summarising puzzle

Thedescriptionsbelowhaveblanks.Youhavetofillintheblankswitha

keywordfromthechapter.

Therearemanydifferentkindsofanimals.Youareanexampleofa_____

_______animal.Themostsimpleanimalsare

____________animals.Allanimalsshowthesevencharacteristicsoflife.

One of these characteristics is ____________. Animals can do this by

swimming,walkingorflying.Mostanimalswalkonfourlegs.Someanimals

walkontheirwholefoot.Theyarecalled____________.Mostcarnivores

are____________.Theirlegsarequitelongsotheycanrunfast._____

_______animalsor____________,likehorses,walkonthetipsoftheir

toes.Birdscanflyusingtheirwings.Wingshaveaspecialcurvedshape

calledan____________.Inordertokeeptheir____________feathers

intiptopcondition,birdsmustpreenthem.Fishswimbypushingwater

away with their ____________. Cartilaginous fish sink when they stop

swimming.Bonyfishhavea____________.Thisorganpreventsthemfrom

sinking.

Allanimalsmusteat.The____________ofcowsareequippedforgrinding

thecellsofplants.Animalsthatonlyeatplantmaterialarecalled______

______.Carnivoresusetheir____________toholdtheirprey.Thesharp,

jaggedmolarsofcarnivoresarecalled____________.Youeatplantsand

meat.Soyouarean____________.Inordertostayalive,animalsneed

____________torespire.Fishbreathethrough____________.Notonly

fishareabletobreatheunderwater.Someinsectslikethemayflynymph

complex

unicellular

movement

plantigrades

digitigrades

Hoofed unguligrades

aerofoil flight

tail fin

swim bladder

molars

canines

herbi-

carnassials

omnivore.

oxygen gills

vores

Questions

50

arealsoabletodoso.Insectsthatliveonlandbreathethrough______

______.The____________arelittleholesintheabdomenofaninsect.

Mammals,birds, reptilesandamphibiansuse____________ tobreathe.

Animalsareawareoftheirenvironment.Alotofanimalsdependonsight.

Sightisalsoyourmainsensingorgan.Catsandothernightanimalshavea

speciallayerintheireyes.Whenflashedtheylightupinagreenishshine.

Thisiscalled____________.Batshuntwiththeirears.Using_________

___theyknowwhereapreyislocated.Batsareabletohearultrasound.

Elephants canhear a very low-pitched sound, infrasound. Tomake sure

thataspeciescontinuestoexist,animalsproduce____________.Young

animalsundergo____________togetbigger,aswellas____________.

Tadpolesareyoung frogs.Theyundergo______________tobecomean

adultfrog.Theseveralstagesinthelifeofanorganismcanbedepictedin

a____________.Insectsalsochangealotwhilebecomingadults.When

fullygrown,the____________ofbutterfliesform____________.Inside

theychangeintobutterflies.Youngbutterfliesandnymphsofgrasshoppers

mustgothroughaseriesof____________.

tra-

cheae stigmata

lungs

eyeshine echoloca-

tion

offspring

growth development

metamorphosis

larvae

life cycle

pupae

moults