AP Biology
Plant Structure and Function Lab
Chapters 35-36, and parts of 41
Instructions: You will use your textbook as a reference for the lab work you will do in
the next few days. You will need to read the assigned pages in their entirety and then
refer to them as you do the lab activities.
The emphasis of this work is the relationship between structure and function.
You will be given lab activities on the structure and function of leaves, stems, roots,
seeds, flowers and fruit. You may complete the activities in any order you choose. The
activities must be completed by Tuesday, Feb. 8 at the end of class. If you need time
on your own to complete these activities, you are responsible for making that extra
time.
Use colored pencils to create your drawings.
This is a major lab grade. Please be sure the completed lab is neat and
organized.
I.
Leaves (pages 748-751)
A. Leaf Cross Section
1. Draw and label the leaf cross section on page 750 of your
textbook. Write the functions of each structure beside the labels.
2. Using the Syringa lilac slide, locate the following parts of the leaf.
Sketch the slide and label visible structures.
Epidermis
Palisade cells
Spongy layer
Vascular bundle
Xylem
Phloem
Air space
Stoma (stomata pl.)
Guard cells
Cuticle layer
3. Write a paragraph discussing how leaf structure contributes to
the efficiency of the process of photosynthesis.
4. Predict adaptations that would be found in leaves located in the
following environments.
a. Desert
b. Tropical rain forest
c. Aquatic environment
B. Stomata and Guard Cells
1. Break a leek leaf almost in half so that the clear epidermis is the
only tissue connecting the leaf halves. Place a small piece of the
epidermis on a microscope slide and add one drop of water.
Observe the epidermis first under low power, then medium, then
high. Draw the stomata and guard cells, as well as the
epidermal cells surrounding them. Label all structures.
2. Write a paragraph discussing the factors that cause the stomata
to be open during the day and closed at night. Under what
circumstances might the stomata be closed during the day?
II.
III.
Stems (pg. 744-747)
A. Primary Stems
1. Sketch and label the following structures on a typical monocot
stem, Zea mays (corn), and a dicot stem, Heliathus (sunflower).
You should have two sketches for this section.
Cortex
Epidermis
Vascular bundle
Xylem
Phloem
Pith
2. Which of the tissues above functions in:
a. Support?
b. Protection?
c. Transport?
d. Food storage?
e. Growth?
3. Write a paragraph comparing and contrasting a monocot
herbaceous stem, a dicot herbaceous stem, and a woody stem.
4. Draw and label the tracheid cells of xylem tissue and sieve-tube
elements of phloem tissue. Below the drawings, briefly explain
the main difference between tracheids/vessel elements and the
sieve-tube elements/companion cells. (Use pages 737-738)
5. Sketch the slide of the sieve cells and label any parts you can
identify.
B. Secondary Stems
1. Use the cross section of the tree provided to
a. Sketch and label and secondary tissues
b. How old is the stem?
c. What primary tissues produce secondary tissues?
Explain how the primary tissues give rise to the
secondary tissues.
C. Woody Twig
1. Use the directions on the twig anatomy activity to complete the
handout provided. You may choose to use the dissecting scope if
needed.
Roots (739-743)
A. Root Cross Section
1. Use the dicot root slide from Ranunculus to sketch and label the
following.
Cortex
Endodermis
Xylem
Phloem
Epidermis Stele
Pericycle
Pith
2. Which tissues function in:
a. Protection?
b. Absorption?
c. Transport?
d. Food storage?
3. Describe the role of the endodermis in the absorption of water
and minerals. (See page 741)
4. Obtain the transverse section of the carrot and complete the
directions on the carrot lab.
5. Use the monocot root slide to sketch a monocot root. What are
the differences between a monocot root and a dicot root?
B. Longitudinal Root Cross-Section
1. Using the Alium root tip to sketch and label the following:
Root hair
Zone of maturation
Zone of Elongation
Apical meristem
Root cap
2. Describe the purpose/function of:
1. Root hairs
2. Apical meristem
3. Root cap
3. Why are root hairs found only in the zone of maturation and
above.
IV.
Flower (840-848)
A. Structure:
1. Using the flower diagram on page 840, sketch and label the
following parts of a flower.
Sepal
Pistil/Carpel
Petal
Stigma
Stamen
Style
Anther
Ovary
Filament
Ovule
Receptacle
2. Remove the floral parts and identify the reproductive structures
in the live flower provided.
3. Place the stamen under the dissecting microscope and observe
the anther.
4. Remove some pollen and observe under the light microscope
(dry mount with a coverslip). Sketch the pollen grains. You may
use the Lilium pollen/anther slide for comparison.
5. Using the scalpel, cut the carpel longitudinally. View with the
dissecting microscope and sketch. Label the ovary and the
ovules. You may use the Lilium ovary slide for comparison.
6. Differentiate between the following:
a. Complete and incomplete flowers
b. Perfect and imperfect flowers
c. Monoecious and diecious flowers
B. Fertilization:
1. Write a paragraph describing double fertilization in flowering
plants. Explain why double fertilization is important and
efficient.
V.
Seeds (We’ll do as a class)
VI.
Fruit (pg. 760-762)
1. What does a fruit develop from?
2. Describe each of the following types of fruit and give an example
of each:
a. Simple fruit
b. Aggregate fruit
c. Multiple fruit
3. Distinguish between a dehiscent and indehiscent dry fruit. Give
an example of each.
4. What purpose do fruits serve in the success of flowering plants.