Plants 12 - BIOLOGY JUNCTION

AP Plant Study Guide-8b

Unit 8B – Plants

Know the following:

water potential of a turgid plant cell in pure water
adaptations of hydrophytes
what occurs if guard & surrounding epidermal cells are K+ deficient
how stomata are opened & closed
what must the plant expend for bulk flow of water in the root apoplast
which part of an oat seedling detects the direction of light
effect of gibberellins on the aleurone layer of seeds
how plant hormones determine the bending of plants toward light
what hormone might produce normal growth in a mutant dwarf plant
what can function as a sink in plants
why does photosynthesis decrease in wilting leaves
what are epiphytes
what is chlorosis
what soil characteristics would be the least productive to plant growth
what happens to most water taken up by a plant
how solutes move in plants according to the pressure-flow hypothesis of phloem transport
what causes guttation to occur
why does most of the water in xylem move upward in a tree
what property of water causes cohesion of its molecules
function of companion cells
what 2 elements make up most of the dry weight of plants
what could be the harmful effect of spraying a fungicide on a woodlot
what do carnivorous plants supplement by eating insects
why is nitrogen fixation so important
what would be characteristics of soil well suited for plant growth
what is the function of micronutrients in plants
what elements are micronutrients needed by plants
what elements are macronutrients needed by plants
what is meant by double fertilization
what are some “vegetables” that technically are fruits
why is sexual reproduction an advantage to plants
what is the megaspore mother cell & what does it do
what do male gametophytes produce in plants
name 4 flower parts that are modified leaves
what is the function of a seed’s radicle
what forms pollen on a plant
what do the 2 sperm nuclei fertilize in plants
what causes seed germination
what floral parts are involved in pollination & fertilization
what things can function in signal transduction in plants
what is needed by a short-day plant for it to flower
what type of tropism do vines use to grow toward tropical trees
why do plants use changes in photoperiods instead of air temperature changes to trigger dormancy
what is needed to get poinsettias to bloom early in December
do plant hormones act the same on all root & stem tissues
what hormone is involved in the rapid opening & closing of stomata
what effect do auxins have on stem cuttings that are to be rooted

AP Lecture Guide 10 – Photosynthesis

AP Biology: Chapter 10

PHOTOSYNTHESIS

1. What role do autotrophs fill in the biosphere?

__________________________________________________________________________

2. Indicate the role of each structure within the leaf:

a. stomates _______________________________________________________________

b. mesophyll cells __________________________________________________________

c. thylakoid membranes _____________________________________________________

d. stroma _________________________________________________________________

3. What is the source of oxygen released from photosynthesis?

__________________________________________________________________________

4. In the overview of photosynthesis, indicate the most significant function of:

a. Light reaction ___________________________________________________________

b. Calvin cycle ____________________________________________________________

5. Light is a form of energy known as _____________________________________________

and visible light has a wavelength range of _______________________________________ .

6. Plant light receptors absorb _________________________________________ wavelengths

of light and reflect ___________________________________________wavelengths of light.

7. The porphyrin ring of chlorophyll contains the element ______________________________

and the role of the ring is to ___________________________________________________

__________________________________________________________________________

8. What does chlorophyll do when excited by photons? _______________________________

__________________________________________________________________________

9. Label the diagram and explain the difference between Photosystem I and Photosystem II.

__________________________________________________________________________

10. With 2 different colored pencils, follow the energy paths of both noncyclic and cyclic electron

flow in the diagram.

11. How does cyclic differ from noncyclic photophosphorylation?

__________________________________________________________________________

12. To generate ATP, chloroplasts rely on the ETC to _________________________________

and ATP is synthesized when: _________________________________________________

__________________________________________________________________________

13. Within the thylakoid membrane and stroma, indicate what happens to each of the following:

a. water __________________________________________________________________

b. high energy electrons _____________________________________________________

c. H+ ____________________________________________________________________

d. oxygen ________________________________________________________________

e. NADP+ ________________________________________________________________

f. ADP __________________________________________________________________

14. Where in the chloroplast is the H+ concentration highest? ___________________________

__________________________________________________________________________

15. What happens during carbon fixation? __________________________________________

__________________________________________________________________________

16. List the materials the plant uses during the Calvin cycle and the source of the materials.

__________________________________________________________________________

17. The products of the Calvin cycle are ____________________________________________

__________________________________________________________________________

18. What environmental and internal challenges have forced both C4 and CAM plants to evolve

alternatives to the photosynthesis system used by other plants?

__________________________________________________________________________

19. Why do high oxygen levels inhibit photosynthesis? ________________________________

__________________________________________________________________________

20. What happens during photorespiration and why is it considered bad for plants?

__________________________________________________________________________

21. What evolutionary adaptations to the Calvin cycle are seen in C4 plants like sugar cane?

__________________________________________________________________________

22. Draw a diagram to show the anatomical adaptations seen in C4 plants to accommodate their variation on the Calvin cycle.

23. What evolutionary adaptation to the Calvin cycle is seen in CAM plants like cacti?

__________________________________________________________________________

AP Lecture Guide 29-30 – Plant Diversity

AP Biology: CHAPTER 29 & 30- PLANT DIVERSITY

1. Chart the four phyla of the plant kingdom. Include common names of each, the approximate

number of extant species, and the major characteristics.

a. _______________________________________________________________________

__________________________________________________________________________

b. _______________________________________________________________________

__________________________________________________________________________

c. _______________________________________________________________________

__________________________________________________________________________

d. _______________________________________________________________________

__________________________________________________________________________

2. Why are Charophyceans thought to be ancestors of land plants?

__________________________________________________________________________

3. List several adaptations of land plants significant for terrestrial survival.

__________________________________________________________________________

4. Label the generic diagram to explain Alternation of Generations.

5. Describe a few features common to Bryophytes.

__________________________________________________________________________

6. What is the dominant phase of the moss life cycle?

__________________________________________________________________________

7. List a couple of adaptations of Pteridophytes (ferns) not seen in Bryophytes.

__________________________________________________________________________

8. What is the dominant phase of the fern life cycle? _________________________________

__________________________________________________________________________

9. How is the reduced gametophyte an adaptation for seeded plants?

__________________________________________________________________________

10. What is the significance of the seed? ___________________________________________

__________________________________________________________________________

11. What was the advantage of pollen? _____________________________________________

__________________________________________________________________________

12. List the four phyla of gymnosperms. Which is the most common? _____________________

__________________________________________________________________________

13. Identify five differences between monocots and dicots.

a. _______________________________________________________________________

b. _______________________________________________________________________

c. _______________________________________________________________________

d. _______________________________________________________________________

e. _______________________________________________________________________

14. What is the adaptive value of the flower to plants? _________________________________

__________________________________________________________________________

15. Describe the role of ovaries and ovules in the flowering plants.

__________________________________________________________________________

16. List several features of angiosperms that aid in seed dispersal.

__________________________________________________________________________

Floating Leaf Disk Assay

The Floating Leaf Disk Assay for Investigating Photosynthesis

Brad Williamson

Introduction:

Trying to find a good, quantitative procedure that students can use for exploring photosynthesis is a challenge. The standard procedures such as counting oxygen bubbles generated by an elodea stem tend to not be “student” proof or reliable. This is a particular problem if your laboratory instruction emphasizes student-generated questions. Over the years, I’ve found that the floating leaf disk assay technique to be reliable and understandable to students. Once the students are familiar with the technique they can readily design experiments to answer their own questions about photosynthesis. I plan to add to this page as I have time to elaborate on the technique and provide suggestions for modifications.

Materials:

1. Sodium bicarbonate (Baking soda)

2. Liquid Soap

3. Plastic syringe (10 cc or larger)—remove any needle!

4. Leaf material

5. Hole punch

6. Plastic cups

7. Timer

8. Light source

Optional:

Buffer Solutions

Colored Cellophane or filters

Leaf material of different ages

Variegated leaf material

Clear Nail polish

Procedure:

Prepare 300 ml of bicarbonate solution for each trial.
1. The bicarbonate serves as an alternate dissolved source of carbon dioxide for photosynthesis. Prepare a 0.2% solution. (This is not very much—it’s about 1/8 of a teaspoon of baking soda in 300 ml of water.) Too much bicarbonate will cause small bubbles (CO2)to form on the surface of the leaf which will make it difficult to sink the leaf disk.
2. Add 1 drop of dilute liquid soap to this solution. The soap wets the hydrophobic surface of the leaf allowing the solution to be drawn into the leaf. It’s difficult to quantify this since liquid soaps vary in concentration. Avoid suds. If your solution generates suds then dilute it with more bicarbonate solution.

Cut 10 or more uniform leaf disks for each trial

1. Single hole punches work well for this but stout plastic straws will work as well
2. Choice of the leaf material is perhaps the most critical aspect of this procedure. The leaf surface should be smooth and not too thick. Avoid plants with hairy leaves. Ivy, fresh spinach, Wisconsin Fast Plant cotyledons—all work well. Ivy seems to provide very consistent results. Any number of plants work. My classes have found that in the spring, Pokeweed may be the best choice.
3. Avoid major veins.

Infiltrate the leaf disks with sodium bicarbonate solution.

1. Remove the piston or plunger and place the leaf disks into the syringe barrel. Replace the plunger being careful not to crush the leaf disks. Push on the plunger until only a small volume of air and leaf disk remain in the barrel (< 10%).

1. Pull a small volume of sodium bicarbonate solution into the syringe. Tap the syringe to suspend the leaf disks in the solution.

1. Holding a finger over the syringe-opening, draw back on the plunger to create a vacuum. Hold this vacuum for about 10 seconds. While holding the vacuum, swirl the leaf disks to suspend them in the solution. Let off the vacuum. The bicarbonate solution will infiltrate the air spaces in the leaf causing the disks to sink. You will probably have to repeat this procedure several times in order to get the disks to sink. You may have difficulty getting the disks to sink even after applying a vacuum three or four times. Generally, this is usually an indication that you need more soap in the bicarbonate solution. Some leaf surfaces are more water repellent than others are. Adding a bit more soap usually solves the problem.

Pour the disks and solution into a clear plastic cup. Add bicarbonate solution to a depth of about 3 centimeters. Use the same depth for each trial. Shallower depths work just as well.

1. This experimental setup includes a control. The leaf disks in the cup on the right were infiltrated with a water solution with a drop of soap—no bicarbonate.

Place under the light source and start the timer. At the end of each minute, record the number of floating disks. Then swirl the disks to dislodge any that are stuck against the sides of the cups. Continue until all of the disks are floating.

1. The control is on the left in each image. In the experimental treatment, on the right, leaf disks are rising and floating on the surface.

Sample results:

Time (minutes)	Disk Floating
1	0
2	0
3	0
4	0
5	0
6	0
7	1
8	1
9	1
10	1
11	4
12	7
13	8
14	10

The point at which 50% of the leaf disks are floating is the point of reference for this procedure. By interpolating from the graph, the 50% floating point is about 11.5 minutes. Using the 50% point provides a greater degree of reliability and repeatability for this procedure.