Download Flower Dissection Lab

Flower Dissection Lab
Biology Resource Manual Pages 26 and 27
Pre-AP Biology Resource Manual Pages 25 and 26
Introduction
Flowers are the reproductive organs of angiosperms, or
flowering plants. Flowers vary in size, color, and
arrangement. All flowers, regardless of variety, have
the function of increasing the chance of fertilization,
thus ensuring seed formation and the production of
more plants. Flowers contain both nonreproductive
and reproductive structures. In this investigation, you
will examine a flower and identify its nonreproductive
and reproductive parts. You will also observe the male
and female sex cells produced by the flower.
Nonreproductive Anatomy of the Flower
Observe the lily pictured on the next page. Refer to the figure below. Identify
the receptacle, or the structure to which all other flower parts are attached.
Note the sepals in the figure. These are small, leaf like structures above the
receptacle. In the lily that you are observing, the sepals are ornamental.
That is, they look just like the petals. All of the sepals together are called the
calyx. Observe the brightly colored petals inside the calyx. All of the petals
together are called the corolla. These structures make up the
nonreproductive structures.
Nonreproductive Anatomy of the Flower
As you observe the flower, note the number and color of both the sepals and
the petals. Record this information in the appropriate place in the data table
in Observations on your data sheet.
Reproductive Anatomy of the Flower
Refer to the figure below and identify the male reproductive structures, or
stamens. Each stamen consists of an anther and a filament. Count the
number of stamen on the lily and record this information in the data table on
your data sheet. Identity the female reproductive structure, or pistil. Each
pistil consists of an ovary, a stigma, and a style. Count the number of pistils
on your flower and record this information in the data table.
Reproductive Anatomy of the Flower
Sketch the flower in the Reproductive Structure of the Flower section of your
data sheet. On the sketch, label the stamen, anther, filament, pistil, ovary,
stigma, and style.
Reproductive Anatomy of the Flower
Observe the stamen below, the male reproductive structure. This stamen is
magnified using the dissection microscope. Sketch the stamen in the Flower
Stamen section of the data sheet. Label the anther and the filament.
Reproductive Anatomy of the Flower
Below is a cross-section of the ovary of the lily. Observe and sketch the
inside of the ovary. Draw the number and arrangement of the ovary
chambers. The objects inside the chambers are the ovules, or eggs. Label
the ovules, ovary walls, and chambers. Count the approximate number of
ovules in the ovary and record this information in the data table on your data
sheet.
The next slides show sperm containing the male gamete,
pollen, and ovules which are the female gamete, eggs.
These structures have been magnified using a microscope.
The Gametes of a Flower
Below is a picture of the ovule, or egg. Sketch the ovule in the section
labeled Ovule on your data sheet.
The Gametes of a Flower
The stigma of the flower has a moist, sticky texture. Observe what happens
below when pollen brushes against the stigma. Draw the magnified pollen
grains in the section labeled Pollen Grains on your data sheet.
Now answer the questions on the next page.
Use your book as a resource.