continuity of learning assignments the student has been · digital learning: achieve 3000...

Continuity of Learning Assignments

Grade: 9-12 Subject: Biology

April 27-28 April 29-30 May 1-4 May 5-6 May 7-8

Essential Activity Essential Activity Essential Activity Essential Activity Essential Activity

Digital Learning: Achieve 3000 Stemscopes The student has been assigned: Biogeochemical Cycles 16.1 The Water Cycle (Pages 1-2)

Digital Learning: Achieve 3000 Stemscopes The student has been assigned: Biogeochemical Cycles 16.2 The Carbon Cycle (Pages 2-3)

Digital Learning: Achieve 3000 Stemscopes The student has been assigned: Biogeochemical Cycles 16.3 The Oxygen Cycle (Pages 3-4)

Digital Learning: Achieve 3000 Stemscopes The student has been assigned: Biogeochemical Cycles 16.4 The Nitrogen Cycle (Pages 4-5)

Digital Learning: Achieve 3000 Stemscopes The student has been assigned: Biogeochemical Cycles 16.5 The Phosphorus Cycle (Pages 5-6)

Extension Extension Extension Extension Extension

Achieve 3000 Article: The Water Cops (Pages 7-9)

Achieve 3000 Article: The Show of a Lifetime (Pages 10-12)

Achieve 3000 Article: Cold as Ice (Pages 13-15)

Achieve 3000 Article: Worms on the Menu? (Pages 16-18)

Achieve 3000 Article: A New Way to Grow Food (Pages 19-21)

4/8/2020

1

Biogeochemical Cycles

16.1 The Water Cycle

16.2 The Carbon Cycle

16.3 The Oxygen Cycle

16.4 The Nitrogen Cycle

16.5 The Phosphorus Cycle

16.1The Water Cycle

Biogeochemical Cycles

• The cycles that move water, carbon, oxygen, nitrogen, and phosphorus through biotic (living) and abiotic (nonliving) parts of the ecosystem

Water Cycle

Movement of water

Water Cycle

Evaporation is movement of water from earth to air (water turns to gas)

Water Cycle

• Condensation is changing of water from vapor to liquid (clouds)

4/8/2020

2

Water Cycle

Precipitation is movement of water from air to earth

Water Cycle

• Transpiration- special evaporation that is the movement of water from plants (occurs through stomata)

Global Warming

Global Warming is the trend of increasing average temperatures around the world attributed to an increase in greenhouse gases.

Loss of Polar Ice Cap since 1979

16.2The Carbon Cycle

Carbon Cycle

Shows how carbon and oxygen move through the environment

4/8/2020

3

Carbon Cycle

• Photosynthesis- plants use carbon dioxide to form carbohydrates (glucose) and release oxygen into the air (occurs in chloroplast)

• Carbohydrates- different types of sugars made by plants

• Converting nonorganic carbon in carbon dioxide to organic carbon in carbohydrates is called carbon fixation.

Carbon Cycle

• Cellular Respiration- plants and animals use oxygen and glucose to make energy (ATP) and release carbon dioxide (occurs in mitochondria)

• Combustion is the burning of fuels that releases carbon dioxide into the atmosphere

Importance and Effects on Ecosystems

• Burning fossil fuels for energy releases carbon dioxide into the atmosphere

• Too much carbon in the atmosphere is believed to be a major contributing factor to global warming

• Carbon dioxide is called a greenhouse gas because it traps heat in the atmosphere

Greenhouse Gases

16.3The Oxygen Cycle

4/8/2020

4

Most of the earth’s oxygen is found in the

earth’s crust as metal

oxides, and it is not

usable in this form. 16.4The Nitrogen Cycle

Nitrogen Cycle

• Nitrogen gas is changed into usable forms that plants can use by special bacteria called nitrogen fixing bacteria that live on the roots of some plants called legumes.

• Animals get nitrogen in the form of proteins when they eat the plants or other animals

• A small amount is also changed by lightening

Nitrogen Cycle

The Nitrogen Cycle

• Nitrogen fixation- a process that converts nitrogen gas (N2) to ammonia (NH3)

• Lightning can also convert atmospheric nitrogen to ammonia.

The Nitrogen Cycle

• Nitrification is the process that converts ammonia to nitrates (NO3-)

and nitrites (NO2-)

• Nitrates and nitrite forms of nitrogen can be used by plants to make proteins.

• Animals eat the plants and the nitrogen is reused to make their proteins.

4/8/2020

5

The Nitrogen Cycle• When living things die, they are broken down by a group of organisms

called decomposers.

ex. Bacteria and fungi

• Some bacteria can change

nitrates in the soil back into

nitrogen gas in the process of

denitrification.

• This puts nitrogen back into the

atmosphere.

Nitrogen Fertilizers

• Man made nitrogen fertilizers can sometimes dissolve and enter bodies of water.

• Eutrophication is the depletion of oxygen in a body of water that leads to the death of aquatic organisms.

Burning of Fossil Fuels

• The burning of fossil fuels creates nitrogen oxide gases, which can have several negative consequences including destroying the ozone layer.

• The ozone layer protects Earth from the sun’s harmful UV radiation.

16.5The Phosphorus Cycle

Phosphorus Cycle

4/8/2020

6

The Phosphorus Cycle

• Phosphorus does NOT enter the atmosphere

• Phosphorus is transferred between rocks, soil, water and living organisms

• Most phosphorus is found in the form of phosphate (PO4)

• Animals obtain phosphorus by eating plants and other animals

4/8/2020 Achieve3000: Lesson

https://portal.achieve3000.com/kb/lesson/do_print?lid=16875&c=56&step=multiple&steps%5B%5D=11 1/3

Photo credit and all related images:AP Photo

Los Angeles Department of Waterand Power conservation team

member Alonzo Ballengar (right)catches a gardener using too muchwater in Los Angeles, a city where

water conservation laws are in place.

Printed by: AMY PatePrinted on: April 8, 2020

The Water Cops

Article

PART 1

LOS ANGELES, California. There's a new group of police officerspatrolling the neighborhoods of Los Angeles, California. They're called"water cops." These water police are on the lookout for careless gardenerswho are not complying with the city's strict water conservation laws. Theselaws are more important than ever because California is struggling with anextended drought.

A total of 15 police officers are on water duty. They prowl neighborhoodsand respond to thousands of tips. Officials estimate that in Los Angeles,landscaping accounts for as much as 70 percent of household water bills.Therefore, officers look for people who use sprinklers during the day, cleandriveways with water instead of a broom, or otherwise waste the preciouscommodity.

Water is precious everywhere, but particularly where there is a shortage, asin California. In June 2008, California Governor Arnold Schwarzeneggerdeclared a statewide drought. He cited two years of below-average rainfall,low snow-melt runoff, and shrinking reservoir levels.

Los Angeles is a particularly thirsty city because of its expanding population. Early residents got their water from the LosAngeles River, which could not provide enough water to supply the rapidly growing population. The city and surroundingarea owes its existence to vast quantities of water piped in from the Colorado River and other sources. Conservationhas always been important but is essential during a drought.

Conservation efforts are nothing new in Los Angeles. In the early 1990s, city officials unveiled a program called "droughtbusters." When this voluntary conservation program yielded only a 4 percent drop in water use, officials realized theyneeded to get tougher.

In the summer of 2008, just after Governor Schwarzenegger declared the drought, officials placed limitations on wateruse. Penalties were imposed on people who did not comply. Offenders can now be cited with warnings or hit with finesthat start at $100 for homeowners. These fines automatically appear on water bills. Through enforcement of water laws,the water conservation team aims to inform people about the importance of saving water.

"They're in fact educators …to the public," said H. David Nahai. He oversees the team of officers. The team's goal is tosee a 10 percent drop in water use.

Getting people to comply with water conservation rules is still difficult in Los Angeles. Many residents there feel it isimportant to have beautiful green lawns and flourishing gardens. Department of Water and Power officer AlonzoBallengar has seen a general reluctance to conserve water. Ballengar says that some of the people he accuses of waterwaste turn out to be hired gardeners. Their employers insist that the lawn needs to be watered each day. Ballenger alsocame across a case where a woman was draining and refilling her pool every three days for no apparent reason.

The Water Cops



Sometimes, residents try to help enforce the law. In one case, a resident reported four of his water-wasting neighbors inregular order every week. In another case, a group of dedicated conservationists appointed themselves citizen bustersand patrolled their own neighborhoods. They called the water police when they saw anything from broken sprinklers tomysterious puddles of water.

Ballengar says that no one is safe from inspection—not even Governor Schwarzenegger. On a recent afternoon,Ballengar drove into the gates of the community where Schwarzenegger lives. Ballengar stopped for a moment in frontof the governor's mansion. He peered through the iron gate, searching for any evidence of water waste in the garden.

"Nothing," he said, before driving on.

The Associated Press contributed to this story.

PART 2

Dig Deeper

Six years later, the water shortage has not lessened. In April 2015, Governor Jerry Brown ordered cities and townsacross California to reduce their water use. He did so while standing in the Sierra Nevada on bare, dry grass. About 2meters (6.5 ft.) of snow should have been covering the field.

California is not alone. Most nations in the deserts of northern Africa and in the Middle East have severe watershortages. These are some of the driest regions on Earth, but their populations require more and more water as citiesgrow. Water that could be used to grow food is piped instead to the growing cities, where it is needed in homes andfactories. Egypt, once a center of agriculture, imports 40 percent of its grain.

Water shortages are a serious problem. But the situation is not entirely hopeless. Conserving can solve a big part of theproblem. What is conservation? It is action taken to protect and preserve the natural world. To conserve water means touse less of it. An average American uses about 168 liters each day. This is higher than in most parts of the world. Notethat more than 8 of those liters are wasted by leaking toilets. This is 5 percent of the total amount used per day.

Think about what you already know about the water cycle. What happens when aquifers, lakes, and rivers are used upfaster than the water in them can be replaced naturally? Available fresh water from these water supplies decreases.Water supplies in many regions are being used up. This makes conservation an urgent issue.

People conserve water in three ways:

They use less water. Some cities conserve their supply of water simply by repairing leaks in underground pipes.They reuse water. Many cities reuse treated wastewater for landscaping.They recycle water, or use water again for the same purpose.

People can conserve water on farms, in industry, and at home. Farmers can conserve water by using drip irrigationinstead of spraying water. Most industries can use water at least twice before returning it to a river or lake. For example,water used to cool machines can be recycled back through the same system. People can change their plumbing andtheir habits. Repairing leaking pipes and dripping faucets can reduce water use greatly.

By 2025, there will be about 2.8 billion people without enough water. That's five times as many as there are now. Publicofficials and experts can help manage water use. They can enforce fair laws. For example, what happens when a riverflows from one state into another? What if it crosses a national border? In such a situation, people must agree to sharethe water rights.

Dictionary

commodity (noun) something that can be bought and sold



comply (verb) to obey

landscaping (noun) improved scenery as a result of gardening efforts such as planting trees or flowers

penalty (noun) a legal or official punishment, such as a fine or imprisonment for committing a crime or other offense

shortage (noun) a lack

water cycle (noun) the continuous movement of water on Earth, through its atmosphere, and in the living things on Earth



Photo credit and all related images:AP Photo/NASA

Astronomers witnessed a rare sight:the beginning of a star's death.


The Show of a Lifetime

Article

PART 1

PRINCETON, New Jersey. In an enormous stroke of luck, astronomers forthe first time witnessed the start of one of the universe's most fieryphenomena: a supernova, the explosive event that indicates the end of astar's life.

On January 9, 2008, astronomers were using an X-ray satellite to observea supernova that had already begun. Unexpectedly, another star in thesame galaxy started to explode. This explosion produced an outburst thatemitted light 100 billion times brighter than the sun. This was the case eventhough the star and the sun were the same diameter.

From all accounts, this supernova was quite a blast. It was so bright that itflooded the satellite's instrument. The supernova gave the instrument a picture equal to "pointing your digital camera atthe sun," said Alicia Soderberg. Soderberg is an astrophysics researcher and lead author of a report on the event. Thereport was published in this month's issue of the journal Nature.

"As much energy is released in one second by the death of a star as by all of the other stars you can see in the visibleuniverse," said astronomy professor Alex Filippenko.

The astronomers were barely able to contain their excitement. "A star exploded right before my eyes," Soderberg said.

Filippenko called it a "very special moment because this is the birth, in a sense, of the death of a star."

The astronomers were thanking their lucky stars as they found themselves at the right place at the right time. Accordingto Filippenko, less than 1 percent of the stars in the universe will die in this way, in a supernova. Instead, most stars getstronger and then slowly fade into "white dwarfs." These are small, dense stars that produce little energy.

Witnessing two supernovae in a row, as scientists did, is highly unlikely. The chances of two supernovae explosionsoccurring so near each other at the same time, Soderberg said, are maybe 1 in 10,000. The odds are even less likely ofdiscovering them at the right time and with the right type of telescope.

Scientists said that this new glimpse of a supernova seems to confirm decades-old theories on how stars explode anddie. That makes the findings "a cool thing," said astrophysicist Stan Woosley, "but not one that fundamentally changesastrophysics."

The special telescope took pictures of the dying star for about three hours before it exploded.

The Show of a Lifetime



According to Filippenko, the death of this star went through the typical stages. These included the core becomingheavier in successive nuclear reactions. They also included atomic particles being shot out into the universe by way ofan explosion. This star, like all others, spent the first phase of its life converting hydrogen into helium. Once all of thehydrogen had been used up, the helium then converted to oxygen and carbon, and then into heavier and heavierelements until it finally turned into iron. That's when the star's core became so heavy that it collapsed in on itself. Thiscaused the supernova to begin with a shockwave of particles piercing through the shell of the star.

Filippenko explained one way to think about how this shockwave works: Take a basketball and a tennis ball and getabout five feet above the ground. Then, he said, rest the tennis ball on top of the basketball for a moment beforedropping them together. The basketball will bounce low, with little energy, then stop. The tennis ball will bounce high intothe air, with a lot of energy. The basketball, said Filippenko, is the collapsing core. The tennis ball is the shockwave thatwas seen by astronomers.


PART 2

Dig Deeper

Stars last for very long periods. But they are not permanent. Like living organisms, stars go through cycles. They gothrough cycles of birth, maturity, and death. The life cycle of a star is also called a stellar life cycle. It differs dependingon the mass of the star. Higher-mass stars develop more quickly than lower-mass stars. Toward the end of their lifecycles, higher-mass stars also behave differently from lower-mass stars.

Stars form inside a cloud of gas and dust. It is called a nebula. Gravity pulls gas and dust closer together in someregions of a nebula. As the matter contracts, it forms a hot, dense sphere. If its center grows hot and dense enough,fusion will occur. Then, the sphere becomes a star.

When a star dies, its matter does not disappear. Some of it may form a nebula or move into an existing one. There, thematter may eventually become part of new stars. The diagram shows the stages that stars go through in their life cycles.Notice that the length of a cycle and the way a star changes depend on the mass of the star at its formation.

Credit: Houghton Mifflin Company

The main sequence is the stage in which stars produce energy through the fusion of hydrogen into helium. Lower-massstars use their fuel slowly. So, scientists believe that they can remain in the main-sequence stage for billions of years.Scientists believe that the Sun has been a main-sequence star for 4.6 billion years. It will remain one for about another 5billion years. What happens when a lower-mass star runs out of hydrogen? It expands into a giant star in which heliumfuses into carbon. Over time, a giant star sheds its outer layers. It becomes a white dwarf. A white dwarf is simply thedead core of a giant star. No fusion occurs in white dwarfs. But they remain hot for billions of years.



Stars more than eight times as big as our Sun spend much less time in the main-sequence stage. This is because theyuse their fuel rapidly. After millions of years, a higher-mass star expands. It becomes a supergiant star. This is what theastronomers in the news article on page 1 witnessed and described. In the core of a supergiant, fusion produces heavierand heavier elements. When an iron core forms, fusion stops. Gravity causes the core to collapse. Then, part of the corebounces outward. The star erupts in an explosion. The explosion is called a supernova.

Dictionary

convert (verb) to change the nature or form of something

galaxy (noun) a large system of stars

main sequence (noun) the stage in which stars produce energy through the fusion of hydrogen into helium

nebula (noun) a cloud of gas and dust in space; stars form in nebulae



Photo credit and all related images:AP Photo/Jim Mone

Some office buildings use blocks ofice like these to keep cool in the

summer.


Cold as Ice

Article

PART 1

NEW YORK, New York. In the midst of the summer of 2007, some NewYork City companies found a way to limit their air conditioning use. Theyused an energy-saving system that relies on blocks of ice to provide coldair to pump through their office buildings. This saves electricity and moneyat the same time.

The system uses electricity to freeze water in large silver tanks. Thefreezing process takes place at night. The ice in the tanks sends out coolair, which then gets piped throughout the buildings all day. The followingnight, the water is frozen again so that the buildings can repeat the cycle.

The idea of using water or ice to cool rooms is not new. It dates back tobefore the invention of the first air conditioner. In India, people used to coolhomes by hanging wet grass mats over windows. In the 1800s, a physicianin Florida blew air over buckets of ice to cool hospital rooms.

Today, ice cooling is becoming more popular for several reasons. For one thing, the ice system uses less electricity thanair conditioning. This saves companies money. In addition, it does not use electricity during the peak load, or the time ofday when electricity demand is at its greatest. Instead, it uses electricity at night. This helps reduce strain on the city'spower grid.

Since ice cooling uses less electricity, it produces less pollution-causing carbon dioxide. When the company CreditSuisse runs its ice system instead of its air conditioner, its workers know they are reducing pollution. It is as if they havetaken 223 cars off the streets or planted 1.9 million acres of trees to absorb carbon dioxide.

Companies like Credit Suisse have several options for saving energy. They can use ice storage as their sole coolingsystem. Or, they can combine it with traditional systems to help ease power demands during peak hours. Credit Suissehas a traditional air conditioning system, but engineers use the energy-saving system first.

Credit Suisse engineers say that the system is extremely efficient. In many ways, it is also more practical than airconditioning.

"When you make something mechanical [like an air conditioning system], it can break, but a big block of ice . . . isn'tgoing to do anything but melt," said Todd Coulard of Trane Energy Services. Trane built the Credit Suisse system.

Trane also developed ice-cooling systems for other company buildings. Some of these companies received incentivesfrom a government organization. Why? The organization wanted to improve the power grid and help businesses reducecosts. According to Coulard, companies also like the fact that they are helping the planet.

Cold as Ice



"The idea of not only saving money for large companies, but doing something that benefits the environment, is [goodany way you look at it]," Coulard said. "It's doing the right thing."

Just how much energy does ice cooling save over air conditioning? Ice storage at Credit Suisse saves enough energy topower about 200 homes.

Still, Coulard says that an ice-cooling system is not appropriate for every office. It is probably best for large companies.Why? A building needs to have enough space for the large tanks. It also has to have the money to set up the system.Credit Suisse spent more than three million dollars to redo its cooling system. The company spends a great deal ofmoney on air conditioning. Therefore, the cost of setting up the ice system was worthwhile. That might not be true for allcompanies.

William Beck of Credit Suisse says the system just made sense for his company.

"If you take the time to look, you can find [creative] ways to be energy efficient, [as well as] environmental andsustainable," said Beck.


PART 2

Dig Deeper

An expert on ice cooling said, "…a big block of ice…isn't going to do anything but melt." You know what happens whenyou put water in a freezer. The water freezes into a solid (ice). What happens when you place ice on a warm plate? Theice melts back into liquid water. What happens if you leave the plate of water in sunlight? The water becomes watervapor. Ice, water, and water vapor are all made of the same kind of molecule. It has 2 hydrogen atoms and 1 oxygenatom. So, why are water, ice, and water vapor different?

The state of matter is decided by how its particles are arranged. It is also decided by the motion of its particles. Ice,water, and water vapor are examples of different states of water. States of matter are the different forms in which mattercan exist. A substance can change from one state to another. However, the molecules in the substance do notchange. Instead, they are arranged in a different way. This is why each state of matter has its own characteristics.

A substance can exist as a solid, a liquid, or a gas. The state of a substance depends on two things. It depends on thespace between its particles. It also depends on the way the particles move. The spacing of particles in the differentstates of matter is shown below.


Solids, liquids and gases have specific attributes. Solids have definite shapes. Their shapes do not change. They havedefinite volumes. Their volumes can be measured. Liquids have definite volumes. But they do not have definiteshapes. A liquid takes the shape of the container it is in. Molecules in liquids can move on their own. As a result, liquidscan flow. Gases are substances with no definite shape. They have no definite volume. Gases have volumes that changeto match the volumes of their containers.



Dictionary

efficient (adjective) done with the least amount of waste or effort

incentive (noun) something that encourages or motivates somebody to do something

power grid (noun) the power plants and power lines that help move electricity from place to place

sustainable (adjective) able to keep going



Photo credit and all related images:AP Photo/Don Ryan

Idaho restaurant owner Dave Krickmakes rich compost soil by feedingkitchen waste to 200,000 worms.


Worms on the Menu?

Article

PART 1

BOISE, Idaho. At Dave Krick's restaurant in Boise, Idaho, humans are notthe only ones enjoying the food. Krick's eatery also serves another speciesof diners, namely worms, which work around the clock to turn kitchenwaste into compost. The effort is part of the eco-restaurateur's plan toeliminate garbage.

For over a year, Krick has been feeding some 100 pounds (about 45kilograms) of food waste a day to 200,000 Vermont red wiggler worms. Theworms live in a metal bin in the basement of his restaurant. The large 14-by-4-foot (4.3-by-1.2-meter) bin contains a metal screen. The worms nestleon the screen in a mixture of organic dirt and everything from leftovers tokitchen scraps. The worms consume and digest the food. Their solid waste—called "castings"—then mixes in with the dirt, creating nutrient-richcompost soil. Krick uses the soil to grow plants in his restaurant's outdoorplanters and the garden at his home. This worm composting is known asvermiculture. The process results in less waste for a business that wouldnormally leave behind a lot of it.

"One of our goals is to eliminate our garbage by 2012," said the environment-conscious Krick.

Before Krick decided to take up vermiculture, he catalogued his restaurant's garbage. He wanted to determine wherewaste could be reduced. He considered the mass quantity of food scraps that are not used or are left behind by diners.Krick decided that vermicomposting—the process of worms creating compost—would be a good place to begin. He thenset up a vermicomposting bin in his restaurant's basement.

"We wanted to do onsite composting because it takes very little energy," Krick explained. "But regular compostingsmells, because it's basically the chemical process of heating things up, and in a restaurant setting we knew that wasn'tgoing to work."

Worm composting is less likely than regular composting to produce an odor because the worms eat the rotting food.

Only one other U.S. restaurant—located in Hawaii—has taken up vermicomposting. That's possibly because mostrestaurants simply don't have the space to do it.

"Restaurants pay a lot of money for rent, and at the end of the day they want to just send it off and have the composterpick it up," said Colleen Oteri. Oteri is spokesperson for the Green Restaurant Association.

There's also the potential "Ewww!" factor. Customers might be disgusted by the thought of thousands of squirmingeaters nearby.

Worms on the Menu?



"I [expected] that," said Tracy Solomon. Solomon is coordinator of sustainability for the restaurant in Hawaii thatpractices vermicomposting. "Sometimes when I go feed the worms I get a lot of people staring at me, wondering whatI'm dumping in the bins," she said.

Still, Solomon keeps her worm bins in an outdoor seating area, right alongside dining tables. She has found that thewriggling composters are not as unappealing to customers as she had feared.

"People just think it sounds like an interesting step to take," Solomon said.

In Idaho, Krick's vermicomposting project has worked well. In fact, the restaurateur plans to purchase another bin. Heplans to double the number of worms he feeds. Krick hopes to eventually sell the compost at a local organic nursery.

But Krick isn't expecting to become wealthy from the project. The bin he uses set him back about $12,000. He opted tofill it with the more expensive organic soil. That way, the resultant compost would be completely organic. According toKrick, selling the compost will pay for only a portion of the startup expenses.

"For us, we know that we're not ever going to [recover] the investment. But to eliminate our garbage, we find those gainsare [a part of] our business, [so it's] a matter of priorities," Krick said.

As his worm herd increases, Krick also hopes to sell starter buckets for home vermicomposting. Krick imaginesenvironment-conscious customers taking home doggie bags from his restaurant to feed to worms that were cultivated inthe eatery's basement. If Solomon's experience in Hawaii is any indication, Krick's plan could go over extremely wellwith customers.

"Kids love it," said Solomon. "I do presentations for kids at schools, and we give starter bins of worms and castings tothe schools for their own gardening."


PART 2

Dig Deeper

Decomposers and scavengers play a critical role in the structure of food chains and food webs. When things die, theycan't grow anymore. But the building block chemicals they contain, like carbon and nitrogen, need to be recycled into thesoil so that they can be reused in food webs. That's where decomposers and scavengers come into the cycle.

Scavengers, such as turkey vultures, find dead animals to eat. In the process, they rip them into smaller pieces. Then,decomposers such as worms, fungi, and bacteria go to work. They each break down material differently, but they all playan important role in our environment. Without decomposers and scavengers, our world would be overrun with deadmaterial, and plants wouldn't get the essential nutrients they need to grow.

Dictionary

compost (noun) dead leaves, food, and other things that are added to soil to make it better

decomposer (noun) an organism that breaks down already dead organisms; it's last in a food chain

eliminate (verb) to get rid of

organic (adjective) produced by natural processes, without the use of chemicals or artificial substances

priority (noun) something that is placed first in importance

scavenger (noun) an organism that eats already dead organisms



sustainability (noun) the ability to preserve or maintain; the practice of trying to preserve natural resources for future generations



Photo credit and all related images:AP/Peter Dejong

Farming is starting to move indoors,where the sun never shines, rainfall

is irrelevant, and the climate isalways right. Indoor farming could

help solve the world's hungerproblem.


A New Way To Grow Food

Article

PART 1

DEN BOSCH, Netherlands. Picture a farm where the sun never shines,where rainfall doesn't matter, and where the climate is always right. It maybe hard to imagine. That's because most people think that crops must begrown outdoors. Research in the Netherlands suggests otherwise. Theperfect crop field could be inside a windowless building. It would havecarefully controlled light, temperature, humidity, air quality, and nutrition.Crops could be grown in a New York City skyscraper, a Siberian bunker, ora sprawling mall in the Saudi desert. Supporters say that these creativeindoor farms could be the answer to the world's food problems.

Hunger Around the World

Engineers need to find new ways to grow crops. That's because the worldis having trouble feeding itself. Of the 6.8 billion people who live on Earth,half of them live in cities. About 1 billion are hungry or malnourished.Hunger and malnutrition pose one of the greatest threats to healthworldwide.

The high cost of food is partly to blame for the problem. Food prices aresoaring due to the cost of energy required to plant, fertilize, harvest, and transport crops. Experts project that prices willbecome more unstable due to the effects of climate change. Scientists believe that climate change is being caused bycarbon dioxide in Earth's atmosphere. This gradual change in the planet's climate can interrupt farming practices. Forexample, long-term crop planning becomes difficult for farmers due to droughts, floods, and other unpredictableweather. Bad weather yields smaller crops. This causes prices to increase.

In addition, the world's population is growing. The United Nations (UN) predicts that by mid-century, the globalpopulation will grow from 6.8 billion to 9 billion. Feeding so many people may require expanding farmland. That usuallymeans cutting down forests and wilderness areas. People could also look for a way to increase crop yields.

"In order to keep a planet that's worth living on, we have to change our methods," said Gertjan Meeuws. Meeuws worksat PlantLab, a private research company.


Meeuws and three other Dutch bioengineers believe they've found one such method. They have taken the idea of agreenhouse one step further. They grow vegetables, herbs, and other plants in an enclosed and controlled environment.There is no natural light.

In the Dutch research station, strawberries, yellow peppers, basil, and banana plants take on an eerie pink glow underred and blue bulbs of Light-Emitting Diodes, or LEDs. While LED bulbs are expensive, the cost is steadily dropping. Thebulbs use far less energy than traditional light sources. The researchers also use about 90 percent less water than is




need for outdoor agriculture. The water in the research station trickles into pans as needed, and all extra water isrecycled. When light, water, and other natural elements are controlled, the plants use less energy to grow.

The Dutch researchers have been tinkering with their methods for more than a decade. They've experimented withcombinations of light, soil, and temperature on a variety of plants. Their experiments have paid off. The growth rate forcrops is three times faster than under traditional greenhouse conditions.

The researchers say they plan to build a commercial-sized building in the Netherlands by the end of 2011. The buildingwill be 14,000 square feet (1,300 square meters) and have four separate levels of vegetation. It will be ideal for what theresearchers call "vertical farming." After that, they imagine growing vegetables next to shopping malls, supermarkets, orother food stores. Meeuws says a building of 1,075 square feet (about 100 square meters) and 14 layers of plants couldprovide a daily diet of 7 ounces (about 200 grams) of fresh fruit and vegetables to the entire population of Den Bosch,about 140,000 people.

Indoor farming means producing crops near the consumer. This gets rid of the need to transport food long distances atgreat costs resulting from fuel use and food spoilage.

Researchers admit that people may need time to adjust to the idea of sunless, landless agriculture. Olaf van Kooten is aprofessor of science at Wageningen University. He has observed the Dutch project but has no stake in it. Van Kootensays that more research would be worthwhile.

"This system is a first clear step that has to grow," van Kooten said. "But it's clear to me a system like this is necessary."


PART 2

Dig Deeper

All plants share common characteristics. Scientists estimate that there are at least 260,000 different species of plantsthat live on Earth today. Plant species live in many kinds of environments. They have many different characteristics.

Plants are multicellular organisms.A plant cell has a nucleus. A cell wall surrounds the cell.Plants are producers, capturing energy from the Sun.Plant life cycles are divided into two stages. These stages are called generations.

Plant parts have specialized structures that help them to stay alive. You could say that a plant lives in two worlds. Theroots hold a plant in the ground. Stems and leaves are aboveground. They reach toward the Sun. Together, stems andleaves make up a shoot system. These two systems work together. They get a plant what it needs to stay alive.

A plant's root system can have as many roots as there are stems and leaves aboveground. Roots absorb water andnutrients from the soil. How do these materials get to the leaves? They travel through the stems. The leaves use thematerials along with carbon dioxide from the air. They make sugars and carbohydrates. The stems bring these energy-rich compounds back to the rest of the plant. Stems serve as a pathway. They transport water, nutrients, and energy-richcompounds. They move these materials from one part of a plant to another. In most plants, the materials move througha vascular system. This system is made up of long, tubelike cells. Vascular tissues are bundled together. They run fromthe roots to the leaves.




Two kinds of tissue carry out transport. Xylem (ZY-luhm) is one kind. It carries water and dissolved nutrients up from theroots. Phloem (FLOH-em) is the second kind. It transports energy-rich materials down from the leaves. Xylem cells andphloem cells are long and hollow, like pipes. The xylem cells are a little larger than the phloem cells. Both tissues havelong fibers. The fibers help support the plant's body. The tissues also have cells that can store extra carbohydrates forenergy.

Some plant structures have more than one critical function. For example, the plant's vascular system is found in itsstem. This allows the plant to transport materials between its leaves and roots. Long stiff fibers in the tissues of thevascular system support the plant. They give the plant its shape. But plant stems can also store the sugars made byphotosynthesis. Many plants change sugars into starch. They store energy-rich starch in their stems or roots. Broccoli,celery, and carrots all do this.

Dictionary

bioengineer (noun) A person who combines engineering and biology to aid human health.

consumer (noun) a person who buys something

humidity (noun) how much water is in the air

malnourished (adjective) not taking in enough food, or the right kinds of food, to keep the body well

producer (noun) an organism that captures energy from sunlight; it changes sunlight into chemical energy; this energy is stored inenergy-rich carbon compounds

sprawling (adjective) large; spread out

tissue (noun) a group of cells that are alike; they are organized to do a certain job

vascular system (noun) long tubelike tissues in plants; water and nutrients move through these tissues from one part of the plant toanother

continuity of learning assignments the student has been · digital learning: achieve 3000...

Documents