Main->Readings->4th Grade "Stretches"
Here's all those weird, astounding, important, and useless facts I share in 4th grade science class. You can read them in order or click on the topics below.
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Seed Plants |
[Classifying Plants] [Roots, Stems, and Leaves] Making New Plants] [Photosynthesis] |
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Vertebrate Animals |
[Grouping Living Things] [Fish] [Amphibians] [Reptiles] [Birds] [Mammals] |
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The Digestive System |
[Cells to Systems] [Digestive System] [The Food Pyramid] [The Food Label] |
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Matter |
[Matter] [Measuring Matter] [Properties of Matter] [States of Matter] [Changes In Matter] |
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Work and |
[Straight Line Motion] [Collisions] [Gravity] [Putting Energy To Work] |
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Earth, Moon and Sun |
[Earth, Moon and Sun] [The Seasons] [Eclipses] [Tides] |
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Ecosystems |
[Living and Nonliving World] [Summer Vacation] |
Seed plants, which we're concentrating on this chapter, are called "spermatophytes." Ferns, mosses, liverworts and algae are all types of non-seed plants.
Nonflowering plants, on the other hand, are seed plants. They are known as gymnosperms, which means "naked seed." Flowering plants are known as angiosperms.
Classifying things means to sort them into groups by their traits.
In the 1700s, a young Swedish medical student named Carl (Carolus) Linnaeus (1707-1778) (along with a friend, who died) decided to classify and name all living things. He named over 8,000 species of plants and over 4,000 species of animals, giving each creature two names.
He didn't just name them things like "Hotfoot McGillicuddy" or "Sherlock Holmes," or "Mighty Rumpled." He had a system.
The system was a system of binomial nomenclature.
Uh, that means he gave everything two names.
Seriously, this was a very cool thing. They were Latin names he used, and the two names actually meant something, and named the organism's species and genus.
We still use his system today. The bean leafroller moth, for instance, has a Linnaean name of Urbanus proteus.
Every root has a mass of tiny hairs on it. These aren't hairs like the ones on our heads, which are dead. Root hairs are individual living cells. Without the root hairs, the plant won't survive.
Living things need nitrogen, and even though our air is mostly nitrogen we can't just grab it out of the air. It has to be combined in compounds. There are tiny little living things (bacteria) that live in the soil and on plant roots, and those bacteria take the nitrogen out of the soil and fix it into nitrogen compounds.
Unfortunately, if you harvest a plant to eat it, the nitrogen goes with it, so that's why you sometimes have to fertilize the soil with nitrogen. We call that fertilizer "plant food," but it isn't actually food. Plants make their own food using sun, water, and carbon dioxide.
If you plant a seed, no matter what position it's in--up, sideways, or upside down--the root always grows downward.
Soybeans are grown all over the world, partly because they come already equipped with a nitrogen-fixing bacterium in their roots.
The banyan tree sends shoots down from its branches which grow into roots in the ground and make new banyan trees.
Roots we eat include turnips and radishes.
The stem has a system of tubes in it which carry the water and food through the the plant. The set of tubes which carries water is called the xylem, and the set of tubes which carries food is called the phloem.
The liquid food carried by the phloem is called sap.
Humans like to collect sap for many different reasons.
In the woody stem of a tree, there are two parts to the xylem: the heartwood and the sapwood. Heartwood, in spite of its name (you'd think a heart would have to be alive), is dead - it's just called "heart" because it's the central part of the trunk. Sapwood is the outer, living layer. Every year a new layer of sapwood is added, which is why a tree trunk has rings.
Just to confuse things, if a stem grows horizontally (flat) below the ground, it isn't a root but a rhizome (like the rhizome of an iris). Fat underground stems are called tubers (like a potato). Other fat underground stems are called corms (like the corm of a gladiola).
Stems we eat include celery, asparagus, and rhubarb.
You can identify most plants just by looking at their leaves, which is good because that's the part of the plant that is still there when there aren't any flowers, fruits, nuts, or seeds.
If the leaf is just one blade, it's a simple leaf. If it has two or more leaflets, it's a compound leaf. If two leaves are attached exactly on opposite sides of the stem, they're opposite, and if three or more are attached the same way, they are whorled. Single leaves attached to the stem in alternating order are alternate.
The stuff that makes leaves green is called chlorophyll, and the tiny cells that have it in them are called chloroplasts. We'll learn more about chlorophyll later.
The stomates are usually open during the day and closed at night.
Chlorophyll has a very strong green color. Even though most leaves also have yellow and red colors (carotene, xanthophyll, and anthocyanins) in them, they're hidden until the fall when the chlorophyll drains out of the leaves. That's why the leaves "change color" in the autumn - actually, they don't change color so much as show their true colors!
When Dr. Turner was a kid, people raked leaves in the fall and burned them. Now leaf burning is illegal in many areas because of air pollution, health problems, and fire hazards, so people rake them into the street and leave them for pick-up, and the leaves get dumped in a municipal pile somewhere. Dr. Turner frankly doesn't understand why we don't just rake them into a nice pile in the back yard and let them go back into the soil instead. She'd leave them on the lawn if she could so the grass would die and she wouldn't have to mow it, but the neighbors would probably sue her.
Leaves we eat include lettuce and spinach. Not to mention watercress, cabbage, bok choy, and parsley.
When living things make more living things like them, that is called "reproduction." Flowering plants reproduce by pollination. Bacteria often reproduce by dividing in half, and so do protists. Fungi reproduce with spores. Most animals reproduce with sperm and eggs.
When people talk about the birds and the bees, they don't mean the stork brought you. This is what they mean: birds and bees (and wind, and moths, and occasionally gardeners) carry pollen from the stamen of a flower to the pistil of another flower (of the same kind) in a process called pollination. This fertilizes the flower, and causes the flower to form a fruit with seeds. One way or another, the seeds get to the ground and grow new plants, form flowers, and the process starts over again.
Well, maybe that's not what they mean when they say "birds and bees," but that's what the birds and the bees do to flowers.
Flowers we eat include broccoli, artichokes, and cauliflower.
Fruits we eat include squash, zucchini, and tomatoes. No kidding. Oh yeah, and apples, oranges, cherries, and pears too, but you knew that.
In 1983, the U.S. Supreme Court ruled that the tomato was a vegetable, not a fruit, for tax purposes. (don't believe me? check out http://www.csmonitor.com/durable/1998/02/05/home/home.3.html)
Here's the recipe for photosynthesis: Carbon Dioxide + Water + Chlorophyll and Sunlight = Sugar + Oxygen. This recipe is written by chemists as CO2 + H2O --> (CH2O) + O2. They don't mention the chlorophyll and the sunlight because chemical reactions just give the ingredients. The sunlight gives the energy for photosynthesis to happen and the chlorophyll stores the sunlight's energy. It's like not mentioning the oven in a recipe for baking cookies.
One formula for chlorophyll (there are different forms) is C55H72N4O5Mg. What that means is it has a heck of a lot of carbon and hydrogen atoms in it, and it's a very big molecule, as molecules go. That is to say, you still couldn't see it if you were the size of a mite on the body of a flea living on the elbow of an ant. Molecules are that small.
The word animal comes from the Latin word anima, which means "air," or "breath." What do you think is the reason for this name?
Most of the animals on Earth are insects. Insects are invertebrates (they don't have backbones).
Sharks are vertebrate animals, but they don't have bones. They have cartilage. They don't have scales, either. So there.
The fear of animals is called zoophobia.
Mammals have been on Earth about 200 million years.
Scientists who study fish are called ichthyologists. That's pronounced ick-thee-OL-o-jists.
Biologists know of 22,000 different species of fish. They only know about 21,500 species of amphibians, birds, reptiles, and mammals altogether. Why do you think there are so many?
There are about 50 species of fish that don't have eyes.
Fish don't have ears on the outside, but they can hear anyway. Fish without eyes can't see, however. Why do you think that's possible?
A single codfish may lay up to 3 million eggs. That's 3 million. Talk about your large families...
As you might expect, the fear of fish is called ichthyophobia.
Amphibians breathe through gills when they're young, and many of them breathe with small lungs when they're older. Most of them also breathe through their skin. What do you think it would be like to breathe through your skin?
Frogs and toads are carnivores. They eat meat.
What's the difference between a frog and a toad? Frogs (Ranidae) have smooth, moist skin and live near water. Toads (Bufonidae) have dry, warty-looking skin and are more likely to live on land. Touching a toad will not give you warts and kissing a frog won't give you a prince. Sorry.
The axolotl is a cool-looking salamander which never really loses its gills and stays in the "larval" (tadpole) stage all its life.
Frogs live anywhere in the world where there's fresh water except for Antarctica.
People who study reptiles are called herpetologists, a word which comes from the Greek herpeto, a creeping thing. They could be called "creepythingologists," but they aren't.
The iguana is a popular reptile pet. Unfortunately, though they're cute and small when you first buy them in the pet store, they grow to be five or six feet long and usually need lots of attention and custom-built cages. They are also not very intelligent. They cannot fetch, beg, sit, or catch a frisbee. They're good at playing dead, though. My daughter's iguana Percy lived in our kitchen in a huge tank we had built for him. His expression made eating breakfast an interesting experience, as if you were being watched by an extremely bored dragon. Iguanas, however, do not eat princesses or knights or even the occasional villager. They're herbivores, which means they eat plants. When Percy died, it took us a couple of days to realize it.
Snakes are not slimy. They are dry and cool. If you want slime, try an earthworm or better yet, a slug.
The fear of reptiles is called bactrachophobia.
The upper part of the turtle's shell is called the carapace, and the lower part is called the plastron.
The carapace of most turtles has about 50 bones in it.
The study of birds is called ornithology. Like astronomy (the study of stars), it's a science where ordinary people can still do a lot of the research. You don't have to be a scientist to watch birds or to discover a new species of bird.
The Gray Catbird mimics the songs of at least 44 other species of birds, as well as gray tree frogs and a variety of mechanical sounds. It's my favorite bird. I had a gray catbird in the spruce tree in back of my house this past spring and it sounded like he was having a party in there.
Do you know the phrase "as dead as a dodo?" The dodo was a real bird which died out in 1681. It was the first creature known to have become extinct because of man and other predators, and because of the destruction of its habitat.
The fear of chickens is called alektorophobia.
You are a mammal. So am I. So is Mr. Baroody. So is every human being on the planet. Mr. Baroody's dog Jane is a mammal, too, and so is my cat Calamine.
It is very difficult to tell a female spotted hyena from a male spotted hyena. Spotted hyenas have no difficulty telling each other apart, however. Hyenas are mammals.
The large flying fox (Pteropus vampyrus) is the world's largest bat, with a wingspan of up to six feet. Bats are mammals.
The nine-banded armadillo is the state mammal of Texas. It's about the size of a cat, has armor, eats insects, and looks like nothing on earth. Armadillos seem as if they ought to be imaginary, but they're mammals like you and me.
The state mammal of Pennsylvania is the white-tailed deer (Odocoileus virginianus).
The world's fastest mammal is, of course, the cheetah.
The fear of cats is called ailurophobia
One of my sources says the average adult is made up of 100 trillion cells (that's 100,000,000,000,000), though different people say different numbers. Let me know what you find out yourself! Cells, as you might guess, are teensy (or, as scientists say, microscopic).
Every living thing on Earth is made of cells. Well, except for viruses, which are made of stuff that comes from cells.
Some of the organ systems of the human body are the skeletal (bones), muscular (muscles), integumentary (skin), circulatory (blood), digestive (digestion), respiratory (breathing), endocrine (glands), excretory (eliminating wastes), nervous (nerves), and reproductive (producing young) systems.
Your body makes over 700 different enzymes. I have no idea what most of them do. You need every one of them.
Many people, including doctors, will tell you that you must drink 6 to 8 glasses of water a day. You don't have to, according to scientist Heinz Valtin, who decided in 2002 to find out whether this advice was true or not. You get some water from the foods you eat. Fruits and vegetables are 80-95% water. Meat has some water in it, and even dry bread and cheese are about a third water.
How did this wrong advice get treated as if it was true? There was a report in 1945 by the Food and Nutrition Board that said you needed 1 mL of water for every calorie of food you eat, and nobody bothered to read it carefully and find out that most of that water was already in the food.
If you eat a balanced diet, you don't need sports drinks, energy bars, or much in the way of extra vitamins. It's all there in the food you already eat. But don't tell anybody. Think of all the people who would go out of business if people didn't listen to commercials and buy glitzy supplements.
The Food and Drug Administration is the agency that regulates the labels. You see a lot of claims on packages ("Low Fat!" etc.) but the FDA only allows manufacturers to make claims that have scientific evidence. If it says "reduced fat," it has 25% less fat than the regular brand. "Light" means 50% less fat than the ordinary version of the product. Bet you didn't know those terms had a special meaning.
Just because something says it's low fat, that doesn't mean it's especially healthy. Pretzels, for instance, are low in fat, but they're basically just bread with a lot of salt on them.
Also, just because something advertises itself as a "fluid replacement drink" or "sports drink" like Gatorade or Powerade, that doesn't mean it has anything special in it, either. Gatorade has water, several different types of sugar (sucrose, glucose, and fructose), and small amounts of electrolytes (like salt) which your body loses when you sweat - salt and potassium.
Matter
You think matter is solid, huh? Hah! It's mostly empty space and energy. The smallest particles of matter are called atoms, and atoms are made out of subatomic particles. Subatomic particles are energy.
In fact, there is so much energy tied up in atoms that if you split a bunch of atoms, you get the explosion of a nuclear bomb. In fact, the Sun shines because it is releasing some of the energy of its atoms.
However, you can't split an atom by banging on it. If that were possible, you'd blow up the house every time you knocked on the door.
Heck, you can't even see or--really--imagine an atom, let alone split one by accident. Atoms are incredibly weird things. The only way to talk about them is with mathematics . . . but atoms do exist.
Scientists use scanning tunneling microscopes to make "pictures" of atoms - but those pictures are not made with light. Can you call them pictures at all?
Scientists prefer properties that can be measured. The science of weights and measures is called metrology.
Many measures are based on the human body. The inch comes from the width of a thumb. The foot (12 inches) is, of course, the length of a foot. This can be a problem if you're dealing with people of different sizes. Measures like this are also hard to multiply, divide, and convert.
The United States still uses many of these old measures ("English customary units"), even though much of the rest of the world has changed to the metric system.
The metric system was started by the French in the 1790's. It's great because it works by multiplying by 10 and is easy to convert. It's incredibly reasonable. Scientists use it all over the world. Americans still haven't changed over completely, probably because somebody else thought of it first.
The word for changing over to the metric system is metrication.
Don't ask Dr. Turner "how many inches is that?" when she tells you to measure something in centimeters. The best way to learn the metric system is to use it. A centimeter is about the width of your little finger, if that helps. At least it's the width of Dr. Turner's little finger.
Density is a property of matter, describing how heavy something is compared to its size. Hydrogen is the least dense element, and osmium is the most dense. Gold is nearly as dense as osmium. A suitcase full of gold would be too heavy for a human being to carry. Sorry about that.
Water has a density of 1 gram per cubic centimeter (if it is fresh water, under normal circumstances). So one cubic centimeter of water would weigh one gram. How much would 1000 cubic centimeters of water weigh?
The Planet Earth has a density of about 5 1/2 grams per cubic centimeter.
The Planet Saturn has a density of about 2/3 grams per cubic centimeter.
If you had enough water to put it in, would the Planet Saturn float or sink?
Steel can be a liquid - molten steel. Mercury is a metal that is liquid at room temperature.
Although water is a solid until 0 degrees Celsius and a liquid until it boils at 100 degrees Celsius, that isn't true for other kinds of matter. Nitrogen is liquid at minus196 degrees Celsius, but it's a gas at room temperature. In fact, it makes up 70% of the air (all gas) that we breathe.
Heat is energy (the energy of moving molecules). Cold is the absence of energy. Heat is something. Cold is nothing.
Absolute zero is the temperature at which atoms don't move at all, minus 273 degrees Celsius. We have come within a few billionths of a degree of absolute zero, but we haven't gotten all the way there. Some people don't think it's possible to get there at all.
Oxygen, which is normally a gas, can be a solid--but not until it is cooled to -219º C. Heck, to make oxygen liquid you have to cool it to -183 º C. So it would be tough to carry around solid oxygen unless you also carried around an enormous refrigerator to keep it cold.
Even worse, hydrogen, which is a gas at normal Earth temperatures, isn't a solid until -259º C (not that far from absolute zero), and just to make it a liquid you'd have to bring it down to -252º C, a measly 7 degrees warmer.
If you cause a chemical change that combines hydrogen and oxygen you get the chemical H2O, (otherwise known as dihydrogen monoxide).
H2O, or dihydrogen monoxide, melts at 0º C and boils at 100º C. That means it's a liquid at most Earth temperatures.
H2O is otherwise known as water.
Wait a minute.
You mean water, a liquid, is made of two gases?
Huh?
Yup, the chemical change that happened when you combined hydrogen and oxygen made new stuff with different traits.
(by the way, chemists use the Kelvin temperature scale (which adds 273 to the Celsius scale) when they're measuring extremely cold things. On the Kelvin scale, absolute zero is, you guessed it, 0ºK.)
Galileo Galilei was a remarkable person. He was an Italian, born in 1564 and died in 1642. He had a talent for getting into trouble with authority. He also used a telescope to discover that Jupiter had moons, figured out that objects all fall at the same speed, and eventually was sentenced by the Church to house arrest for agreeing with Copernicus that the Earth was not the center of the universe.
Isaac Newton came up with the laws of motion (though his first law was actually a re-statement of Galileo's law) and also the laws of gravity. Oh, yeah, and laws of optics (light). Oh, yeah, and the branch of mathematics called calculus. He was English and lived from 1642 (the year of Galileo's death) to 1727. Sometimes my students ask me if Newton was a real person. Yes, he was real.
According to the National Safety Council, 1 in 8 drivers will be involved in a collision this year. More than 41,000 people lose their lives each year in car crashes, and two million more have disabling injuries.
Air bags help in front-end collisions, but not in side impacts. They also do not replace seat belts. Also, children 12 and under (and even small adults) can be harmed by air bags. You should probably sit in a back seat instead of in the front. When I was a kid, "shotgun" next to the grown-up in front was a popular place, but it turns out to be more dangerous there too.
If you sit in the back seat, use your seat belt. Dr. Turner lost her two front teeth when she was a toddler, when her mother came to a stop at a traffic light and she fell to the floor of the car
There is a story that Isaac Newton, while hitting under a tree, was hit on the head by an apple and suddenly thought of the Universal Laws of Gravition. This probably is not true.
As I frequently say to my students, there is gravity in space. If there weren't any gravity, the universe would fall apart. There is also gravity on the Moon. The Moon may not have any air, but it has gravity. According to Newton, every object with mass in the universe attracts every other object, according to how much mass it has and how far apart they are.
Newton's Laws are wrong, according to modern physicists, because gravity is even weirder than he thought. It may involve bending space, for instance. But Newton's laws work well enough to land a probe on Jupiter or to calculate the path of a baseball.
Before Galileo, people thought that objects shot into the air followed a straight line until they "lost their impetus" and fell straight down to the ground. Galileo showed that if there was gravity, objects followed a curved path called a parabola instead, because there were two forces involved. One force, at the beginning, shot the object in a straight line at a constant speed. The other force, which acted all the way along, was gravity, which pulled the object downward at a constantly increasing speed.
How can the knowledge of projectiles be useful? Well, how about baseball? Or war (bullets, rockets, intercontinental ballistic missiles)? Or space travel? Or landing a piece of wadded paper in a trash basket?
The kind of work we're talking about here is what physicists call work. Not what your mother calls work. You can be doing a lot of work playing with a yo-yo, riding a motorcycle, or going on a rollercoaster, but she probably won't agree unless she's a physicist or an engineer.
Some people think there are six kinds of simple machine: 1) the inclined plane, 2) the wheel and axle, 3) the lever, 4) the pulley, 5) the wedge, and 6) the screw. I think the wedge is an inclined plane that gets shoved into things and the screw is an inclined plane wrapped around another inclined plane.
Some people think there are two kinds of simple machine. In fact, when you get right down to it, it's just one of those arguments you can't solve.
A spring isn't a simple machine, and neither is a rubber band. Neither is a TV. A nail is, though (do you know what kind?) and so is a yo-yo.
We always see the same side of the Moon. That isn't unusual for a moon; it's caused by the tidal effect, which is caused by gravity.
The same amount of the Moon (half of it) is always lighted by the Sun, but we see different amounts of the light depending on where the Moon is. If the Moon is on the opposite side of the Earth from the Sun, it looks as if it's all lighted (full moon). If it is on the same side of the Earth as the Sun, all we see is the unlit part, so we can't see it at all (new moon). If it's off to either side, we see half the lit side and half the unlit side. And so on . . . we'll go over this in class. And over and over and over it.
The Sun is about 150 million kilometers from the Earth. The Moon is only about 380 thousand kilometers away. That's why they look like they're the same size, even though the Sun is immense and the Moon is pretty small. Things that are far away look smaller, and things that are near look bigger.
Let me put it this way. If the Sun were 80 centimeters in diameter, the Earth would be 8 millimeters in diameter, and the Moon is smaller than that.
If you forgot, a millimeter is one-thousandth of a meter, and a centimeter is one-hundredth of a meter.
Pluto is the ninth planet again, after being the eighth planet for quite a while. So the order of the planets from the Sun out is now Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto.
If you can call Pluto a planet. It revolves in a very off-kilter way, and it's really too small to be a planet.
It's too late to change, though. We called it a planet when we discovered it, so I guess it's going to stay a planet.
Of course, that means that when it's summer here, it's winter in the Southern Hemisphere.
The seasons have NOTHING to do with how far the Earth is from the Sun. NOT A THING. NO. Get that idea OUT OF YOUR MIND NOW.
As a matter of fact, when it's winter in the Northern Hemisphere, the Earth is slightly closer to the Sun than usual. So DISTANCE has NOTHING to do with it. Right? You got that?
The seasons are caused by Earth's tilted axis and by the direct and indirect rays of the Sun.
Let me repeat, the seasons are caused by the tilt of Earth's axis and by the direct and indirect way the rays of the Sun's light hit the Earth.
NO. STOP IT.
Oh, for heaven's sake.
By the way, the Sun doesn't give off "direct" or "indirect" rays. It's the curve of the Earth that makes rays hit directly or indirectly.
There can be as many as three lunar eclipses in one year. Yes, that's right, only three.
The phases of the Moon are NOT caused by eclipses. The Moon's orbit around the Earth is tilted so that even when the Sun, Earth, and Moon are in a straight line the Moon is still usually clear of the Earth's shadow.
There can be two to four solar eclipses in a year, but the chances of seeing one are much smaller. That's because the Moon's shadow is smaller and doesn't cover the entire Earth, only part of it.
The next total solar eclipse will be June 21, 2001, and will be visible from north of the Falklands, to the point of greatest eclipse in the south Atlantic west of Africa, to the Indian Ocean south-east of Madascar. It is visible as a partial eclipse as far north as the mid-Sahara. In other words, you aren't going to see it.
You shouldn't look directly at the Sun during a solar eclipse. That's not because of any mysterious eclipse effect. It's because you should never look directly at the Sun.
The word eclipse comes from a Greek word meaning "abandonment."
Okay, so an eclipse happens when the Moon is at one of the two nodes where the Moon's orbit crosses the plane of the ecliptic; and the period which determines this is the Draconic Month. However, the Moon also has to be aligned with the Earth and the Sun, that is, at a New Moon (producing a solar eclipse) or Full Moon (for a lunar eclipse); and the period governing this is the Synodic Month.
Whatever you say, Dr. T.
When the Sun and the Moon are lined up (at the new and full Moon), the tides are higher than usual because the Sun's gravity adds its pull.
At the time of the quarter phases of the Moon (when the Moon looks like a half), the tides are lower than usual because the Sun's force is at right angles to the Moon's force. These low tides are called neap tides.
The "tidal effect" just means that gravity pulls harder the closer you are to it.
No matter what sailors say, tides don't go in or out. They just go up or down. It's the slope of the land that makes the water seem to move towards or away from the shore.
Tides affect all the Earth's water, including oceans, seas, lakes, and ponds. It's just easier to see their effect on the ocean.
The only reason the water is pulled farther than the ground is that the ground doesn't change shape easily. The Moon's gravity pulls on the ground too, but the ground doesn't stretch much.
The whole Earth can be considered an ecosystem. So can a forest, an ocean, a swamp, or a pond.
Every part of an ecosystem affects many other parts. You can't change one thing and keep everything else the same.
An organism is any single living thing.
Organisms that use photosynthesis are called producers because they produce (make) food.
Organisms that eat other living things are consumers.
A decomposer is an organism that gets energy by breaking down dead plant or animal parts.
One of the problems we have today is that human beings are changing Earth's ecosystem just by living in it.
Scientists who study ecosystems are called ecologists.
If you want to sound really scientific, producers are known to ecologists as autotrophs and consumers are known as heterotrophs. Use those words at the dinner table to describe your food ("My, isn't this autotroph salad tasty, and in addition this very attractive baked heterotroph is downright delicious, heavens to Betsy!") and watch your parents' eyes glaze over. Don't blame me. I'll deny it.
Often when an unusually destructive hurricane hits, that hurricane's name is retired and never used again. Since 1954, forty names have been retired. (from http://kids.mtpe.hq.nasa.gov/archive/hurricane/names.html, 6/15/99)
Tigers have striped skin, not just striped fur.
No matter its size or thickness, no piece of paper can be folded in half more than 7 times.
It's impossible to sneeze with your eyes open.
When you blush, your stomach lining also reddens. (the previous four facts from http://www.madscience.org, 6/15/99)
This page last modified November 1, 2002