原版英语RAZ 教案(Z1) The Amazing Undersea Food Web_DS.pdf

《原版英语RAZ 教案(Z1) The Amazing Undersea Food Web_DS.pdf》由会员分享，可在线阅读，更多相关《原版英语RAZ 教案(Z1) The Amazing Undersea Food Web_DS.pdf（14页珍藏版）》请在淘文阁 - 分享文档赚钱的网站上搜索。

1、The Amazing Undersea Food WebA Reading AZ Level Z1 Leveled BookWord Count:1,785Visit www.readinga- for thousands of books and materials.WritingImagine being an oceanographer exploring the twilight zone.Write a journal entry about your findings,including details from the book.ScienceChoose one of the

2、 four ocean zones.Research to learn more about this zone and write a paper sharing your findings.Connectionswww.readinga-The Amazing Undersea Food WebXZ1Z2Written by Penny Atcheson and Elizabeth FoxLEVELED BOOK Z1The Amazing Undersea Food Webwww.readinga-How are animals from the four ocean zones con

3、nected by the undersea food web?Focus QuestionWritten by Penny Atchesonand Elizabeth Fox24euphotic zone(n.)the top ocean zone,which contains almost all of the oceans life(p.10)faults(n.)cracks in Earths crust along which movement occurs(p.20)photosynthesis(n.)the process by which chlorophyll in plan

4、t cells transforms sunlight,water,air,and nutrients into food(p.6)phytoplankton(n.)single-celled algae that live in a body of water(p.5)snorkeling(n.)the act of swimming using a short,curved tube that extends above the waters surface and allows the swimmer to breathe while under water(p.13)submersib

5、les(n.)small vessels that can operate underwater,especially at deep levels(p.21)trenches(n.)cracks in the seafloor;long ditches(p.9)zooplankton(n.)microscopic animals that live in a body of water(p.8)2423Glossaryabyssal zone(n.)the part of the aphotic zone that includes the deep ocean floor(p.19)acc

6、umulation(n.)a piling up of material over time(p.12)anemones(n.)plantlike,marine animals whose tentacles often look like flower petals(p.12)aphotic zone(n.)the bottom ocean zone,which receives no sunlight(p.19)bioluminescence(n.)the light or the emission of light created by a biochemical process wit

7、hin a living thing(p.19)chlorophyll(n.)a substance in plant cells that transforms water,air,sunlight and nutrients into food(p.6)disphotic zone(n.)the middle ocean zone,which receives very little sunlight and contains no plants and few animals(p.15)The Amazing Undersea Food Web Level Z1The Amazing U

8、ndersea Food WebLevel Z1 Leveled Book Learning AZWritten by Penny Atchesonand Elizabeth FoxIllustrated by Cende HillAll rights reserved.www.readinga-Photo Credits:Front cover:Corel,Inc.;title page,page 10:Photodisc/Getty Images;pages 3,14(both):ArtToday;pages 4,15:Minden Pictures/SuperStock;page 5:c

9、ourtesy of Prof.Gordon T.Taylor,Stony Brook University/NSF Polar Programs/NOAA;page 7:courtesy of Jacques Descloitres,MODIS Rapid Response Team,NASA/GSFC;page 11:Marty Snyderman/Corbis;page 12:courtesy of Mike White/Florida Keys National Marine Sanctuary/NOAA;page 13:courtesy of Florida Fish and Wil

10、dlife Conservation Commission;page 17:John Anderson/D;pages 18,20(both):courtesy of OAR/National Undersea Research Program/NOAA;page 21:courtesy of OAR/National Undersea Research Program,Woods Hole Oceanographic Institute/NOAA;Page 22:Chittima Kasa/Dabyssal zoneaccumulationanemoneaphotic zonebiolumi

11、nescencechlorophylldisphotic zoneeuphotic zonefaultsphotosynthesisphytoplanktonsnorkelingsubmersiblestrencheszooplanktonWords to KnowCorrelationLEVEL Z1WXN/A60Fountas&PinnellReading RecoveryDRA233Table of ContentsLet Me Introduce Myself .4The Food Web .8Life in the Sunlit Zone .10The Twilight Zone.1

12、5The Midnight Zone.19Back on Top .22Glossary .23 The Amazing Undersea Food Web Level Z122Back on TopSo you see,even though phytoplankton are only at the top of the ocean,were at the center of the food web,supporting all other life in the sea.Whether you enjoy the ocean for the beauty of coral reefs,

13、the mystery of the abyssal zone,or some tasty fish and chips,you have us phytoplankton to thank.4Let Me Introduce MyselfThe ocean,where I live,is an enormous buffet table for everything in it and for many land animals,including humans.When you think of the ocean food web,you might think of fierce gr

14、eat white sharks devouring their prey,or enormous blue whales gulping tons of krill.Or you might think of giant stands of seaweed being devoured by everyone,like an underwater salad bar.But did you know that more than 90 percent of all sea creatures end up being eaten by other sea creatures?That mea

15、ns that almost every organism in the ocean ends up getting eaten by another sea creature at some point or other.And almost every sea creature eats other sea creatures.The blue whale is the largest animal on Earth.21Animals living in this zone have taken advantage of the warmth and nutrients.Special

16、kinds of bacteria can use these nutrients in the same way that phytoplankton use sunlight.Tube worms,shrimp,and giant clams can all be found feeding on these bacteria around the openings,or chimneys.These chimneys were only recently discovered.Only a few submersibles,or submarines,have been built st

17、rong enough to withstand the enormous pressure at the bottom of a trench.This submersible can withstand the enormous pressure of an ocean trench.The Amazing Undersea Food Web Level Z15But there are little organisms that almost always get eaten but do not actually eat anything themselves.They are the

18、 most microscopic species in the ocean,yet they form the center of the oceans food web.Some people might think its a raw deal to be food for everybody else,but I find it to be quite a powerful job.Let me back up and introduce myself properly.Phytoplankton(FY-tow-plank-ton)is my name.Im an algae,whic

19、h is almost like a very tiny plant.But unlike plants,I have no roots,so Im not attached to the ground or sea floor.Im free to float around with the ocean currents.I prefer to remain near the surface of the sea,since Im quite fond of sunlight,and I can be found in every ocean on Earth.These microscop

20、ic phytoplankton are called diatoms.The Amazing Undersea Food Web Level Z120Ocean trenches occur along faults where large plates of the Earths crust come together.The colliding plates create canyons and cracks of up to 10,000 meters(32,808 ft)deep.You would think that nothing could survive at the bo

21、ttom of a trench in the darkness,cold,and pressure.But openings at the bottom of the trenches spew hot water and minerals from deep within the Earth.(Left)This chimney,called a black smoker,spews hot minerals.The warmth and nutrients support crabs(below),tube worms,and other animals.6Like plants,I m

22、ake food through a process called photosynthesis,rather than eating it.I use chlorophyll to capture the Suns energy and use it to convert minerals and nutrients from seawater into food.Just as in plants,chlorophyll makes me green.But Im so tiny that you can only see the color when there are billions

23、 upon billions of us in one place.Chlorophyll in plant cells converts sunlight and nutrients into food.SUNLIGHTNUTRIENTS FROM WATERCELLCHLOROPHYLL19The Midnight ZoneThis totally dark region of the ocean contains 90 percent of the oceans water,but almost none of its life.It extends from 1,000 to 5,00

24、0 meters(3,28016,404 ft)and below.The pressure is so great that it can crush almost anything,including most submarines,and the temperature is near freezing.But there is some life in the midnight zone,or aphotic(ay-FOE-tic)zone,if you look closely.Many of the tiny animals that live here,such as the l

25、antern fish,have little lights running up and down their bodies.The light comes from a special process called bioluminescence.This is the same process that produces light in fireflies.Jellyfish,squid,fish,and even bacteria are bioluminescent in this zone,where there is no sunlight.These lights make

26、it possible for animals to see and communicate with each other.These lights also help them find mates or food,and they also make them incredibly beautiful.Some oceanographers divide the midnight zone into two additional zones:the abyssal zone and ocean trenches.The abyssal zone is totally dark,and i

27、t covers much of the ocean floor,including vast plains,mountains,valleys,and canyons.The Amazing Undersea Food Web Level Z17Fortunately,there are billions upon billions of us.Thousands of phytoplankton can be found in one cup of seawater.All that photosynthesis going on helps provide the Earths atmo

28、sphere with well over half of its oxygen.We are also a good indicator of the oceans health.Scientists can see large patches of phytoplankton from space.They can get information about the levels of pollution in the water when they see us struggling or dying off.But in my opinion,our most important jo

29、b is providing the center of the food web for the entire ocean.We feed all ocean life forms directly or indirectly,from the smallest creature to the largest.A phytoplankton and zooplankton bloom shows up as light streaks in this photo taken from space.The Amazing Undersea Food Web Level Z118Tiny bio

30、luminescent animals glow beautifully in the pitch-black depths.8The Food WebHeres how it works:think about a simple tuna fish sandwich.Tuna are relatively large fish,and they eat smaller fish called mackerel.To make 1 kilogram(2.2 lbs)of tuna flesh,the tuna had to eat about 10 kilograms(22 lbs)of ma

31、ckerel.Those 10 kilograms of mackerel had to eat 100 kilograms(220 lbs)of an even smaller fish called herring.And those 100 kilograms of herring devoured a full 1,000 kilograms(2,200 lbs)of zooplankton.Zooplankton are microscopic animals.They include tiny animals such as krill,which look like little

32、 shrimp,and the larvae and babies of crabs,jellyfish,shrimp,and other fish.To support those 1,000 kilograms of zooplankton,10,000 kilograms(22,000 lbs)of phytoplankton were eaten.Tuna eat mackerel,which eat herring.Herring eat zooplankton,which eat phytoplankton.17Many animals in this zone depend on

33、 a diet of what scientists call“marine snow,”which is a nice name for dead phytoplankton and zooplankton!When we die,our bodies drift slowly down through the ocean layers like snow falling through the air.So even where we dont live,phytoplankton are eaten.Octopuses live in both the euphotic and disp

34、hotic zones.The Amazing Undersea Food Web Level Z19To give you an idea of just how much life I support,Ill take you through the ocean from the surface,where I live,down to the deepest trenches on the ocean floor.DisphoticZoneAphoticZone2,000 mOcean TrenchAbyssalZoneEuphotic Zone1,000 m5,000 m200 m3,

35、000 m4,000 m0 mThis cross section shows the different zones of the ocean.The Amazing Undersea Food Web Level Z116The famous giant squid also lives in this zone.Until fairly recently,no giant squid had ever been seen alive.The squids bodies occasionally washed up on shore or were found in the stomach

36、s of sperm whales.Though a few people have seen it at the surface,and a few scientists have seen it in the disphotic zone,the giant squid still remains a mystery.Sperm whales have sucker scars from fighting with giant squid.10Life in the Sunlit ZoneThe euphotic(yoo-FOE-tic)zone,or sunlit zone,is the

37、 top level of the ocean.It extends about 200 meters(660 ft)down from the surface.Theres lots of sunlight here,so we phytoplankton,along with ocean plants,love it.Consequently,most of the animal species in the ocean can also be found here.Red and green algae,also known as seaweed,cover much of the sh

38、allow ocean floor in the euphotic zone.Enormous giant kelp grow in thick forests,almost like forests on land,and provide shelter for many sea animals.Sea urchins live in the protected waters at the base of the kelp,and sea otters feed on those urchins.Sea otters also wind long strands of kelp around

39、 their bodies while they sleep in order to keep from drifting away.Otters feed and live in the sunlit zone.15The Twilight ZoneAs you go below the euphotic zone,the water begins to get darker,colder,and heavier.You are now entering the twilight zone.It begins at about 200 meters(656 ft)and goes to a

40、depth of about 1,000 meters(3,280 ft).The pressure in this zone would crush a person,but the life forms that live here have adapted to the pressure.The twilight zone,also called the disphotic(dis-FOE-tic)zone,doesnt have enough light to support photosynthesis and plant life,but some animals do make

41、their homes here.Others,such as whales,visit from the euphotic zone.Permanent residents include octopuses,squid,and strange-looking fish such as the hatchet fish and the viperfish.Many fish that live in this zone often have huge mouths with big,curved teeth.Because it is so hard to see,the fish dont

42、 hunt.Rather,they simply hold open their fearsome mouths,waiting for something to swim in.Many of them are black or dark red to blend in with the dark water.This angler fish is small but scary.The Amazing Undersea Food Web Level Z111Almost all the seafood humans eat comes from the euphotic zone.Clam

43、s,mussels,and oysters live on shallow ocean floors.Lobsters and crabs scuttle about in coral reefs and among seaweed beds.Most species of fish,including salmon,tuna,mackerel,cod,and swordfish,stay up in the sunlight where there is plenty to eat and good light for hunting.Though there are squid and o

44、ctopuses in the deeper zones,most of the ones that humans eat come from the euphotic zone.Most familiar fish,such as this hammerhead shark,live in the euphotic zone.The Amazing Undersea Food Web Level Z114One nondestructive way to sample ocean life in the euphotic zone is to look into a tide pool.A

45、tide pool is a small pool of water that remains when the tide goes out.You can find mussels,sea stars,urchins,clams,barnacles,and snails.You might even see an octopus,or you may spot a hermit crab scurrying about in another animals shell.You dont even have to get wet to see all the life that depends

46、,directly or indirectly,on me and my fellow phytoplankton.If you visit a tide pool,you may get a glimpse of a spiny sea urchin.13Humans love snorkeling and diving in the euphotic zone,especially around coral reefs.And they take thousands of tons of fish,both for food and for pets in tropical aquariu

47、ms,from these surface waters.Unfortunately,all this human activity,along with pollution,threatens the well-being of coral reefs and other areas in the euphotic zone.Coral polyps are often killed by pollution,boat engines breaking them,or divers stepping on them,and once the corals die,all the other

48、reef life suffers as well.Entire populations of fish can drop dangerously low from overfishing.Boats,anchors,and divers can break coral.The Amazing Undersea Food Web Level Z112The euphotic zone is also home to coral reefs,which hold most of the oceans plant and animal species.These fragile and beaut

49、iful areas are formed by the accumulation of the skeletons of small animals called coral polyps.They are found in clear,tropical waters where there is lots of sunlight.Sea fans,brain coral,clown fish,angelfish,lion fish,moray eels,sharks,shellfish,crabs,and lobsters all make the coral reef a colorfu

50、l and busy place.Anemonesanimals that look like beautiful flowering plantscatch zooplankton with their stinging tentacles.Jellyfish swarm in massive numbers,attracting the sea turtles that love to eat them.Coral reefs also provide a safe haven for the young of many creatures that will live in the op