Simple Plants PowerPoint Questions

Simple Seedless Nonvascular & Vascular Plants
PowerPoint Worksheet

Seedless Nonvascular plants

1. Name the 3 divisions of seedless vascular plants and a member of each division.

     a.

     b.

     c.

Division Bryophyta

2. What is the common name for mosses, liverworts, and hornworts?

3. Bryophytes lack what type of tissue?

4. Name the 2 vascular tissues lacking in bryophytes and tell their function.

 

5. What is the 2 stage life cycle of plants called?

6. Name the 2 life cycle stages.

7. which stage is DOMINANT in bryophytes (mosses, liverworts, & hornworts)?

8. How do bryophytes reproduce?

9. Which stage of the moss looks like a lush green carpet?

10. Name the division for moss.

11. Why are moss small plants?

12. Do moss have TRUE roots, stems, or leaves?

13. In what type of area do moss grow?  Give several examples.

 

14.Moss gametophytes must grow close together in moist areas. Give 2 reasons why this is so.

     a.

     b.

15. What covers the outside of a moss plant to prevent water loss?

16. What anchors moss plants?

17. Can rhizoids absorb water like true roots?

18. Where does the sporophyte generation occur on moss plants?

 

19. What is at  the top of the sporophyte?

20. Label the following moss plant.

21. ___________ moss is used by florist. What characteristic makes it useful?

 

22. Because moss will grow on bare ground, it is called a _________ plant.

23. How is peat moss used?

 

24. Give 4 other uses for moss.

 

25. Moss are capable of asexual reproduction. Name and describe 2 types of this vegetative reproduction.

     a.

     b.

26. What are gemmae?

 

27. How are gemmae separate from the parent plant & dispersed?

 

28. Which stage of the moss is haploid and which is diploid?

29. The gametophyte generation produces what 2 cells? 

30. Why do these cells have half the chromosome number?

31. ____________ have a ________ set of chromosomes and reproduce ___________.

32. the sporophyte grows attached to the top of the ______________.

33. Since sporophytes lack chlorophyll, what cellular process are they incapable of doing?

34. How does the sporophyte get its food?

35. What is the setae on a moss plant?

36. How are the moss gametes protected?

 

37. Name the female gametangia & tell what it produces.

38. Eggs of moss are _____________ & ___________.

39. Label the female gametangia.

40.  Name the male gametangia & tell what it produces.

41.How does the sperm cell know the direction in which to swim to the egg?

 

42. Label the male gametangia.

43. The moss ___________ or fertilized egg develops into the ____________.

44. Spores of the sporophyte capsule germinate into young plants called ______________.

45. Protonema develop into the _____________ stage

46. Label the protonema & developing gametophyte in this picture.

47. Label the life cycle of the moss.

Division Hepatophyta

48. ___________ are nonvascular, _________ producing bryophytes.

49. What stage is dominant in liverwort’s life cycle?

50. Describe the liverwort gametophyte.

 

51.Liverworts are found growing where?

 

52. Liverworts need lots of water for ____________.

53. How do liverworts reproduce asexually?

54. How do liverworts reproduce sexually?

Division Anthocerophyta

55._____________ are small, nonvascular ____________ with a dominant, leafy ____________ like liverworts.

56. Where are the antheridia & archegonia in hornworts?

57. Zygotes develop into ______________ sporophytes.

58. Is the horn-shaped sporophyte capable of photosynthesis?

59. Is the horn-shaped sporophyte attached to or separate from the gametophyte?

60. Label the parts of the hornwort.

Seedless Vascular Plants

61.Label these structures on the back of this fern.

62. Name and give an example of a plant in the 4 divisions of seedless vascular plants.

     a.

     b.

     c.

     d.

63. Name the vascular tissues.

64. Do seedless vascular plants go through alternation of generations?

65. Which stage is dominant?

66. How do they reproduce?

Division Psilophyta

67.Describe whisk ferns.

 

68. Do they have true roots, stems, or leaves?

69.How many extant genera are there?

70. Name the root like structures of whisk ferns and tell whether they can or can’t absorb water.

71. How do whisk ferns reproduce asexually?

72. How do whisk ferns reproduce sexually?

73. Make and label a sketch of an aerial branch of whisk with sporangia.

 

 

74. What is the purpose of sporangia?

Division Lycophyta

75. The division Lycophyta contains the ______________ living vascular plants.

76. Club moss are commonly called ______________ ____________.  Explain why this is true.

 

77.Club moss have ________ growing root like ___________.

78. Describe the habitat needed by club moss.

79. Describe the leaves of club moss.

 

80. Are these TRUE leaves? Explain why.

 

81. What is found in the axils of the leaves & what is their purpose?

82. What are strobili?

83. Some club moss are homosporous while others are heterosporous.  Explain what each of these terms means.

     a. homosporous-

     b. heteroporous-

84. Give an example of a homosporous club moss.

85. Lycopodium is used in fireworks. Explain the reason for this.

 

86. What do the spores of Lycopodium look like?

 

87.What is the purpose of each of these structures.

   

88. Give 3 other uses for club mosses.

     a.

     b.

     c.

Division Sphenophyta

89. How many extant species of horsetails are there?

90. Name the living genera of horsetails.

91. What is another name for horsetails?

92. Why are they called this?

93. Describe the stems of horsetails.

 

94. Where does photosynthesis take place in horsetails?

95. How are horsetails anchored?

96. How do horsetails reproduce?

97. Where are their spores found?

98. In prehistoric times, what was true of the size of horsetails?

99. Describe the habitat of horsetails.

100. How do horsetails prevent water loss from the parts of the plant above ground?

101. What special spore dispersing structures are found on the spores of horsetails?

102. Describe how elaters work.

 

103. Label the stem, node, and leaves on this horsetail.

104. Give 3 other uses for  horsetails.

     a.

     b.

     c.

104. Can animals eat horsetails? Why or why not?

 

Division Pterophyta

105. Ferns are in the ____________ group of extant vascular plants.

106. Describe the habitats for ferns.

 

107. How do ferns reproduce asexually?

108. What stage is dominant in the life cycle of the fern?

109. What is the only part of the fern plant that appears above ground?  What parts are found below ground?

110. Fern leaves are called ______________ and are attached to the plant by short stems called ______________.

111. Describe the appearance of newly forming fern fronds and tell what they are called.

 

112. What are sori and where are they found?

113. How are fern spores spread?

114. What forms when a fern spore lands on moist ground and germinates (starts growing)?

115. The prothallus starts what stage in the life cycle?

116. What is the shape of the gametophyte and does it live long?

117. What 2 structures grow ON the gametophyte?

118. Label the gametophyte and the male and female gametangia.

119. Label the parts of a fern.

120. Label the life cycle of the fern.

121. Give 4 uses for ferns.     a.

     b.

     c.

     d.

 

Seed Germination & Detergents

 

Detergent & Seed Germination

Introduction:

Seeds come in different sizes, shapes, and colors. Some are edible and some are not. Some seeds germinate readily while others need specific conditions to be met before they will germinate. Within every seed lives a tiny plant or embryo.The outer covering of a seed is called the seed coat. Seed coasts help protect the embryo from injury and also from drying out. Seed coats can be quite thin and soft as in beans or very thick and hard as in locust or coconut seeds. Endosperm, which is a temporary food supply, is packed around the embryo in the form of special leaves called cotyledons or seed leaves. These generally are the first parts visible when the seed germinates. Plants are classified based upon the number of seed leaves (cotyledons) in the seed. Plants such as grasses and grass relatives can be monocots, containing one cotyledon. Dicots are plants that have two cotyledons.

 Seeds remain dormant or inactive until conditions are right for germination. All seeds need water, oxygen, and proper temperature in order to germinate. Some seeds require proper light also. Some germinate better in full light while other require darkness to germinate.When a seed is exposed to the proper conditions, water and oxygen are taken in through the seed coat. The embryo’s cells start to enlarge and the seed coat breaks open and root or radicle emerges first, followed by the shoot or plumule which contains the leaves and stem.

Many factors contribute to poor germination. Over-watering results in a lack of proper oxygen levels. Planting seeds to too deep results in the seed using up all of its stored energy before reaching the soil surface, and dry conditions result in the lack of sufficient moisture to start and sustain the germination process.

Objective:

The students will be able to describe how some environmental factors affect seed germination.

Materials:

Masking tape, Scissors, 3 ziplock bags, Marker, Forceps, Paper Towels, Metric Ruler, 3 colored pencils, 25 seeds, distilled water, 50 ml graduated, 1% detergent solution, 10% detergent solution, graph paper

Procedure:

  1. Label the 3 zip lock bags: Control, 1% Solution and, 10% Solution.
  2. Cut 6 square pieces of paper toweling to fit each bag.
  3. Place 2 squares in each bag.
  4. Distribute 6 seeds on each side of the paper towel between the plastic and towel.
  5. In the control bag add 25 ml of distilled water completely moistening the paper towel.
  6. In the 1% solution bag add 25 ml of 1% detergent solution making sure to completely moisten the towel.
  7. Do the same to the 10% solution bag by adding 25 ml of 10% detergent solution.
  8. Make sure all bags are sealed tightly.
  9. Place the bags in a dark warm place designated by the instructor.
  10. Write a hypothesis predicting the results of the experiment.
  11. Examine the bags daily for 5 days. Record any changes that might have occurred. If the roots is visible the seed is considered germinated.
  12. Record your date in the table below.
  13. Do not allow your towels to dry out. Moisten each bag with the appropriate solutions in equal amounts.
  14. Measure the root growth of each seed daily from the time it appeared.
  15. Graph the data from the table using the colored pencils to represent each of the zip lock bags.

Number of Seeds Germinated

 

Day Control 1% Detergent Solution 10% Detergent Solution
1
2
3
4
5

 

Average Growth of Germinating Seeds(mm)

Day Control 1% Detergent Solution 10% Detergent Solution
1
2
3
4
5

Graph Title: ________________________________________

Analysis:

1. How many of the seeds germinated after 5 days in distilled water? ________. In 1% solution? _______ in 10% solution? ________.

2. Was there a difference in the number of seeds germinated?

3. In which of the three bags did seeds germinate faster?

4. What was the purpose of the control?

5. Did the detergent strength have an effect on the seed’s germination? If so What was it?

6. Was your hypothesis correct? Why or why not?

7. If it was not, what will you do now?

 

Seed Plants Bi

For the Angiosperms the two variation of this basic design are seen in the two Classes (Monocots versus Dicots) (see fig. 23-2).

 





MONOCOTS
DICOTS
Flower structure arranged in group of three arranged in groups of four or five
Leaves narrow with parallel veins wider with branching netlike veins
Vascular tissue scattered vascular bundles Ring of vascular bundles
Roots Many smaller roots One main taproot
Seed One cotyledon Two cotyledons

Pzsol Photosynthesis

 

 

Photosynthesis

Answer Key:

 

 

All organisms use energy to carry out their life functions. Some organisms obtain this energy from sunlight. The process by which this energy transfer takes place is called photosynthesis. Photosynthesis involves a biochemical pathway in which the product of one reaction is consumed in the next reaction. Autotrophs are organisms that carry on photosynthesis and includes plants and other organisms containing the green pigment chlorophyll. Autotrophs use carbon dioxide and water to make oxygen and the simple sugar glucose. The pigment chlorophyll absorbs light energy from the sun during the light reactions. Accessory pigments also in the chloroplast absorb other wavelengths of light that chlorophyll does not absorb. These accessory pigments are responsible for other colors we see in plants such as red, orange, and yellow. Chloroplasts are surrounded by a double membrane. Inside chloroplasts is a system of membranes arranged as stacks of flattened sacs called granum. Each sac in the stack is called a thylakoid. The thylakoids are surrounded by a solution called the stroma. The dark reactions of photosynthesis take place in the stroma. Most chloroplasts are found in the leaves of plants. The underside of a leaf contains openings called stomata where gases such as oxygen and carbon dioxide enter and leave. These openings or stomata are closed during the hottest times of the day by cells called guard cells.

Pzsol Moss Fern

Moss & Fern Puzzle Solution

Plants that lack tubes to carry food and water are called nonvascular plants. These plants are also known as bryophytes. Most bryophytes are terrestrial and live in moist environments. Water is required so that the sperm can swim to the egg during fertilization. Bryophytes do not produce seeds, but instead produce spores to reproduce. These plants exhibit alternation of generations in their life cycle. Because these plants lack vascular tissue, they are small in  height.

Moss is one example of a bryophyte that grows like a lush, green carpet. The dominant stage in the moss life cycle is the gametophyte. Root like rhizoids attach each gametophyte to the soil but do not absorb water. Both male and female gametophytes exist. The sporophyte generation is attached to the top of the gametophyte. Mosses are called pioneer plants because they often are the first plants to re-enter a barren area. Mosses also help prevent soil erosion. Sphagnum, or peat moss, is harvested and burned as fuel in some countries.

Liverworts and hornworts are nonvascular plants that also grow in moist, shady places. Liverworts have leaflike structures along a stem and lay close to the ground. Hornworts, like algae, have a single large chloroplast in each cell.

Ferns are simple, vascular plants that also lack seeds and reproduce by spores. Tree ferns are the largest ferns. Most ferns have an underground stem called a rhizomes. New leaves of ferns are tightly coiled and are called fiddleheads. Mature fern leaves are called fronds. Spores are produced on the underside of fern fronds.

 

PowerPoint Biology

 

Biology PowerPoint
Lectures
All Materials © cmassengale
Click here to download PowerPoint viewer
 

The POWERPOINTS on this website are COPYRIGHTED. They may be SHOWN in class,
but may NOT be POSTED to ANOTHER WEBSITE! 

KETCHUP DAY 
All teachers and students need one of these “catch up days” now and then.

 

Introduction to Biology
Question Guide
Fauna
Starting a New Year
Cellular Respiration Plant Structure and Function
Characteristics of Life
Question Guide
ADP, ATP, & Cellular Respiration
Question Guide
Seeds & Fruits
Water Properties and More
Water ppt Q’s
Water, Solutions, pH, & Buffers
Cell Cycle & Reproduction
Question Guide Reproduction in Cells
 Protists
Protist Types
Scientific Method
Question Guide
Meiosis
Meiosis – Gamete Production
Question Guide
Meiosis Animation
Mutations
 Fungi

 Protists & Fungi

Lab Safety
Question Guide
Mitosis & Meiosis
Question Guide
 Introduction to Animals
Identifying controls & Variables Mendel’s Genetics
Question Guide
Practice Crosses
Hemophilia – the F8C Gene
Karyotypes & Chromosomes
Invertebrate Overview

 

Metric Measurement
Question Guide
Chromosomes

Genetics Problems
Question Guide

Sponges

Cnidarians & Ctenophorans

Chemistry
Question Guide
DNA Structure
Strawberry DNA
Strawberry Q’s
Unsegmented Worms (Flat & Round worms)
Bioenergetics
Question Guide
DNA & Replication
Question Guide
Annelids
Enzymes
Question Guid
Protein Synthesis
Protein Synthesis2
Question Guide
Mollusks

Clam dissection

Biochemistry of Cells
Question Guide
Macromolecule Chart
DNA Technology
Question Guide
Arthropods

World of Insects

Insect Orders

Macromolecules Taxonomy
Question Guide
Echinoderms

Chordates

Carbohydrates Origin of Life  Question Guide

Evidence for Evolution

Fish
Lipids Evolution   Question Guide

Darwin Versus Lamarck

Amphibians
Proteins Population Genetics Reptiles
Nucleic Acids Bacteria
Question Guide
Birds
Story of the Eagle
Cellular Structure
Question GuideCell Structure (revised)
Question Guide (revised)
Viruses
Question Guide
Mammals
Transport Across Cell Membranes
Question guide
Transport Flash Cards Review
Flash Card Activity
Tonicity Animations
Introduction to Plants
Question Guide
Plant Diversity
Ecology and Notes
Land Biomes
Water Biomes
Ecological Succession
Photosynthesis Reactions
Question Guide 
Mosses to Ferns
Question Guide
What is Ecology?
Question GuideEcosystem Energy Flow
Photosynthesis Gymnosperms & Angiosperms Biomes
Food Energy & Ecosystems

 

Pre AP Biology Biology I

 

Plant Analytical Questions

Plant Analytical Questions

Plant Structures and Function

Part 1: Use the following diagram of a seedling to answer these questions.

  1. What tropisms are being exhibited by the various parts of this seedling?

 

 

 

  1. What hormones are involved in these responses?

 

 

 

Part 2: Use the diagram below to complete lines a – f.

The diagrams represent three conditions of day & night length. A short-day plant, with a critical night length of 14 hours, and a long-day plant, with a critical night length of 8 hours, are grown under each condition. On lines a – f, indicate whether each plant will flower under each condition.

 

Plant Pigments and Photosynthesis

 

Plant Pigments and Photosynthesis

 

Introduction:
In this laboratory you will separate plant pigments using chromatography. You will also measure the rate of photosynthesis in isolated chloroplasts. The measurement technique involves the reduction of the dye DPIP. The transfer of electrons during the light-dependent reactions of photosynthesis reduces DPIP, changing it from blue to colorless.

Exercise 4A: Plant Pigment Chromatography:
Paper chromatography is a useful technique for separating and identifying pigment and other molecules from cell extracts that contain a complex mixture of molecules. The solvent moves up the paper by capillary action, which occurs as a result of the attraction of solvent molecules to the paper and the attraction of the solvent molecules to one another. As the solvent moves up the paper, it carries along any substances dissolved in it. The pigments are carried along at different rates because they are not equally soluble in the solvent and because they are attracted, to different degrees, to the fibers of the paper through the formation of intermolecular bonds, such as hydrogen bonds.

Beta carotene, the most abundant carotene in plants, is carried along near the solvent front because it is very soluble in the solvent being used and because it forms no hydrogen bonds with cellulose. Another pigment , Xanthophyll differs from carotene in that it contains oxygen. Xanthophyll is found further from the solvent font because it is less soluble in the solvent and has been slowed down by hydrogen bonding to the cellulose. Chlorophyll’s contain oxygen and nitrogen and are bound more tightly to the paper than the other pigments. Chlorophyll a is the primary photosynthetic pigment in plants. A molecule of chlorophyll a is located at the reaction center of the photo systems. The pigments collect light energy and send it to the reaction center. Carotenoids also protect the photosynthetic systems from damaging effects of ultraviolet light.

Procedure:
1. Obtain a 250 mL beaker which has about 2 cm of solvent at the bottom. Cover the beaker with aluminum foil to prevent the vapors from spreading. It is also suggested this work be done under a fume hood.

2. Cut a piece of filter paper which will be long enough to reach the solvent. Draw a line about 1.0 cm from the bottom of the paper. See Figure 4.1 below.

Figure 4.1

3. Use a quarter to extract the pigments from spinach leaf cells. Place a small section of leaf on the top of the pencil line. Use the ribbed edge of the coin to to crush the leaf cells. Be sure the pigment line is on top of the pencil line. Use a back and forth movement exerting firm pressure through out.

4. Place the chromatography paper in the cylinder. See Figure 4.2 below. Do not allow the pigment to touch the solvent.

Figure 4.2

 

5. Cover the beaker. When the solvent is about 1 cm from the top of the paper, remove the paper and immediately mark the location of the solvent front before it evaporates.

6. Mark the bottom of each pigment band. Measure the distance each pigment migrated from the bottom of the pigment origin to the bottom of the separated pigment band. Record the distance that each front, including the solvent front, moved in Table 4.1 Depending on the species of plant used, you may be able to observe 4 or 5 pigment bands.

Table 4.1

Distance moved by Pigment Band (millimeters)

Band Number Distance (mm) Band Color
1
2
3
4
5

Distance Solvent Front Moved _________________

Analysis of Results:
The relationship of the distance moved by a pigment to the distance moved by the solvent is a constant called Rf . It can be calculated for each of the four pigments using the formula:

 

Rf = distance pigment migrated (mm)_____
distance solvent front migrated (mm)

Record your Rf values in Table 4.2

Table 4.2

___________________________ = Rf for carotene (yellow to yellow -orange)
___________________________ = Rf for xanthophyll (yellow)
___________________________ = Rf for Chlorophyll a (bright green to blue green)
___________________________ = Rf for Chlorophyll b (yellow green to olive green)

Topics for Discussion:
1. What factors are involved in the separation of the pigments?

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

2. Would you expect the Rf value of a pigment to be the same if a different solvent were used? Explain.

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

3. What type of chlorophyll does the reaction center contain? What are the roles of the other pigments?

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

Exercise 4B: Photosynthesis / The Light Reaction:
Light is a part of a continuum of radiation or energy waves. Shorter wavelengths of energy have a greater amounts of energy. For example, high-energy ultraviolet rays can harm living things. Wavelengths of light within the visible spectrum of light power photosynthesis. when light is absorbed by leaf pigments, electrons within each photosystem are boosted to a higher energy level and this energy level is used to produce ATP and to reduce NADP to NADPH. ATP and NADPH are then used to incorporate CO2 into organic molecules, a process called carbon fixation.

Design of the Exercise:
Photosynthesis may be studied in a number of ways. For this experiment, a dye-reduction technique will be used. The dye-reduction experiment tests the hypothesis that light and chloroplasts are required for the light reactions to occur. In place of the electron accepter, NADP, the compound DPIP ( 2.6-dichlorophenol-indophenol), will be substituted. When light strikes the chloroplasts, electrons boosted to high energy levels will reduce DPIP. It will change from blue to colorless.

In this experiment, chloroplasts are extracted from spinach leaves and incubated with DPIP in the presence of light. As the DPIP is reduced and becomes colorless, the resultant increase in light transmittance is measured over a period of time using a spectrophotometer. The experimental design matrix is presented in Table 4.3.

Table 4.3: Photosynthesis Setup

Cuvettes

1

Blank

 

2

Unboiled Chloroplasts Dark

3

Unboiled Chloroplasts Light

4

Boiled Chloroplasts Light

5

No
Chloroplasts

Phosphate Buffer 1 ml. 1 ml. 1 ml. 1 ml. 1 ml.
Distilled Water 4 ml. 3 ml. 3 ml. 3 ml. 3 ml + 3 drops
DPIP —- 1 ml. 1 ml. 1 ml. 1 ml.
Unboiled Chloroplasts 3 drops 3 drops 3 drops —- —-
Boiled Chloroplasts —- —- —- 3 drops —-

Procedure:
1. Turn on the spectrophotometer to warm up the instrument and set the wavelength to 605 nm by adjusting the wavelength control knob.

2. While the spectrophotometer is warming up, your teacher may demonstrate how to prepare a chloroplast suspension from spinach leaves.

3. Set up an incubation area that includes a light, water flask, and test tube rack. The water in the flask acts as a heat sink by absorbing most of the light’s infrared radiation while having little effect on the light’s visible radiation.

Figure 4.2: Incubation Setup

Flood Light ——-Water Heat Sink——-Cuvettes

 

4. Your teacher will provide you with two beakers, one containing unboiled chloroplasts. Be sure to keep these on ice at all times.

5. At the top rim, label the cuvettes 1,2,3,4, and 5, respectively. Using lens tissue, wipe the outside walls of each cuvette ( Remember: handle cuvettes only near the top). Using foil paper, cover the walls and bottom of cuvette 2. Light should not be permitted inside cuvette 2 because it is a control for this experiment.

6. Refer to Table 4.3 to prepare each cuvette. Do not add unboiled or boiled chloroplasts yet. To each cuvette, add 1 ml of phosphate buffer.

7. Bring the spectrophotometer to zero by adjusting the amplifier control knob until the meter reads 0% transmittance. Cover the top of cuvette 1 with [email protected] and invert to mix. Insert cuvette 1 into the sample holder and adjust the instrument to 100% transmittance by adjusting the light -control knob. Cuvette 1 is the blank to be used to recalibrate the instrument between readings. For each reading, make sure that the cuvettes are inserted into the sample holder so that they face the same way as in the previous reading.

8. Obtain the unboiled chloroplast suspension, stir to mix, and transfer three drops to cuvette 2. Immediately cover and mix cuvette 2. Then remove it from the foil sleeve and insert it into the spectrophotometer’s sample holder, read the % transmittance, and record it as the time 0 reading in Table 4.4 . Replace cuvette 2 into the foil sleeve, and place it into the incubation test tube rack. Turn on the flood light. Take and record additional readings at 5,10,and 15 minutes. Mix the cuvette’s contents just prior to each readings. Remember to use cuvette 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

9. Obtain the unboiled chloroplast suspension, mix, and transfer three drops to cuvette 3. Immediately cover and mix cuvette 3. Insert it into the spectrophotometer’s sample holder, read the % transmittance, and record it in Table 4.4 . Replace cuvette 3 into the incubation test tube rack. Take and record additional readings at 5,10,and 15 minutes. Mix the cuvette’s contents just prior to each readings. Remember to use cuvette 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

10. Obtain the boiled chloroplast suspension, mix, and transfer three drops to cuvette 4. Immediately cover and mix cuvette 4. Insert it into the spectrophotometer’s sample holder, read the % transmittance, and record it in Table 4.4 . Replace cuvette 4 into the incubation test tube rack. Take and record additional readings at 5,10,and 15 minutes. Mix the cuvette’s contents just prior to each readings. Remember to use cuvette 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

11. Cover and mix the contents of cuvette 5. Insert it into the spectrophotometer’s sample holder, read the % transmittance, and record it in Table 4.4 . Replace cuvette 5 into the incubation test tube rack. Take and record additional readings at 5,10,and 15 minutes. Mix the cuvette’s contents just prior to each readings. Remember to use cuvette 1 occasionally to check and adjust the spectrophotometer to 100% transmittance.

Table 4.4: Transmittance (%)

Time (minutes)

Cuvette 0 5 10 15
2 Unboiled /Dark
3 Unboiled/ Light
4 Boiled / Light
5 No Chloroplasts

Analysis of Results:
Plot the percent transmittance from the four cuvettes on the graph below
.

a. What is the dependent variable? ____________________________________________

b. What is the independent variable? __________________________________________

Graph Title: __________________________________________________________________

Graph 4.1

Topics for Discussion:
1. What is the purpose of DPIP in this experiment?

___________________________________________________________________________

___________________________________________________________________________

___________________________________________________________________________

2. What molecule found in chloroplasts does DPIP “replace” in this experiment? _________________

3. What is the source of the electrons that will reduce DPIP? _________________________________

4. What was measured with the spectrophotometer in this experiment? ____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

5. What is the effect of darkness on the reduction of DPIP? Explain.

____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

6. What is the effect of boiling the chloroplasts on the subsequent reduction of DPIP? Explain.

____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

____________________________________________________________________________

7. What reasons can you give for the difference in the percent transmittance between the live chloroplasts that were incubated in the light and those that were kept in the dark?

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________

_____________________________________________________________________________