Why Do Plants Have Flowers?

All living things have one main goal in common: to reproduce. Plants are no different. But, how do plants make a new generation? They can use seeds or spores. Flowers are the “factories” where seeds are made and kept safe until they are spread throughout the environment.

Seeds contain a “code” that will tell a plant how to grow, much like how our DNA guides how we develop. The code has two parts – a male and female part. In order for a seed to grow, it needs both parts of the code. The flower is where those parts combine. The male part of one flower, the pollen, connects with an ovule (egg) from another flower. This process is called pollination.

Each flower has specific parts that help it create seeds. Let’s take a look at them:

1.

Pistil: made up of the ovary, style, and stigma – this is the female part of the flower.

2. Stigma: the tip of the pistil, this part is sticky so that pollen grains from other flowers stick to it and travel down to the ovary.

3. Style: the tube that connects the stigma to the ovary. Pollen travels down this tube to get to the ovary.

4. Ovary: part of the flower that stores the ovules (eggs) while they wait to join with pollen grains.

5. Stamen: made up of the anther and filament, this is the male part of the flower.

6. Anther: the top of the stamen, this is where pollen grains are made.7. Filament: the part of the flower that holds up the anther.8. Petals: part of the flower that is brightly colored to attract pollinators. 9. Sepals: part of the flower that protects buds as they grow to become flowers.

How Does Pollination Happen?Flowers attract birds, bees, flies, bats, and other animals that eat nectar. Their bright colors let these animals know where they can find their food. When a pollinator reaches a flower, tiny grains of pollen from the stamen are brushed onto its body and legs.

Then, when the pollinator flies to another flower, some of the pollen grains are caught by the stigma and travel down the style to the ovary, where they combine with ovules. Now, a seed is made!

How Does Pollination Happen?Flowers attract birds, bees, flies, bats, and other animals that eat nectar. Their bright colors let these animals know where they can find their food. When a pollinator reaches a flower, tiny grains of pollen from the stamen are brushed onto its body and legs.

Then, when the pollinator flies to another flower, some of the pollen grains are caught by the stigma and travel down the style to the ovary, where they combine with ovules. Now, a seed is made!

Basic Plant Parts:

Plants have roots, leaves, and stems.

Roots keep plants in the soil and take up water and nutrients. Leaves hold chlorophyll; photosynthesis takes place in the leaves. Flowers allow plants to reproduce. Fruits form from the ovary of a flower; they have seeds in them that spread when they are eaten. The stem holds the plant up.

Basic Plant Parts:

Plants have roots, leaves, and stems.

Roots keep plants in the soil and take up water and nutrients. Leaves hold chlorophyll; photosynthesis takes place in the leaves. Flowers allow plants to reproduce. Fruits form from the ovary of a flower; they have seeds in them that spread when they are eaten. The stem holds the plant up.

Basic Plant Parts:

Plants have roots, leaves, and stems.

Roots keep plants in the soil and take up water and nutrients. Leaves hold chlorophyll; photosynthesis takes place in the leaves. Flowers allow plants to reproduce. Fruits

form from the ovary of a flower; they have seeds in them that spread when they are eaten. The stem holds the plant up.

Beezy the Bee:

This is simply a story the teacher will read and draw on the board prior to handing out the notes pages. Basically, it tells the story of pollination.

One day, Beezy the Bee went looking for nectar. She buzzed happily, landing on a flower and sipping up the nectar. Before she left, she noticed that a lot of yellow dust had stuck to her body. Not too concerned, Beezy went on to the next flower. This time, she absently brushed against a thin tube in the center of the flower. Some of the yellow dust fell off, but Beezy didn’t notice. She was too busy looking for her next meal…

What Beezy did not realize is that she was constantly moving pollen – the yellow dust – from flower to flower. Once transferred, the pollen traveled down the style to the ovary, to fuse with the ovule and form a seed. All Beezy knew was that she wanted more nectar to make honey, and for that she needed to visit the brightly colored flowers.

Guide to Lesson 7 Module Materials:

1. Reproductive Parts of a Flower/Parts of a Plant HandoutFor student use during the dissection activity to serve as a guide during their exploration. (The plant parts section is just a review from prior lessons).

2. Flower Dissection Data SheetFor student use during the dissection activity; students will tape or draw each part of the flower to the appropriate spaces on the worksheet.

3. Why Do Plants Have Flowers? and How Does Pollination Happen?Both handouts are for students to keep as reference materials in their science notebooks; to be passed out after the dissection.

4. Beezy the Bee StoryNot to be copied; for teacher use during the explanation of plant parts and their functions pertaining to pollination.

5. Flower Parts & Pollination WorksheetTo be used as an evaluation that students complete after the explanation phase of the lesson.

6. Flower Parts & Pollination Worksheet Answer KeyFor teachers to use to grade the student worksheet.

Flower Parts and Pollination Worksheet Answer Page

***1. For plants to make seeds, the pollen from the anther of one

flower needs to fertilize the ovule of another flower.2. The seeds are produced in the flower’s ovary, at the base of the

pistil.3. A variety of critters collect pollen and nectar to feed themselves

and their young. These critters also carry pollen from one flower to another and are called pollinators.

4. Name at least four critters that might be pollinators. Answers may vary – bee, hummingbird, fly, moth, bat, beetle

Stigma

Style

Ovary

Petal

Anther

Filament

Sepal