Name: ______Period:_____

Flower Dissection

A good way to learn about the reproductive parts of a plant is by dissecting a flower.

Pre-Lab Questions:

  1. What type of plants produce flowers? Circle Answer: Gymnosperms, Angiosperms
  1. Why do plants produce flowers?
  1. What are the reproductive parts of the flower?

______and ______

  1. List and define the three parts of the Pistil.

·  ______

·  ______

·  ______

5. List and define the two parts of the stamen.

·  ______

·  ______

Label all flower structures


Observation and Identification

Start by identifying each main outside part of the flower. Beneath the petals, there should be smooth, leaf-like projections called sepals. The male part of the flower is called the stamen; there are usually multiple stamens on each flower. The long stalk of the stamen is called the filament. At the top of the filament is the anther, which holds pollen. The female part of the flower is called the pistil. At the top of the pistil is the stigma, which collects pollen and carries it down though its hollow body, called the style, to the ovary, where the pollen fertilizes the flower's eggs. Some flowers have all male or all female parts (melons and pumpkins for example), and are called imperfect. Most flowers are perfect: they have both male and female flowers.

  1. Draw and color your flower below. Use colors that represent your plant. Label the following parts: sepals, stamen, filament, anther, pistil, stigma, style.
  1. Make the following observations of your flower and record your findings below:

# Sepals
# Petals
# Stamen
Circle One: Monocot or Dicot
Why: / Draw a picture of how you would expect the vascular bundles in this flower’s stem to appear:


Dissection

  1. The first step in this dissection is to remove the sepals and petals, by pulling them down toward the stem. Use a microscope to look at the tip of the petal on a low magnification. Draw your observations

What is the petal's texture like under the microscope?


  1. Next, remove the flower's stamens; break or cut them off of the stem. Examine the pollen with a microscope. Make a drawing of the pollen.


3. After you have finished with the pollen, remove all parts except the pistil so that it remains alone on the stem. Carefully cut the pistil in half lengthwise, making sure that your fingers are out of the way. Use your microscope to look at the inside. You should be able to see that the style is a long, hollow tube that carries pollen from the stigma to the ovary. You might be able to see tiny eggs, or ovules, in the pistil's ovary. Draw your observations below:


Analysis

1.  What is the difference between the sepals and petals?

2.  How does a pollen grain get to the stigma of a pistil?

3.  How might the odor of the petals help in pollination?

4.  Which parts of the flower develop into the seeds?

5.  Which parts develop into the fruits?

Conclusion

1.  How does the structure of the stigma aid in pollination?

2.  What type of plant do you have in this lab, an angiosperm or gymnosperm? Explain