As you study the organization of a cell, you will learn about organelles and their functions. Each of these parts are vital to a cell's survival. For your Cell Persuasive writing assignment each of you will be asked to choose one organelle to portray. You will describe yourself (as an organelle) and try to convince the reader why you are the most important part of the cell.
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By Library of Congress, adapted by Newsela staff 12/22/2016 Question: Is a coconut a fruit? Or is it a nut? After all, the word "nut" is part of its name. Or is it a seed? Answer: A coconut is a fruit. It is a kind of fruit called a drupe. A drupe is a fruit with a hard pit. The pit is called a stone. Cherries, peaches and plums are drupes too. The coconut plant is a palm, not a tree. It does not have bark or branches. The Parts Of A Coconut: A coconut has three parts. The outside part is called the exocarp. It is smooth and green. The exocarp goes around the husk, or mesocarp. The mesocarp goes around a hard part called the endocarp. This is the stone. The coconuts you see at the supermarket are not like coconuts on palms. They do not have their exocarp and mesocarp. These are taken off before the coconuts get to the store. What you see is just the endocarp. The coconut's seed is inside the endocarp. Inside the seed is a “baby” plant. Food Is Inside The SeedThere are three holes on one end of a coconut. These are called pores. The new plant inside the coconut comes out from a pore as it grows. There is food inside the seed too. It helps the new plant grow. The food is called endosperm. It takes up most of the seed. It is the yummy white part we eat. The name coconut can be confusing because the word “nut” is part of it. A nut can be thought of as a fruit with one seed. Looked at that way, a coconut can also be a nut. However, a coconut is not a true nut, like an acorn. The coconut has pores that shoots poke through. That is how it releases its seed. A true nut does not do that. Instead, its seed is released in two ways. Either the nut is eaten by an animal, which then poos out the seed. Or, the nut falls apart over time and then the seeds are released. Interesting Coconut Facts
People use every bit of the coconut. They use it to make drinks and food. They use it to make beds and roofs. They even make instruments out of it. That is why the coconut palm is called the “Tree of Life.” Coconuts were not always called coconuts. They used to be called “nargil.” The word did not change until the 1700s. A coconut takes a year to grow fully. There are over 80 kinds of coconut palms. Coconuts grow as far north as Hawaii. They grow as far south as Madagascar. Respond to the below questions for the chance to earn extra credit! You will be entered into a raffle , the winners will be selected and posted on our blog page every Friday! 1. How many parts of a coconut are there? 2. Why do people have a hard time classifying a coconut? 3. What were coconuts called in the 1700s? 4. Which kingdom does a coconut belong to? 5. What is its cell type (Prokaryote/Eukaryote)? 6. What is the energy source of a coconut (Autotroph/Heterotroph)? 7. What is the cell number of a coconut (Unicellular/ Multicellular)? By Steven Zuryn, The Conversation, adapted by Newsela staff 11/01/2017 A look at the inside of a cell. The DNA within the nucleus (blue), mitochondria (green) and cellular skeleton (red) is clearly visible. Image from public domain/NIH.gov A cell is the basic unit of life. Cells have parts, called organelles. Each of the organelles has a different purpose. The mitochondria are an organelle. They are sometimes called the powerhouse of the cell. That is because they make energy for the cell. To learn more about mitochondria, we have to go pretty far back in time. In fact, we have to go back about 2 billion years. Where Did Mitochondria Come From? Your body is made up of trillions of cells. The earliest creature was just one cell. Then, one of the cells ate another. The big cell kept the small one inside it. Slowly, the two cells became one. The cell on the inside powered the bigger one. This is how creatures with more than one cell began. These inside parts are the mitochondria. There are hundreds or even thousands of them inside every one of your cells (except red blood cells). We cannot exist without them. They can't live without us either. Mitochondria are found in every plant and animal that has ever existed with more than one cell. Genes tell the cells what to do and how to work. A set of genes is called a genome. Our cells' genomes contain about 20,000 genes. Mitochondria have their own genome. It is very different from the genome of our cells. The genomes in our cells are called nuclear genomes. That is because they are located in a part of the cell called the nucleus. Unlike the nuclear genome, the mitochondrial genome is small. It has just 37 genes. It is shaped like a circle. The mitochondrial genome is passed down from the mother only. This is different from the nuclear genome. Half of the nuclear genome comes from your father. The other half is from your mother. What Do The Mitochondria Do? We need mitochondria in order to live. Mitochondria can also put our cells in danger, though. Cells make copies of themselves. That means the genome gets copied, too. Every time a genome copies itself, it can change a little. The mitochondrial genome makes copies much faster than the nuclear genome. This leads to more mistakes. What Happens When Something Goes Wrong?Changes in the mitochondrial genome can cause illness. These are called mitochondrial diseases. These diseases can appear at any age. There is no cure for these diseases. Scientists are looking for ways to treat them. They are also looking for ways to keep mothers from passing them along to their babies. Steven Zuryn is a professor at the University of Queensland, in Australia. Respond to the below questions for the chance to earn extra credit! You will be entered into a raffle , the winners will be selected and posted on our blog page every Friday!
1. What is a cell? 2. What are mitochondria? 3. What type of energy do mitochondria make ( in our class notes)? 4. What was the earliest "creature" ( 1st living thing)? 5. What is the term for an organism with many cells ( in our class notes)? 6. Where are mitochondria found? 7. What mistakes can a mitochondria cause? By Washington Post, adapted by Newsela staff 10/26/2016 Iridescent blue begonias show that plants can adapt to light levels with structural changes as well as chemical ones. Imagine a place where the oceans were full of purple algae and plants on the forest floor glowed a gorgeous blue. This is not the setting of a Dr. Seuss story or a science fiction book. This place was Earth. It may be assumed that plant life on our planet must be green. Plants make energy using a process called photosynthesis, capturing the sun's energy to make food. Photosynthesis requires structures called chloroplasts, which work to convert light to sugars for the plant's food. Chloroplasts are full of chlorophyll, a natural molecule. Chlorophyll is green. This hasn't always been the case, though. Studies have suggested that the earliest plants that used photosynthesis were a deep purple, because they relied on photosynthetic chemicals that absorbed different wavelengths of light. Plants Absorbing Light Not all the energy from the sun makes it to plants. Even when light shines on a plant, the plant doesn't use all of it. It actually uses only certain colors to make photosynthesis happen. Plants mostly absorb red and blue light wavelengths. When we see colors, it is actually a color that the object we are looking at does not absorb. In the case of green plants, they do not absorb light from the green range. These early plants did not absorb light from a purple range. A new paper in the journal Nature Plants describes how a shimmering blue plant can still exist. Begonia pavonina, or the "peacock begonia," dwells in the dim rain forests of southeast Asia. It has adapted to the low levels of sunlight there by developing leaves that are a bright azure. The unusual coloring comes from photosynthetic structures called iridoplasts, explained co-author Heather Whitney. She is an expert in plant surfaces at the University of Bristol in England. Like chloroplasts, these structures provide the cellular machinery for photosynthesis. They collect light and turn it into energy. For that light gathering, they also rely on chlorophyll, which absorbs red and blue light and reflects green (giving plants their typical appearance). Bending Light Makes Leaves Shimmer When Whitney and her partners examined B. pavonina cells, they noticed that the iridoplasts had a very strange shape. They were layered on top of one another, membrane upon membrane separated by a thin film of liquid. It's almost like a stack of pancakes held together with maple syrup. The effect is similar to what happens when you see oil on top of water in a puddle. "The light that is passing through gets slightly bent - it's called interference," Whitney said. It makes the leaves shimmer. This layering of iridoplasts causes the light that hits them to bend over and over again. This creates a shininess. More importantly, it enables the structure to absorb the types of light available on the dark floor beneath the forest canopy. It absorbs colors like red and green. Only blue light gets reflected back, so that's what humans see. Plants Adapt In Order To Survive Whitney and her partners also think the layering causes light to react more slowly with the photosynthetic chemicals in the structure. This allows even better light gathering to take place. To Whitney, the finding offers further evidence of plants' amazing versatility. Because they are unable to move when conditions are unfavorable, they must find other ways of adapting to the world around them. Often, they adapt chemically. For example, plants developed a purple photosynthetic chemical many years ago, as it was well suited to the kinds of light that were available at the time. "But plants aren't just factories," stuck using the same types of equipment for generation after generation, Whitney said. Iridoplasts show they can alter their machinery. They use those structural changes to work with the light that is available to them. "And who knows?" she added. "They've probably got loads of tricks we don't know about yet." They need those tricks to stay alive. Respond to the below questions for the chance to earn extra credit! You will be entered into a raffle , the winners will be selected and posted on our blog page every Friday!
1. Read the following statement and identify the term it relates to in our unit on nutrition. Plants make energy using a process called photosynthesis, capturing the sun's energy to make food. 2. What type of sugar does a plant produce during photosynthesis (in our class notes) 3. What is the chemical formula which represents glucose? 4. How have these plants adapted to their environment? 5. If the plants did not adapt to their environment what may have happened to the species? By Hannah Devlin, The Guardian, adapted by Newsela staff 04/27/2017 A keeper holds a naked mole rat while it's being transferred from a holding cage at the Knoxville Zoo on March 28, 2006, in Knoxville, Tennessee. Scientists now believe that the famously weird naked mole rat can survive without oxygen. AP Photo/Wade Payne Naked mole rats feel no pain. They do not get cancer and they look kind of like baggy sausages with teeth. The naked mole rat is a famously weird animal. Now scientists have discovered what could be the animal's strangest ability. Mole rats can live without oxygen for nearly 20 minutes. Without oxygen, a human would die within minutes. It Can Live Without Oxygen For A Period Of Time The mole rat can switch a process inside its body. This allows it to live without oxygen, said Thomas Park, a professor of biological sciences at the University of Illinois at Chicago. The mole rat has rearranged some parts of its metabolism. Metabolism is the chemical process that takes place in plants and animals to keep them alive. It is how the food we eat turns into fuel that keeps our bodies working. The process works differently in plants and animals, though. The naked mole rat's metabolism normally works like other animals. However, if there is not much oxygen, it switches. It is able to get fuel without oxygen, which is how the process works for plants. They Live In Stuffy, Crowded Burrows This ability probably came about over a long period of time. Mole rats live in stuffy, crowded burrows, where more than one hundred of them sleep together. Scientists knew that oxygen levels in the tunnels are low. The conditions would be unsurvivable for other animals. Until now, they did not know how naked mole rats manage. So, the team studied mole rats breathing air that had very low levels of oxygen in it. After five hours, the mole rats appeared to be unharmed. The mice that did this died within 10 minutes. There was not enough oxygen in the air to keep them alive. With no oxygen at all, the mole rats stayed alive. The mole rats were in a hibernation-like state. Humans Need Oxygen To Survive Some humans can train themselves not to breathe for more than 10 minutes. Sometimes, deep-water divers will do this. Most humans cannot be without oxygen for more than a few minutes. Grant McClelland is a biologist at McMaster University in Canada. He was not involved in the study, but thinks the findings are amazing. “I wouldn’t have predicted this ability for any mammal,” he said. As oxygen levels dropped, the mole rats stopped moving. Then, their eyes shut. Next, their heart and breathing slowed. And, there was a sudden spike in the levels of fructose in their blood. Switch To Fructose Helps Produce Energy Fructose and glucose are kinds of sugar. Animals use glucose to make energy, and plants use fructose. The team discovered that the mole rats did not burn glucose to produce energy when oxygen levels were low. Instead, they switched to fructose to make energy. Scientists never observed this in an animal before. “We were very surprised by this finding,” said Jane Reznick. She is Park’s co-author of the study and is based in Germany. This could be helpful to humans, the scientists said. Understanding how mole rats make this switch could lead to treatments for patients suffering from a lack of oxygen. This can happen during a heart attack or stroke. They Can Live More Than 30 Years Mole rats have fascinated scientists for a long time. They can live more than 30 years. They can easily run backwards and forward. They also eat their own poo and can move their teeth individually like chopsticks. Plus, they are one of the strangest looking creatures on the planet. Now, they have one more strange trait to add to this list. Respond to the below questions for the chance to earn extra credit! You will be entered into a raffle , the winners will be selected and posted on our blog page every Friday!
1. What is the naked mole rat's "strange" ability? 2. Humans need oxygen to live, what is the term for when oxygen is required for a life process ( in our class notes)? 3. What is metabolism? 4.What are the 8 life processes that combine together to accomplish metabolism( in our class notes)? 5. What are two types of sugar? 6. What is the chemical formula for glucose ( in our class notes)? 7. How can understanding why naked mole rats switch from oxygen required to no oxygen required be helpful for scientists to understand? By Washington Post, adapted by Newsela staff
The environment plays a role in the changing colors of leaves in autumn. Even as the leaves are dying, they are helping the trees prepare for winter. Photo from: Flickr.What is your favorite thing about fall? For many people, it is the changing leaves on the trees. In this season, the leaves change color. They turn from green to yellow, orange and red. Then the leaves change again. They turn brown. They get very dry. Finally, they fall to the ground. Then we can crunch them under our feet! Not all trees go through these changes. Only some have changing, falling leaves. Why do these leaves change color in the fall? Plants Need Sugar To GrowIn the spring and summer, leaves are green. This is because of chlorophyll. It sounds like CLORE-o-fill. It is a kind of pigment. A pigment gives something its color. Chlorophyll is a green pigment. It has a big job: It soaks up sunlight. Plants cannot eat the way people do. They make their own food. They do this through a process called photosynthesis. It is pronounced fo-toe-SYN-thuh-sis. Chlorophyl soaks up sunlight. The sunlight helps the plant turn air and water into sugar. That is the food plants need to grow. In fall, days get shorter. There is less sunlight. That means leaves cannot make as much sugar. Instead, they use sugar they saved up over the summer. So trees stop making chlorophyll. It would waste energy to make it. Before long, there is none left. All the green is gone. Red Leaves Live LongerThat explains where the green goes. Where do the new colors come from? Chlorophyll is not the only pigment in leaves. They have other pigments, too. They have the one that makes carrots orange. They also have the one that makes egg yolks yellow. Green steals the show for most of the year. After it is gone, the other colors show through. Then you see orange and yellow in leaves. Trees displaying their fall colors. In the fall season, the leaves change from green, to orange, red and yellow, and lastly to brown. Photo: Wikimedia Commons. Reds show up, too. They only show in the fall. Scientists are not sure why. Going from green to red takes a lot of sugar. That is energy trees should be saving up. One guess is that red protects dying leaves. This color blocks sun damage. It helps the leaves live longer. They can store more sugar for energy that way. So it may be worth it for the leaves to turn red. Not all trees turn the same colors. Some types of trees turn yellow. Others turn shades of yellow, orange and red. Crunchy Piles Of Brown LeavesFall begins with green leaves. They turn bright orange, yellow or red. But then they change again. Sunlight and frost kill off these pigments. Only one survives. It is called tannin. This pigment is brown. Next, the cells of the leaf break down. Leaves weaken and dry out. Wind shakes the branches. The dying leaves break away. Fall ends with crunchy piles of brown leaves. In spring, green will return. Trees will make new leaves. The color cycle will begin again. Respond to the below questions for the chance to earn extra credit! You will be entered into a raffle , the winners will be selected and posted on our blog page. 1. What do scientists believe leaves turn red? 2. What life characteristics is displayed when leaves change colors and eventually fall off? Explain. Newsela Article By Kevin Spear, Orlando Sentinel, adapted by Newsela staff 10/27/2017 Rachel Santulli works for Marine Turtle Research Group at Archie Carr National Wildlife Refuge in Brevard County, Florida. She monitors nighttime nesting of sea turtles, surveying hatching activity at daybreak. During an excavation, she found a live, baby green turtle. She released it and watched as it crawled into the Atlantic surf. Photo by: Kevin Spear/Orlando Sentinel/TNS. Beaches in Brevard County in Florida are a major refuge for sea turtles. Until last month, they were home to many nests. Then Hurricane Irma hit Florida. About half of all the green turtle nests were destroyed in the storm. Scientists called it a major blow to the threatened animals. But the big picture for green turtles looks much better. Scientist Kate Mansfield thinks Irma may just be a small setback. Mansfield works at the University of Central Florida, or UCF. She runs the school's Marine Turtle Research Group. In the 1980s, green turtles rarely appeared on Florida's Atlantic Ocean beaches. Over time, that changed. The number of green turtles grew larger and larger. It grew so large that it beat the number of loggerhead turtles this year.This trend is largely due to new laws. Some of the measures protect nests and eggs. Others help limit the use of bright lights that can disorient the turtles. Turtle Population Goes Down After HurricanesBut there's still one thing to worry about, Mansfield said. It's the number of damaging storms that continue to crash into Florida. "One year's storm is sad but not a big deal," said Simona Ceriani. She is a scientist with the Florida Fish and Wildlife Conservation Commission. "It's the frequency of storms that matters." Ceriani said green turtles were having great success before Irma. Unfortunately, the storm destroyed a lot of their progress. For more than 30 years, the UCF turtle group has been studying sea turtles. The scientists focus on the Archie Carr National Wildlife Refuge. This is a protected area. It stretches 20 miles along Brevard and Indian River counties. Many turtles give birth there. Their nesting makes up about one-third of all turtle nesting in the United States. This summer, the beach looked much different. Some parts of Archie Carr looked like they had been bombed. That's what happens when turtles plow up sand for thousands of nests. Mental Map Of The BeachUCF turtle scientists have made mental maps of the beach. They have learned how to read the jumble of holes and tracks. One of these scientists is Rachel Santulli. She said she is so familiar with the beach that she no longer uses her GPS to get around. Making sense of tracks and nests is best done in the evening, she said. That's because the sun is low and shadows are longer. It makes it easier to see turtle paths in the sand. For now, the sun was high in the sky. Santulli began digging through a nest where eggs had hatched.Her job was to record the number of empty shells. She also recorded the number of eggs that failed to hatch. There were nearly a dozen. Some were filled with a stinking liquid. Also deeply buried was a living, wiggling hatchling. Unlike its siblings, it wasn't able to tunnel out of the nest. "Nothing beats this," Santulli said as she carried the hatchling to the sea. "This is definitely one of the best parts." Comment one way you could help with this upsetting issue to be entered to receive extra credit. Get Creative! 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![]() A GENIUS! The Great American Eclipse: This is a stellar couple’s costume option. On August 21, a solar eclipse passed over the United States, from Oregon to South Carolina. It was, unquestionably, one of the biggest events of the summer. This costume will be reusable: Another solar eclipse will pass through North America in 2024. ![]() 2. Nikola Tesla Grab a suit, draw on a mustache and strike the classic pose. One of the pillars of electrochemical science, Tesla is a perfect costume for science lovers across the board. You can even pull the whole costume together by talking to birds and telling them you love them. ![]() 3. Ms. Frizzle and the Magic School Bus A blue dress and some cut-out stickers. Dress up as your favorite cartoon school teacher from the 90's. Leave a comment of a Science Costume Idea on this blog to be entered to receive extra credit! Winner will be announced on our blog feed!
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