Download Botanist 1 Period ______ Date Botanist 2 Background: Flowers are

Botanist 1 ___________________________Period ______ Date________________________
Botanist 2 ___________________________
Bio Lab: Flower Dissection
Background: Flowers are premature fruits and seeds, which are the products of sexual
reproduction. Within the flower, fertilization occurs; this is essential to the formation of the embryo
plant contained in the seed. Seeds are contained in fruit, and neither seed nor fruit is normally
produced unless pollination and fertilization have occurred.
Purpose: To examine the parts of a typical complete flower and become familiar with the terms
used for the various floral organs, or structures. Dissect a flower to discover how its various
structures aid in reproduction.
Problem: How do the parts of a flower aid in reproduction?
Hypothesis (write an “If…,then…” statement that answers the problem question above):
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Structure of a flower:
A complete flower contains all four kinds of floral parts. In order, from outside to inside, they are as
follows:
1. Sepals- modified leaves that protect the flower; together, they make up the calyx.
2. Petals- also modified leaves, brightly colored; together, they make up the corolla.
 The calyx and corolla form the perianth.
3. Stamens- male reproductive structure.
4. Pistil- the female reproductive parts.
Materials:
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flower
colored pencils
tweezers
magnifying glass
Procedure:
1. Locate the outermost layer of flower parts. This is the calyx, which is composed of sepals. Carefully
remove the sepals.
a. Record the number of sepals, attach one, and describe the function in your data table.
2. Identify the corolla; this is petals that form the next layer of flower parts. Carefully remove each
petal.
a. Record the number of petals present, attach a petal, and describe the function in the data table.
b. Do the sepals and petals resemble each other in size and color, or are these structures
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What term is used for the entire floral envelope (calyx and corolla)? ____________
Why are these two whorl parts referred to as “accessory parts”?______________
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What is the function of these two parts?_________________________
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Are your flower parts represented by multiples of 3, 4, or 5? ________________
Is your flower a monocot or dicot? ___________________________
different?
c.
d.
e.
f.
g.
3. Now locate the stamens. These male flower parts should now be exposed. Remove the stamensrecord the number in table. Add a stamen to your data table. Be sure to label the anther and
filament.
a. How does number compare with the number of parts in the calyx and corolla?
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4. The female flower part remains. Most flowers have several carpels fused together, forming a
structure called a pistil. Record the number of pistils in your data table, add the pistil to your table.
Be sure to label the carpel(s), pistil, stigma, style, and ovary.
a. How does this number compare with the other parts of the flower?
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Data:
Flower Part # of parts
Attach one of each part below
Sepals
Petals
(Label the anther and filament)
Stamens
(label the stigma, style, and ovary)
Pistil(s)
Description of function
Analyze and Conclude:
1.
Do flowers usually contain more stamens or carpels? Why do you think this is?
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2.
What does the position of the anthers relative to the position of the stigma suggest about how this
flower is pollinated?
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3.
Using the description of the stigma from the data, suggest reasons for its appearance as it relates to
its function.
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4.
What is the necessity of having a stigma supported by a style?
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5.
Take a look at the prepared slide of renuncula stem. What type of plant is this? (circle one)
What does this info. tell you about the other parts of the plant?
monocot/dicot
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6.
Take a look at the ovary cross section. What is the name of the structure you are looking at?
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7.
Take a look at the cross section of the ovary. How many seeds would be produced?
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