Chapter 35-39 Reading Guide Unit 6

AP Biology Reading Guide Fred and Theresa Holtzclaw

Chapter 35: Plant Structure, Growth, and Development

Copyright © 2010 Pearson Education, Inc. - 1 -

Name Period

In this unit on plants, the challenge for students will be to learn the new vocabulary. As we work through this unit, you will find an emphasis on labeling and explaining plant diagrams and specific directions for which terms you should know.

Concept 35.1 The plant body has a hierarchy of organs, tissues, and cells

1. This concept is organized into three sections—plant organs, tissues, and cells. Begin by defining a tissue and an organ.

2. The three plant organs are , , and .

3. On Figure 35.2, label the shoot system, root system, apical bud, axillary bud, and root system.

4. Define root and then explain the difference between a taproot and lateral roots.

Root

Taproot and lateral roots





5. This photograph shows the root hairs of a radish. What is the function of root hairs?

6. What is the advantage of apical dominance to a plant?

7. The main function of a leaf is .

8. What are five additional functions that modified leaves can perform?

9. Plants have three types of tissues. Place the name of each tissue type and its function in the table below.

Tissue type Function

10. What is the function of the cuticle?

11. Xylem conducts .

12. Xylem transport tends to be in one direction, but phloem transport is more complicated. Explain the pattern of sugar flow in phloem tissue.

AP Biology Reading Guide Chapter 35: Plant Structure, Growth, and Development


Fred and Theresa Holtzclaw

13. The two major tissues of the ground tissue system are pith and cortex. Where are they found in the plant?

14. Plants have five major types of cells. Below you will find a picture of each cell type. Give the major function of each cell type. Specific questions may follow your general description of the cell type.

Parenchyma cells Function

Collenchyma cells

Sclerenchyma cells

Xylem cells

Label vessel elements, tracheids, and pits.




15. Compare and contrast the following structures:

Tracheids and vessel elements

Sieve tube elements and companion cells

16. At the end of this first extensive concept, do not lose sight of the big picture. Complete the following summary charts.

The three plant organs are

The three basic plant tissues are

The five basic plant cells are

Concept 35.2 Meristems generate cells for new plant organs

17. What is the difference between indeterminate growth and determinate growth?

Label companion cell, sieve tube element, and sieve plate.

Phloem cells




18. Although plants generally show indeterminate growth, what are three examples of plant parts that show determinate growth?

19. Based on the length of their life cycle, plants are categorized into three groups. Explain what each category means below, and provide an example.

Annuals

Biennials

Perennials

20. Plants are capable of indeterminate growth because they have perpetually embryonic tissues

called .

21. Explain the following relationships.

Apical meristems and primary growth

Lateral meristems and secondary growth

Primary growth and secondary growth

Concept 35.3 Primary growth lengthens roots and shoots

22. The figure below shows an image that is like a slide many students study in a mitosis lab and is labeled for this lesson as the “Primary growth of a root.” Label the nine structures shown in the figure: cortex, vascular cylinder, epidermis, apical meristem, root cap, root hair, zone of differentiation, zone of elongation, and zone of cell division.




23. Explain what events occur in the zone of cell division, zone of elongation, and zone of differentiation.

24. In most roots, the xylem and phloem is a solid cylinder of vascular tissue located in the center of the root and called the stele. The figure below shows the stele of a dicot root. Label the xylem, phloem, endodermis, and pericycle. Also define the two new terms as indicated.

Endodermis

Pericycle

25. Why must new roots formed by the pericycle originate in the center of the root?




26. From Figure 35.16, label shoot apical meristem, leaf primordia, young leaf, developing vascular strand, and axillary bud meristems.

27. What structure in this figure is responsible for primary growth?

28. It is possible to tell a young eudicot from a monocot by the structure of the stem. In the following figure, label the eudicot, monocot, epidermis, and vascular bundles.

29. How is the arrangement of vascular bundles different in monocot and dicot stems?




30. To understand the process of photosynthesis, students are expected to know leaf structure in greater detail. Using Figure 35.18, label each structure just as shown in the text.

31. What gas critical to photosynthesis enters the leaf through stoma?

32. What is lost through the stoma that leads to transpiration?

33. Is this a C3, C4, or CAM leaf?

Concept 35.4 Secondary growth adds girth to stems and roots in woody plants

34. Primary growth arises from apical meristems and results in of roots,

stems, and leaves. Secondary growth arises from and

cambium and results in increased of roots and stems.

35. Explain what is produced by these structures.

Vascular cambium

Cork cambium




36. Read the text that accompanies Figure 35.19 and then answer these questions.

a. What results in primary growth of the stem?

b. What cells are formed to the inside and the outside of the vascular cambium?

c. What is the difference in the formation of primary xylem and phloem versus secondary xylem and phloem?

37. What vascular tissue forms the bark, and what is the function of the bark?

38. What tissues are included in the bark of a tree?

39. On this figure, add these labels: cork cambium, cork, periderm, bark, growth ring, secondary xylem, secondary phloem, and vascular cambium.

40. Look back at the stem in Figure 35.19 and find the horizontal slits in the bark, known as lenticels. You may have noticed lenticels on the young twigs of trees or shrubs. What is the function of lenticels?

Concept 35.5 is omitted. These topics have not been included on recent AP Biology

exams. Testing Your Knowledge: Self-Quiz AnswersNow you should be ready to test your knowledge. Place your answers here:

1. 2. 3. 4. 5. 6.


Chapter 36: Resource Acquisition & Transport in Vascular Plants


Name Period

Concept 36.1 Land plants acquire resources both above and below ground

1. Competition for light, water, and nutrients is intense among the land plants. Let’s look first at adaptations to increase light capture. How do plants reduce self-shading?

2. What triggers self-pruning?

3. There are different leaf orientations, and each orientation affects light capture. Compare the following as to the type of plant that has each orientation, and describe the advantage.

Orientation Type of Plant Advantage

vertical leaf orientation

horizontal leaf orientation

4. What are mycorrhizae, and what is their role in resource acquisition?

Concept 36.2 Transport occurs by short-distance diffusion or active transport and long-distance bulk flow

This section gives you a good review of the transport mechanisms you studied in Chapter 7. The information in the next group of questions should be familiar to you. Also, many AP courses do AP Laboratory 1, Diffusion and Osmosis, along with Chapter 7. It covers the concept of water potential, so now might be a good time to review that lab activity.

5. What is passive transport?

6. What is active transport?

7. What is the role of transport proteins?

Chapter 36: Resource Acquisition and Transport in Vascular Plants




8. What are the most important plant cell transport proteins? How do they work?

9. What is membrane potential? How can it be established?

10. Explain cotransport.

11. What is osmosis?

12. Plant cells have a rigid cell wall, which adds another factor that affects osmosis: pressure. Define water potential.

The equation for water potential is = s + p,, where is water potential, s is solute potential, andp is the pressure potential. The understanding of this formula is an objective from Laboratory 1 in the AP Laboratory book.

13. By definition, what is the s of pure water?

14. How does adding solutes to pure water affect water potential?

15. The solute potential of a solution is therefore always . (negative or positive)

16. What is pressure potential? Under what conditions will it decrease?

DCB

A



17. What is the water potential on the left side of tube A? Why?


18. Is the water potential on the right side of tube A positive or negative?

19. Explain, in terms of water potential, why the level of the liquid is higher on the right side of tube A.

20. In tube B, pressure is being applied on the right side. This is much like the pressure exerted by the cell wall when a plant cell takes up water. Explain, in terms of water potential, why the level of liquid is the same on both sides even though the two solutions are not isotonic to each other.

21. To summarize, water moves from regions of water potential to regions of

water potential.

22. Define these terms:flaccid

turgid

plasmolysis

23. In the figure below, a plant cell that has an initial water potential of –0.7 MPa is placed into two different conditions. Explain, in terms of water potential, what is happening in each case.

a.

b.



24. What are aquaporins?


25. There are three major pathways of transport between plant cells. On the sketch, label and explain:

transmembrane route

apoplast

symplast

26. What is bulk flow?

Concept 36.3 Water and minerals are transported from roots to shoots

27. On the sketch, use colored pencils to trace the uptake of water and minerals from root hairs to the xylem and phloem in a root, following a symplastic route and an apoplastic route. Then, label each of the following elements: root hair, plasma membrane, plasmodesmata, stele, endodermis, Casparian strip, symplastic route, and apoplastic route.



28. What is the role of the Casparian strip?


29. Write a short essay to explain the movement of water from the soil into the stele of the root, using all the terms in question 27.

30. What is transpiration?

31. There are two mechanisms that pull water up through the plant, from roots to leaves. Explainroot pressure.

AP Biology Reading Guide Chapter 36: Resource Acquisition & Transport in Vascular Plants



32. The second mechanism that pulls water up through the plant is transpiration-cohesion-tension. Refer to this sketch in your text. Note that water is moving from a region of high water potential to a region of lower water potential. The arrow on the left side of the figure shows this gradient. Beginning from where you stopped in question 29, write an essay to explain the movement of water from the roots to the leaves. Include each of these terms in your essay, and label them on the figure: lower water potential, higher water potential, hydrogen bonding, adhesion, cohesion, xylem tubes, and stomata.




Concept 36.4 Stomata help regulate the rate of transpiration

33. Leaves generally have large surface areas and high surface-to-volume ratios. Give an advantage and disadvantage of these traits.

advantage

disadvantage

34. Plants lose 95% of their water through stomata! What controls the amount of water loss?

35. On the sketches, label the guard cell, stomata, K+, and H2O. Explain why the stoma opens when K+ accumulates in the guard cells.

36. Three types of stimuli can cause guard cells to open. Name and explain how each one works.

Stimulus for Stomatal Opening

and Closing

Explanation




37. What plant hormone is produced in response to water deficiency?

38. List four different physiological or morphological adaptations of xerophytes, and explain how each of them reduces water loss.

Concept 36.5 Sugars are transported from leaves and other sources to sites of use or storage

39. What is translocation?

40. What is a sugar source, and what is a sugar sink? Give an example of each.

41. What cell types transport the sugars?

42. Explain the process of pressure flow by annotating the figure below. Refer to your text, and divide this process into four steps.




43. Study Figure 36.21. How do aphids feed? When houseplants are infested with aphids, why is there a sticky mess on the floor around them?

Concept 36.6 The symplast is highly dynamic

44. Give two specific signals that move through the symplast, and describe the function of each signal.

Testing Your Knowledge: Self-Quiz AnswersNow you should be ready to test your knowledge. Place your answers here:

1. 2. 3. 4. 5. 6. 7.

8. 9. 10.


Chapter 37: Soil and Plant Nutrition


Name Period

Concept 37.2 Plants require essential elements to complete their life cycle

1. What is an essential nutrient?

2. What are the nine macronutrients? List them in order of relative abundance in plants. (You may use atomic symbols.)

3. What is a primary role of magnesium?

4. What three macronutrients are most commonly deficient? You should notice that these are the same three nutrients found in most fertilizers.

Concept 37.3 Plant nutrition often involves relationships with other organisms

5. Which nutrient is most limiting to plant growth on a global scale?

6. Plants have mutualistic relationships with bacteria that help make nitrogen more available. Nitrogen-fixing bacteria such as Rhizobium are able to convert atmospheric nitrogen (N2), which plants cannot use, to ammonia (NH3), which they can use. Review the nitrogen cycle by labeling this diagram.





7. Where is the nitrogen-fixing bacterium Rhizobium found?

8. The principle of crop rotation employs alternation of a crop that depletes nitrogen with a legume crop that fixes nitrogen. In the United States, this often means alternation of corn with soybeans. Which of these two crops is the nitrogen depleter? The nitrogen fixer?

9. How do mycorrhizae enhance plant nutrition?

10. In many parts of the eastern United States, garlic mustard has become a serious pest. What is its negative impact on native species, and how does it appear to do this?

11. What is an epiphyte? Name three different plant types that are epiphytic.

12. Dodder and Indian pipes are nongreen, nonphotosynthetic flowering plants. How do they obtain nutrients?

AP Biology Reading Guide Chapter 37: Soil and Plant Nutrition



13. Carnivorous plants such as the Venus flytrap and sundews are photosynthetic. Why, then, do they capture insects?


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Chapter 38: Angiosperm Reproduction and Biotechnology


Name Period

Concept 38.1 Flowers, double fertilization, and fruits are unique features of the angiosperm life cycle

This may be a good time for you to go back to Chapter 29 and review alternation of generation and the terms associated with it. Figure 29.5 would be a good starting point. Then, review Concepts 30.1 and30.3 on angiosperm life cycles. The angiosperm life cycle has three unique features, all of which start with the letter F, a good memory aid: Flowers, Fruits, and double Fertilization. You will want to remember these!

1. On this sketch of a flower, label all floral parts and give the function of each. Label also thestamen and carpel. Then, circle the flower parts that are essential for reproduction.

2. What is another name for the microsporangia?

3. Each microspore mother cell undergoes meiosis to form four haploid .

4. Each microspore undergoes mitosis to produce the male .

5. The male gametophyte is composed of only two cells. Name each cell, and tell what will come from each of them.

Male Gametophyte Cells What does cell produce?





6. What makes up a pollen grain?

7. Label these parts: anther, pollen sac, microspores, male gametophyte, pollen grain, generative cell, tube cell, megasporangium, megaspore mother cell, embryo sac, surviving megaspore, polar nuclei, synergids, and egg.

8. Meiosis in the female part of the plant produces four megaspores. How many survive?

9. What occurs in pollination? Annotatethe figure to the right to explain pollination.

.

AP Biology Reading Guide Chapter 38: Angiosperm Reproduction and Biotechnology



10. List five modes of pollination. For each mode, describe a feature of the flower that aids pollination.

Mode Feature of Flower

11. Study the section in this concept under the heading “Double Fertilization” very carefully. Label the figures below to show two sperm nuclei, pollen tube, female gametophyte, ovule, synergids, polar nuclei, egg, and zygote. Describe what is happening in each sketch.

12. Study the figure on the left above. You should be able to count a total of 7 cells and 8 nuclei. Which of these are fertilized in double fertilization?

13. When the polar nuclei are fertilized, what is formed?




14. The chromosome number of endosperm is (a) haploid, (b) diploid, or (c) triploid.

15. The chromosome number of the zygote is (a) haploid, (b) diploid, or (c) triploid.

16. What is the role of the endosperm?

17. After double fertilization, what does each ovule become?

18. After double fertilization, what does each ovary become?

19. Let’s compare the seeds of eudicots and monocots. How many cotyledons does each type have?

20. What is the function of a seed coat?

21. What part of the embryo plant emerges first?

22. What are some mechanisms that maintain seed dormancy?




23. Below are sketches of a bean seed and a corn seed. Label them to show: monocot, eudicot, cotyledons, radicle, hypocotyl, epicotyl, seed coat, and endosperm. You may use the same term several times.

24. What is imbibition?

25. To a botanist, a fruit is a ripe . It does not have to be sweet! A pea pod is a fruit. A green pepper is a fruit.

26. An important function of the fruit is to aid in dispersal. What are three primary methods of dispersal?

Concept 38.2 Flowering plants reproduce sexually, asexually, or both

27. Asexual reproduction in plants is also known as vegetative propagation. Describe three different types of asexual reproduction in plants.

28. Why is it important for plants to have mechanisms to prevent self-fertilization?




29. What are two mechanisms to prevent self-fertilization?

Concept 38.3 Humans modify crops by breeding and genetic engineering

30. Humans have used selective breeding to develop useful varieties since the dawn of agriculture. Today, biotechnology has accelerated the introduction of desirable traits. List four genetically modified plant species, and describe the advantage each species shows.

a.

b.

c.

d.

31. Genetically modified organisms (GMOs) offer great promise but are also controversial. What are three of the possible risks?

a.

b.

c.


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Chapter 39: Plant Responses to Internal and External Signals


Name Period

Concept 39.1 Signal transduction pathways link signal reception to response

This concept brings together the general ideas on cell communication from Chapter 11 with specific examples of signal transduction in plants. As with animals, plants have receptors that trigger signal transduction pathways when activated. Let’s begin with a review of three steps in signal transduction.

Step 1: Reception. Cell signals are detected by receptors that undergo changes in shape in response to a specific stimulus.

Step 2: Transduction. Transduction is a multistep pathway that amplifies the signal. This effect allows a small number of signal molecules to produce a large cellular response.

Step 3: Response. Cellular response is primarily accomplished by two mechanisms:a. increasing or decreasing mRNA productionb. activating existing enzyme molecules

1. Have you ever seen a shriveled potato sending out skinny, pale sprouts? What is this called?

2. If you move the potato into the light, the sprout will respond by forming short, sturdy stems and broad, green leaves. What is this response to light called?

3. The figure below gives a specific example of a signal transduction in plants for the greening or de-etiolation response described above. Label these parts of the figure: reception, transduction, response, phytochrome, signal, Ca2+ channel, second messenger (cGMP), protein kinase, transcription factor, and DNA.





4. Return to the figure and explain how the light signal causes the greening response. You may choose to number the steps, as shown in the figure in your text.

5. What are the two second messengers in this pathway?

Concept 39.2 Plant hormones help coordinate growth, development, and responses to stimuli

6. Both plants and animals have hormones. The definition of a hormone has three parts. What are they?

7. Plant physiologists think the term hormone as defined above doesn’t quite fit plants. What term do they use instead?

8. What is a tropism?

9. The sketch below describes early experiments on phototropism conducted by Charles and Francis Darwin. What can be concluded from these experiments?

CONCLUSION




10. Here is a sketch of the Boysen-Jensen experiment. What conclusions can be drawn from it?

CONCLUSION

11. Boysen-Jensen’s work was published in 1913. In 1926, Frits Went modified the experiment using agar cubes with a chemical from the coleoptile tips. Explain the results of this experiment.




12. What name did Went give to this chemical messenger? What was its chemical structure found to be?

13. In jest, we tell our students that when in doubt about which plant hormone causes which plant response, just answer auxin. Auxin has so many functions, this answer often works. List and describe four functions of auxin.

Auxin Functions Description

14. Did you catch the discussion of auxins as herbicides? Perhaps you have used Weed-B-Gone to kill dandelions in your lawn. Explain how this product kills dandelions without killing the

grass.

15. How did cytokinins get their name?

16. List and describe three functions of cytokinins.

Cytokinin Functions Description

17. Gibberellins occur naturally in plants, and like the previous two hormones, they have several effects. Describe three of them.

Gibberellin Functions Description




18. Abscisic acid (ABA) is misnamed. Why?

19. Describe three effects of abscisic acid.

Abscisic Acid Functions Description

20. Ethylene is the only hormone in our group that is a gas. Under what conditions is ethyleneproduced?

21. The effects of ethylene are many and varied. Describe them here.

Ethylene Functions Description

22. You have just finished a very complex look at plant hormones. Let’s try to summarize it by completing the following chart.

Hormone Action

leaf abscission




breaking seed dormancy

maintaining apical dominance

making internodes of grape bunches elongate to obtain larger fruit

gravitropism

drought tolerance

senescence

phototropism

cell elongation

increased cell division

Concept 39.3 Responses to light are critical for plant success

23. Researchers have determined that plants have two major classes of light receptors. List each class.

24. What wavelengths of light are absorbed by phytochromes?

25. What are three different responses initiated by blue light?

26. Read carefully the discussion of phytochromes and how they work. Pay attention to the two

types of red light. What is the wavelength of red light? Of far-red

light?




27. Phytochromes are photoreceptors that have two isomer forms, Pr and Pfr. Sketch the conversion of Pr to Pfr on this figure. Label all of the boxes, and also chromophore, phytochrome.

28. What is the active form of phytochrome, Pr or Pfr?

29. Look again at the effect of light exposure on lettuce seed germination. What determines the seed’s response?

30. To make sense of all this, you will want to read carefully the “Phytochromes and Shade Avoidance” section. Which type of red light is more common in a shaded area? Why?

31. What is a circadian rhythm? Give one plant example and one human example.

32. What is the photoperiod?

AP Biology Reading Guide Chapter 39: Plant Responses to Internal and External Signals



33. Plants detect photoperiod, and in many species it affects their time of flowering. Explain each of the following, and give an example of a plant that is in the group.

short-day plant

long-day plant

day-neutral plant

34. The plant in the sketch below is a short-day plant. Label R, FR, and critical dark period. For each line, explain why flowering occurs or does not occur.

35. What is florigen?

Concept 39.4 Plants respond to a wide variety of stimuli other than light

36. What is gravitropism? How may a plant detect gravity?

37. What is thigmotropism? How is it adaptive?

AP Biology Reading Guide Chapter 39: Plant Responses to Internal and External Signals



38. Describe an example of a rapid leaf movement. What do these action potentials resemble?

39. List six different ways in which a plant responds to water deficit.

40. Select any other stress situation besides water deficit, and explain plant mechanisms for dealing with this.

Concept 39.5 Plants respond to attacks by herbivores and pathogens

41. What are the two ways in which a plants combat excess herbivory?

42. Describe two examples of a plant producing chemicals to deal with herbivory.


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Chapter 35-39 Reading Guide Unit 6