Reading 8.1 Plant Structures

Reading 8.1 Plant Structures

by Michelle Carrier

​Getting Ready

​You have been learning about different structures animals have that function to help them to survive. Do you think that plants also have structures that help them to survive? For example, animals may have mouths for eating, lungs or gills for breathing, or special structures for moving. You also found out that plants have special structures that help spread seeds so the new plants can grow. In Lesson 5, you learned that plants are producers. This means they make their own food. Think about plants as producers. What structures do you think help them get what they need to produce food?

Open Ended

What structures do you think help plants get what they need to produce food?

Multiple Select

Select ALL the structures below that help plants survive.

• Stems

• Leaves

• Flower

• Sun

​How Do Plants Survive?

​In Lesson 4, you learned that plants use light energy and water to make their own food. But how does the light energy and water get into the plants? Light energy comes into plants through their leaves. Plant leaves come in many different sizes and shapes. Depending on the plant’s environment, you might find plants with large leaves, small leaves, many leaves, or only a few leaves. Just like animals, plants in different environments have different structures.

​The plant in the picture is called Alocacia, but most people call it elephant ear. Can you see why? This plant survives in tropical jungles where there is little light. Its leaves can grow to be more than three feet long. These plants have some of the largest leaves of any plant. Because of all the trees, there is not much sunlight in the jungle. This plant’s large leaves help it to capture as much light as possible.

​Not all plants have large leaves. Duckweed is a plant that grows in water. It floats near the surface of ponds and lakes. Most duckweed leaves are 1/8 of an inch across. Because they grow near the surface of the water, it is easy for them to capture sunlight with their leaves. Duckweed is one of the smallest plants visible without a microscope.

​Plants also need water to make their food. Water enters the plant’s system through the roots. Roots can look very different, but their function is the same—bringing water into the plant. Remember that in Lesson 4 you learned that plants can grow without soil. You read about students who grew basil plants using just water and light. The water and light work together to make the food the plants need to survive.

​You have also learned that plants reproduce by forming seeds. If conditions are just right, the seed sprouts and becomes a young plant. Do you think that seeds look the same in all plants? Look at the pictures of different kinds of seeds in the images.

Open Ended

How are the seeds of the maple tree, the dandelion, and the apple tree different?

​​What Do Helicopters and Parachutes Have to Do with Seeds?

Seeds help plants reproduce, spread out, and grow in new places. Because plants are held in the soil by their roots, they cannot move. To reproduce and grow a new plant, the seeds themselves need to be able to move around. If all the seeds from a plant dropped to the ground around the plant, there would not be room for all of them to get the light and water they need in order to grow. So plants need to be able to spread their seeds over a wider area.

Some people call maple seeds helicopters. The seeds sit at the bottom of a seedpod shaped like a propeller. The propeller allows the seeds to spin as they fall. The spinning slows down the seeds as they fall from the tree and allows the wind to carry them farther away.

​Have you ever picked a dandelion and blown its fluffy little hairs in the wind? If so, you were helping to spread the seeds of the dandelion. Dandelions produce lots of tiny seeds at the bottom of the fluffy little hairs. This allows the seeds to float in the wind just like a parachute! If you have ever opened a milkweed pod or seen its seeds blow in the wind, you know they move like dandelion seeds. Cattails spread their seeds the same way.

​You have probably noticed seeds inside fruits and vegetables that you have eaten. You might not eat apple or orange seeds, but other animals do. The fruit is a package that protects the seeds. Birds, mice, moles, and other animals that eat fruit are often not able to digest the seeds they eat. Unlike plants that stay in one place, animals move around. As they move around, they leave their droppings, and the seeds in their droppings are taken to new locations. In fact, some seeds would never be spread to new places without animals. This is another important way that organisms in an ecosystem interact.

Open Ended

What is your favorite packaging for seeds (AKA fruit)....answer with an emoji if possible.🤓

​Some plants are able to reproduce new plants from one of their own plant parts that is not a seed. A whole new plant can be grown from parts such as leaves, roots, and stems. The spider plant, on the left, is a popular household plant because it is easy to grow, and has baby “spiders” dangling as if they were letting themselves down on a web. These “spiders” are really a new plant sprouted from a flower that most people never even see. The “spider” can be left dangling on the plant or placed in a new pot of soil where it will sprout roots and become a whole new plant.

​Other Ways Plants Grow

​The coleus plant on the right takes a little more work to grow into a new plant. A section of the stem or leaf must be cut and placed in water until roots start to form. Notice in the picture the number of roots of different lengths.

​Reading 8.1 Recap

• All organisms have special structures that perform functions necessary for the population to survive....even plants

  What structures of plants help them to function?

• ​​Look at the Driving Question Board. Are plant populations affected by these main ideas?