Chapter 1

Biology: Leaves, Seeds, Nests, and Groups

NATURE

The world around us is full of so many living things that we are always trying to better understand. Scientists go out in the world and watch to see how plants grow, where animals make their homes, what insects eat, and more so they can learn more about the natural world. In the following experiments, you will be going for walks in your neighborhood and backyard to observe and learn.

TRY THIS

LEAF HUNT

Whether it's fall, winter, spring, or summer, there are usually leaves — blowing about in the wind, crunching under your feet, adding colors to a gray sidewalk. They grow on broad, towering elms and oaks and on tiny, wispy Japanese maples. What do these leaves do? Why are they attached to trees? What happens when the leaves fall and why do they change color? How do trees grow new leaves? All these questions can be answered by looking more closely at leaves and the trees to which they belong.

QUESTION

What kinds of leaves are in your neighborhood?

WHAT YOU NEED

Shoes

Bag

Magnifying Glass

Paper

Crayons

Why did the leaf go to see the doctor?

It was feeling green!

WHAT TO DO

1. Put on your shoes. You're going on a nature hike!
2. Look all around you as you walk. Pick up leaves you see on the ground and put them in your bag. When you think you have enough different leaves, head back home.
3. Lay out your leaves on a table. Sort them into piles by their shape. How many of each kind of leaf do you have?
4. Use your magnifying glass to look at the leaves up close. What do you see?
5. Put a piece of paper on top of your favorite leaf. Carefully rub a crayon over the area of the paper that covers the leaf. What do you notice about your picture?

WHAT'S HAPPENING

A tree is made up of a main trunk, branches that grow from the trunk, leaves that grow from the branches, and a root system underground that helps keep the tree upright and healthy.

Different trees have differently shaped leaves. Some leaves are pointy, some are round. Trees that lose their leaves in the fall are called deciduous trees. They grow new leaves in the spring. These leaves soak in sunlight and turn it into energy for the tree. The leaf stems carry food from the leaves to the trunk and the rest of the tree. Deciduous trees include elms, oaks, maples, and others. Trees that do not lose their leaves are called coniferous — their “leaves” are pine needles. Pines, firs, and spruces are coniferous trees.

WORDS to KNOW

deciduous: trees that shed their leaves in fall and grow new ones in spring.

coniferous: evergreen trees and shrubs that have needles instead of leaves.

FUN FACT

Seed Snacks

Did you know that seeds can be great snacks? Pumpkins, squash, sunflowers, and sesame plants all have seeds that taste yummy, especially when you toast them in the oven. You can mix them with raisins and chocolate for a perfect trail mix.

YOUR NOTES

You can save your leaves for a later experiment. Or you can use them to make natural “stained glass.” Press your leaves between the pages of a book. After a couple days, when the leaves are flat and dry, arrange them on a sheet of wax paper. Place another piece of wax paper on top. Ask a grownup to run an iron over the papers. Wait until the sheets are cool. Then use some string to hang your “stained glass” leaf artwork in the window!

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SUPER PINE CONES

Forests, parks, and neighborhood streets are full of old and young trees. How did the young trees begin? Trees make seeds that grow into saplings. The saplings then grow into trees. Some seeds are fruit — such as apples or cherries. Other seeds are nuts, such as acorns and chestnuts.

But seeds face many dangers. Animals like to eat fruit and nuts. And high winds and heavy rain can make seeds go bad or fall off the tree too soon. So trees have evolved clever ways to keep their seeds safe from hungry animals and bad weather so that the seeds can eventually find good soil and grow. For example, chestnuts have husks around them that break open when the chestnut fruit is ripe and falls from the tree.

FUN FACT

Super Cones

The Sugar pine tree produces the longest cones in the world. Some cones can be up to 2 feet long!

QUESTION

How do pine trees protect their seeds from bad weather?

WHAT YOU NEED

Dry pinecones

Large bowl

Water

Paper towel

Hair dryer

WHAT TO DO

1. Find some pinecones outside or at the store.
2. Put the cones in a bowl. Cover them with water.
3. Now watch! What happens to the pinecones?
4. Take the cones out and put them on a paper towel to dry.
5. Use a hair dryer to help the cones dry faster. What happens?

WHAT'S HAPPENING

A pine tree hides its seeds in cones — a shell that can expand and contract with water. When the cone gets wet, the shell shrinks, keeping the inner seeds nice and dry. Then when the cone dries, the shell expands, opening up to let the wind blow the seeds away so they can grow somewhere else.

Some scientists believe that pinecones can play a role in forecasting the weather. This is because cones open and close depending on the humidity in the air. If a cone is open, the air must be dry so the upcoming weather could stay dry. But if a cone is closed, then there's already moisture in the air and the upcoming weather could bring rain. Look at some pinecones near where you live. Are they open or closed? What is the weather outside? Are the pinecones accurate in their forecast?

FUN FACT

Johnny Appleseed

There once was a man who planted apple trees all over the Midwest in the late 1700s. His nickname was Johnny Appleseed, but his real name was John Chapman. He was born on September 26, 1774.

Cool Quotes

We must believe that we are gifted for something, and that this thing, at whatever cost, must be attained.

— Marie Curie

WORD to KNOW

seed: a grain or fruit that enables a plant to reproduce itself.

YOUR NOTES

Draw a picture of your pinecones, first when they're dry and then when they're wet.

Bubbles and Butter

Almost every day we eat something that a teeny tiny organism helps to make. To learn something about this little critter, solve the Falling Letter puzzle below. Figure out where to put the letters in each column. The letters all fit in the boxes under their own column, but not always in the same order! The black boxes are the spaces between words.

Whirly Seeds

Certain trees have seeds with a unique shape. They are designed to be caught by the wind and twirl away!

To make your own whirly seed, use a ruler to connect each number pair with a straight solid line.

Then, connect each letter pair with a straight dotted line.

Cut around the edge of the pattern to remove the puzzle from the page.

To complete the Whirly Seed, cut on the solid lines, and fold as directed on the dotted lines.

Drop your paper seed from a (safe) high place!

NOTE: If you don't want to cut up the book, make a copy of this page first.

SCIENCE LAB: SOCKS, SEEDS, AND APPLES

If too many seeds grow in the same place, the new plants have to compete for resources, such as sunlight and water and nutrients in the soil. So it's a good thing for seeds to travel to new locations where it's not so crowded. That way, the seeds can find the perfect soil in which to grow and thrive.

QUESTION

How do seeds travel?

WHAT YOU NEED

Old socks (they're going to get dirty, so don't pick new ones)

Sunny day

Cellophane tape

Piece of paper

Apple

Knife

Adult

WHAT TO DO

1. Put on your socks and go out to your backyard.
2. Now go back inside and take off your socks. What do you see?
3. Use the cellophane tape to take off any seeds from your socks.
4. Place the tape on a piece of paper so you can look at the seeds. Do you recognize any of them?
5. Now ask an adult to cut open an apple lengthwise. What do you see inside?

WHAT'S HAPPENING

Seeds travel many different ways. Sometimes plants get help from animals such as squirrels, who bury nuts in all kinds of places, and light breezes that blow dandelion seeds into the air.

How do you know if a tree is a dogwood?

By its bark!

Flowers make seeds, too, in the form of pollen. And bees help make new flowers by carrying pollen from one blossom to the next. When a bee lands on a flower, it drinks some nectar. The bee will later turn the nectar into honey. But first, the bee picks up some pollen powder on its legs. When the bee visits another flower, it leaves some of the powder behind. This powder helps the second flower make its own pollen, which results in more flowers. Flowers need bees and bees need flowers.

Fruit trees hide their seeds inside tasty treats. Apple seeds grow into trees that make flowers that turn into fruit. When animals eat the fruits, they also eat the seeds. So the seeds travel inside the animals and pass into the soil through the animals' droppings. Be careful not to step in any droppings outside!

YOUR NOTES

Try going out in your socks at different times of the day and during different times of the year. Do you find new seeds on your socks?

Try cutting open other fruits. Which ones have seeds?

Criss-Cross

Some biologists experiment with combining plants or animals with different characteristics to get new plants or animals that are better. Break the First to Last, Letter Shift, and Vowel Scramble codes to see if you think this silly scientist was successful with his crazy experiment!

Ecosystems

Our world is a collection of all kinds of ecosystems. An ecosystem is a community of animals, plants, trees, insects, their habitats, and the climate in which they live. Everyone in these communities shares food and natural resources. Ecosystems can be as big as the whole world and as tiny as a rock.

A tree is a great example of an ecosystem. It provides a habitat for squirrels, birds, and insects. It provides shade for plants on the ground. It drinks in sunlight to grow bigger and make seeds that the squirrels and birds eat and scatter around. Birds also eat the insects. And when the tree dies, it becomes a part of the ground again, helping the new trees grow big and strong.

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FRIENDLY NEIGHBORS

Because members of a community share resources and rely on each other, it's important to know your neighbors. That way, you can all work together to solve problems and look out for each other in hard times.

QUESTION

Who lives in your community?

WHAT YOU NEED

Pencil

Paper

Shoes

WORD to KNOW

community: a group that interacts and lives in a common area.

ecosystem: a community of living things.

FUN FACT

Going Buggy!

Insects are the largest animal group on earth. There may be as many as 750,000 different insect species!

WHAT TO DO

1. Put on your shoes — you're going on a neighbor walk!
2. Who do you see in your neighborhood? Write down the animals, bugs, and people you see. These are the members of your community.
3. Count how many you see of the same kind of neighbor. What did you find out?

WHAT'S HAPPENING

Think about how your life impacts the lives of your neighbors, both animal and human. If the resources in an ecosystem are harmed, if the water becomes polluted, or an animal species is removed, the whole ecosystem is hurt. It's important to see ourselves as part of a larger web of life. What we do matters in so many ways.

YOUR NOTES

Now that you know who is in your community, think about what resources all of you share. Do you share city utilities like water and electricity? Do you share food and weather? How can we take better care of our community?

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HOME SWEET HOME

What does your home look like? Is it big or small? Is it made of wood or bricks? Who lives in your house? Living things live in all kinds of homes, made of all kinds of materials. Sometimes these houses are high up in a tree, or underwater in a lake, or deep underground in the soil. Where would you build your house if you could live anywhere in the natural world?

QUESTION

Where do the members of your community live?

WHAT YOU NEED

Shoes

Pencil

Paper

WHAT TO DO

1. Go for a walk around your backyard. Keep a lookout for any kind of creature — bug, bird, or animal.
2. Where are the birds flying to? Where are the bugs crawling or flying to? Where do people go at the end of the day? Write these places down on your paper.
3. Now head home and look at your list. Do any places have more than one resident? Do birds and squirrels live in the same places? Do spiders and people live in the same places? Can you add more details to your list to give these roommates their own homes?

WHAT'S HAPPENING

Ecosystems are made up of habitats — places where the members of the community live. These places may be natural, like trees and holes in the ground, or man-made, like houses. Natural habitats keep birds, animals, and/or insects safe and dry. And they also provide safe places for animal mothers to have babies and raise them.

Hidden Habitat

Look closely at this kid's messy habitat. Can you find the mushroom, mouse, spider, snake, lizard, owl, crow, sunflower, dragonfly, and snail?

WORD to KNOW

habitat: the place where a plant or an animal usually lives and gets what it needs to live.

Ecosystems are also referred to as biomes. The major biomes are deserts, grasslands, tundra, forests, and freshwater and saltwater environments. These environments consist of specific animals and plants, and climates that are specific to each biome.

YOUR NOTES

Draw a picture of the habitat you found with the most inhabitants.

SCIENCE LAB: WHAT'S FOR DINNER?

All living things in an ecosystem are called organisms, and organisms are connected by food chains. Organisms need energy to live, and each living thing gets its energy from another part of the food chain.

Producers are the first link in the chain because they produce, or make, the resources used by other members of the food chain. Plants are producers. They turn sunlight into sugar and oxygen that other living things use for energy. Consumers consume, or eat, producers. Certain animals, called herbivores, eat plants to get energy. Other animals, called carnivores, eat herbivores. They get energy from eating other animals. When producers and consumers die, the last link in the food chain takes over. That link is the decomposers. They break down the animals and plants so that they can nourish the next generation.

QUESTION

What parts of your food chain do you eat?

Where are you on the food chain?

WHAT YOU NEED

Paper

Pencil

Fridge

WHAT TO DO

1. Using paper and pencil, make a list of everything you ate in your last meal. If you can't remember, open your fridge and take a look at its contents.
2. Draw a square around the foods that came from plants. These could be lettuce, spinach, or fresh herbs like rosemary or basil. Fruits and vegetables like tomatoes, cucumbers, pumpkins, strawberries, and peppers all come from plants.
3. Draw a circle around foods that came from animals. These could be sausage, ham, beef, pork, chicken, cheese, or eggs.
4. Draw a triangle around all the liquids, like milk and juice.
5. Draw a star around all the solids.
6. Take a look at your list. What do you see? Do any foods have multiple shapes around them?

WHAT'S HAPPENING

Humans are omnivores, which means we eat plants and animals. And we are at the top of the food chain. If we pollute the waters, litter the land, or consume too much, we harm the delicate balance in the food chain.

Food chains often overlap. Animals will eat different kinds of food to survive, and sometimes that food is a part of a separate food chain. If you draw lines between the organisms in multiple food chains according to who eats whom, you create a food web. Food webs are often complex, and they show how animals and plants are affected by changes in their habitats. The rainforests hold more than half of all the animal and plant species in the world. So there are millions of food chains in the rainforest biome.

WORD to KNOW

herbivore: animal that eats only plants.

carnivore: animal that eats other animals.

YOUR NOTES

Even though humans are omnivores, some of us eat more plants or more animals. What do you like to eat? Are you more of an herbivore or more of a carnivore?

Who in your family is a producer? Who is a consumer?

What is a plumber's favorite vegetable?

A leek!

Diamond Poem

A diamante is a type of poem shaped like a diamond. It is used to combine thoughts about two different elements, such as a bird and a fish. To create a diamante about ecosystems, use the words around the edge of the page to fill in the pattern.

Food Chain

A food chain goes from small to big — the most simple plants and animals are used as food by the next bigger organism. Unscramble the words at the bottom of the puzzle. Can you put together two different food chains?

Classification

Scientists have found that certain kinds of animals share the same traits — the same kind of food, the same habitat, the same call. The more traits these animals have in common, the more likely they are to share the same classification.

Big groupings, with lots of animals and plants in them, are called kingdoms. The two main kingdoms are the animal kingdom and the plant kingdom. As scientists start finding fewer things in common, these kingdoms get smaller and become groups. The two main groups in the animal kingdom are vertebrates — animals that have a spine — and invertebrates — animals that don't have a spine. The main groups in the plant kingdom are flowering plants and nonflowering plants. These divisions help scientists better understand our natural world.

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BIG, SMALL, NESTS FOR ALL

Have you ever looked up into a tree and seen a bird's nest? It's an amazing feat of construction, built with simple materials using only a beak. They sometimes use things like twigs, leaves, and grass, and even string, bits of cloth, or strands of hair.

QUESTION

How do birds build little nests and big nests?

WHAT YOU NEED

For the little nest:

Small twigs from outside

Glue

String

Cotton balls

Leaves from earlier experiment

For the big nest:

Blankets

Pillows

Sheets

WHAT TO DO

Little Nest

1. With the help of a grownup, place sticks in a circle, gluing the overlapping ends together.
2. Add another layer of sticks and glue. You can insert bits of string, cotton, and leaves to soften the nest.
3. Keep adding layers until you have a cup-shaped nest.
4. If you like, you can place your nest in a low tree and watch to see if any birds adopt it.

FUN FACT

Home Beak Home

Birds are born knowing how to make the right nest for their species. But they do need to practice. Birds get better at building nests the more they build them!

FUN FACT

Nest Names

Did you know nests have names? A badger's nest is called a sett. A wasps' nest is called a vespiary. A hare's nest is called a hide. And an eagle's nest is called an eyrie.

Big Nest

1. Lay one blanket on the floor. This is the base of your nest.
2. Take a second blanket and roll it up on the floor. Fold the roll into a triangle and place it on top of the first blanket.
3. Take another blanket and do the same thing. But when you place it on top of the second blanket, turn it to the right a little bit so that the points don't line up.
4. Do the same with two or three more blankets or sheets.
5. Now grab a couple pillows and get in. Ready for bed?

WHAT'S HAPPENING

Birds' nests are a common kind of habitat in an ecosystem.

Birds make nests to lay eggs in and to raise their young. Some build their nests in trees; others build them on the ground or even in water. Eagles put their nests on rocky ledges. There are birds that don't make nests at all. They use other birds' nests. A father Emperor penguin nestles his egg up against his warm body to keep the egg safe and dry. There are insects and animals that make nests, too. Wasps construct them high up in attics and trees and other sheltered spots. And squirrels make nests, as do some fish, reptiles, termites, and others. Each species wants to protect its babies so they will grow and continue the species.

YOUR NOTES

Was it easy to build these nests with your hands? Try building the large nest with only your feet. Can you imagine putting a nest together with only a beak?

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WACKY WALKS

Go for a walk across the room. Break into a run. Hop, skip, and jump. We all move in different ways. So do animals, insects, and birds. Their bodies are shaped in certain ways that allow them to walk and run the way they do. How an animal moves is called its gait.

In this experiment, you're going to try out several animals' gaits to learn how they move. Who knows, maybe you'll find a new way to groove!

QUESTION

Why do animals walk the way they do?

WHAT YOU NEED

Imagination

Lots of open space

WHAT TO DO

FUN FACT

Zoom!

Cheetahs are the fastest animals on land. They can run at over 62 miles per hour — three times as fast as the fastest human runner.

1. Some birds don't fly; they walk. But their walks can look pretty funny. Try waddling like a penguin.
2. Giraffes have long legs and long necks. Try getting on all fours and sticking your neck out. Now try taking long strides.
3. In the ocean, animals move very differently than they do on land. A whale swishes his big tail from side to side to move through the water. Lie on your stomach on the floor with your arms at your sides. Now try swishing your feet from side to side. Can you move across the floor?
4. Rabbits and frogs hop about. They push off of their strong back legs and spring into the air. Make sure you have plenty of space, then try hopping around the room. How far can you go?
5. Humans walk upright on their legs and swing their arms to help them move. Walk around the room, swinging your arms.
6. Some animals, like cats and dogs, walk on their toes. This allows them to move quietly and chase prey. Try walking on your toes as silently as you can. Did anyone hear you coming?
7. Rhinos, and other big mammals, are big and lumbering. They make a lot of noise as they walk. Try stomping around as loud as you can.

WORD to KNOW

gait: how an animal moves.

WHAT'S HAPPENING

Each animal has developed its own way of moving. Birds use their wings to fly; rabbits use their strong hind legs to hop; giraffes use their long legs to stride gracefully across the open plains.

These gaits can also help in case of danger. Birds can fly into the air if they are threatened on the ground. Penguins don't move very fast on land, but they can dive into the water where they are speedy swimmers. Rabbits can hop away very fast. Giraffes can see danger coming from far off, and their strides are so long that they are hard to catch.

Each gait is suited to that particular animal, too. A rabbit would have trouble walking like a giraffe, and a frog would have trouble swimming like a whale. You have special bones in your legs and feet that help you walk the way you do. So you are built just the way you are supposed to walk. But it's fun to pretend!

FUN FACT

Snake in a Tree

If you want to find a rat snake, you may have to look up — in a tree! Rat snakes climb trees to find birds and eggs to eat. Their bodies are specially made to slither up bark.

YOUR NOTES

What was the easiest way for you to move about? What was your favorite way to move? Can you think of other animals whose gaits you could imitate? How about a crab or a snake?

SCIENCE LAB: A GAGGLE OF GEESE

Sorting and classifying are two of the most basic skills everyone learns. Do you put all your toys in one place in your room and your clothes in another place? Do you put your pencils in one section of your backpack and your books in another? This skill helps you to keep order in your world — to understand where things are and what is similar and different about those things. Scientists go through the same process when they observe the natural world. And once they're done sorting, scientists then give names to the groupings they've created.

QUESTION

How do scientists group the animals and plants in our world?

WHAT YOU NEED

Data from the previous experiments

Paper

Pencil

WHAT TO DO

1. For each experiment, look at the data you've gathered.
2. For the leaf experiment, think of ways you can group the leaves you found. Big/small? Pointy/round? Green/yellow? Maple/oak?
3. For the seed experiments, how can you group the seeds? Big/small? Shell/husk? Edible/nonedible? Flying/falling?
4. For the community experiment, how can you group your neighbors? Big/small? Insects/animals/people? Flying/crawling/walking? Fur/feathers/skin? Color?
5. For the habitat experiment, how can you group the habitats? Tree/ground? Hole/nest/house? Brick/twigs/stone?
6. For the food chain experiment, how can you group the foods? Sweet/sour/salty? Breakfast/lunch/dinner? Old/new? Liquid/solid? Vegetable/fruit? Meat/dairy?
7. For the walking experiment, how can you group the animals by their movement? Hoppers? Striders? Swimmers? Flyers?
8. Now find ways to narrow your groups. You're revising your research to be as specific and detailed as you can. This is what scientists do.

WHAT'S HAPPENING

Scientists have formal ways that they classify animals, plants, insects, and so on. They look for a grouping, say all the yellow flowers in a garden. Then they look to see what those yellow-flowered plants have in common and what their differences are. Based on those conclusions, scientists group the plants under one classification or another.

You, however, can classify animals and plants and other things any way you like. But you want your classifications to help you better understand your world. So you should make sure that your group names refer to the way an animal walks, what an insect eats, where a plant grows, and so on. Sorting and classifying are very important to scientists.

YOUR NOTES

How would you classify yourself using the groups above?