Download LAB: Little Black Box

LAB: Flower Power Dissection
Objective: The purpose of this lab is to identify the various reproductive structures of a flowering plant and to gather
an understanding of how angiosperms reproduce.
Instructions: Follow each step of the procedure below.
Background: The most common type of plants on the earth are angiosperms, or flowering plants. These plants
produce flowers for the purpose of reproducing. Other plants, like mosses, ferns, and conifers, do not produce
flowers, and therefore have alternative reproductive structures. Flowers attach to a stem at a point called the
receptacle. Small, specialized leaves called the sepals lay at the base of the flower and served as a protection to the
flower before it bloomed. The colorful leaves of a flower are called the petals, which often attract insects and bees to help the reproductive process.
In the center of the flower there are several different structures. Complete flowers have a stamen, or male reproductive structure that consists of a
filament and an anther. The anther is located at the top of the then filament and holds the male reproductive cells, called pollen. Another tall
structure in the center of the flower is called the carpel, which leads to the female reproductive structures. The top of the carpel is called the stigma,
and is where pollen from the anther of other flowers attach. The long part of the carpel is called the style and serves as a way to get the pollen to
the ovary. An ovule, or egg is located in the ovary of a flower which is where the new seed and protective fruit will develop.
Materials:
1 Flower (Alstroemeria, or other simple flower)
Probe
Dissecting microscope
Dissecting Platform
Razor
Forceps
1 Half Petri Dish
Textbook p. 612-616
Procedure:
_____1. Obtain your supplies
_____2. Look at the flower from the top. You can use a hand lens (magnifying glass) to make it larger if you like. Draw and label what you see
as“Diagram 1: The Complete Flower”. Label the sepals, petals, anther, filament, stigma, style, & ovary.
_____3. Using the razor, carefully remove the petals (ONLY) from the flower. Be sure to avoid cutting the base of the flower.
_____4. Using the razor, carefully remove one of the stamen from the base of the flower.
_____5. Using the forceps, place the stamen in the half Petri dish and bring into focus using the dissecting microscope.
_____6. Draw and label the parts of the stamen (anther, filament, pollen grains) that you see as “Diagram 2: The Stamen”. Label which are 1N or
2N. Remove and rinse the Petri dish.
_____7. Using the razor, remove all of the stamen from the flower.
_____8. Using the forceps, place the carpel in the half Petri dish and bring into focus using the dissecting microscope.
_____9. Draw and label the parts of the carpel (stigma, style, ovary) that you see as “Diagram 3: The Carpel (Whole)”. Label which are 1N or 2N.
Circle the site where pollination would occur. Using the forceps, remove the carpel back to the dissecting platform.
_____10. Using the razor, gently cut the carpel in half lengthwise.
_____11. Using the forceps, place one half of the carpel cut-side up into the half Petri dish and bring into focus using the dissecting microscope.
_____12. Draw and label what you see (stigma, style, ovary, ovule) in “Diagram 4: The Carpel (Longitudinal Dissection)”. Place a box around the
site of fertilization.
_____13. Clean all materials, throw flower parts away and return dissecting equipment.
LAB: Seed Time
Objective: The purpose of this lab is to identify the various structures of a seed and understand their development and dispersal.
Instructions: Follow the instructions below.
Materials: Corn & pea pods in petri dish, germinating peas in petri dish, dissecting microscope, forceps, textbook p.616-621
Procedure:
1. Obtain materials.
2. Place the half petri dish with the cut open corn kernel and observe it under the dissecting microscope. Draw and label what you see
(seed coat, endosperm, embryo) as “Diagram A: The Corn Seed”.
3. Observe the peas and pea pod. Draw the peas and pea pod as “Diagram B: Peas in a Pod”. Label what you see (seeds, ovary).
4. Observe the germinating peas under the dissecting microscope. Draw and label what you see (use figure 24-14 in your text to help) as
“Diagram C: Germinating Peas”.
5. Clean forceps, and return along with petri dishes. Put away dissecting scope. Make sure your area is clean!
You are now complete with the procedure and will need to complete the analysis questions on the back.
Adapted from UNIT 4: Flower Dissection Lab
CP Biology I, Mr. Doc Miller
Observations:
Diagram 1: The Complete Flower
Diagram 3: Pollen Wet-Mount
Diagram 5: The Carpel (Longitudinal Dissection)
Diagram 2: The Stamen
Diagram 4: The Carpel (Whole)
Diagram 6: Flower Ovule Wet-Mount
Adapted from UNIT 4: Flower Dissection Lab
CP Biology I, Mr. Doc Miller
Analysis:
1.
What is the function (purpose) of a flower? How have they contributed to the widespread distribution and diversity of
angiosperms?
2.
a. What is another name for “flowering plants” and what 2 categories can they be divided into?
b. What are differences between these 2 categories in relation to plant structures?
c. Which category is your flower in, and how do you know?
3.
a. List the male reproductive structures of a flower.
b. List the female reproductive structures of a flower.
4.
Create a flowchart for the process of reproduction for the flowering plant from flower to seed.
5.
What is the difference between pollination, fertilization, and germiniation?
6.
Describe what is meant by “double fertilization”?
7.
The question "The tomato: is it a fruit, or is it a vegetable?" found its way into the United States Supreme Court in 1893. The
court ruled unanimously in Nix v. Hedden that a tomato is correctly identified as, and thus taxed as, a vegetable, for the
purposes of the 1883 Tariff Act on imported produce. Would you agree with their ruling? Why or why not?
Hint: For questions 8-10 review pages 619-620 in your textbook.
8.
How is it possible to keep seed packets on store shelves for months and still have the seeds develop into viable plants when
planted?
9.
We’ve learned plants are photosynthetic organisms, but when they are first planted they are underground. So, how do they
have the energy required to fuel their initial growth?
10.
Plants are sessile (don’t move place to place) so how is it possible to see the same plant in different places around the world?
Adapted from UNIT 4: Flower Dissection Lab
CP Biology I, Mr. Doc Miller