1. PLANT STRUCTURE AND FUNCTION
PLANT STRUCTURE AND FUNCTION
Copyright © 2009 Pearson Education, Inc.

2. Evolution and types of plants
Since the earth was once covered in water, plants had to make three adaptations to survive on land
The ability to prevent water loss
The ability to reproduce in the absence of water
The ability to absorb and transport nutrients
Plants can be placed under two groups
Vascular- having true roots, leaves, and stems
Ex. ferns, conifers, flowering plants
Nonvascular- not having true roots, leaves, and stems
Ex. mosses, liverworts, hornworts

3. Vascular Plants can be divided into two groups
Seedless Plants
Seed Plants
Made up of ferns and plants closely associated with ferns
Two types of seed plants
Gymnosperms- which includes pine trees, produce seeds that are not encased in fruit
Angiosperms- aka flowering plants, produce seeds within a protective fruit

4. The two main groups of angiosperms are the monocots and the dicots
Monocots
One cotyledon
Parallel leaf venation
Scattered vascular bundles
Flower parts in 3s or multiples of 3
Fibrous roots
Student Misconceptions and Concerns
1. Students often fail to see the specific applications of fundamental principles of biology. For example, many structural adaptations increase the surface-to-volume ratio in plants and animals. The divisions within the human lung, as well as microvilli, leaves, and root hairs, are examples. Increased surface areas are typically found where something is exchanged: gases exchanged at respiratory surfaces, nutrients absorbed by microvilli, light absorbed by leaves, and water and minerals absorbed by root hairs. If this chapter is one of the final topics addressed in your course, illustrating these broad principles with examples from a variety of subjects can serve as a unifying review.
Teaching Tips
1. Figure 31.2 provides a visually simple but important comparison of monocots and eudicots. By referring to this figure in class, students will be able to absorb more details during lecture that they can then review at their leisure.
2. Consider bringing living examples of monocots and eudicots to class or taking a short trip outside during a related lab to quickly compare examples.

5. The two main groups of angiosperms are the monocots and the eudicots
Dicots- aka eudicots
Two cotyledons
Branched leaf venation
Ring of vascular bundles
Flower parts in 4s or 5s (or multiples)
Taproot system
Student Misconceptions and Concerns
1. Students often fail to see the specific applications of fundamental principles of biology. For example, many structural adaptations increase the surface-to-volume ratio in plants and animals. The divisions within the human lung, as well as microvilli, leaves, and root hairs, are examples. Increased surface areas are typically found where something is exchanged: gases exchanged at respiratory surfaces, nutrients absorbed by microvilli, light absorbed by leaves, and water and minerals absorbed by root hairs. If this chapter is one of the final topics addressed in your course, illustrating these broad principles with examples from a variety of subjects can serve as a unifying review.
Teaching Tips
1. Figure 31.2 provides a visually simple but important comparison of monocots and eudicots. By referring to this figure in class, students will be able to absorb more details during lecture that they can then review at their leisure.
2. Consider bringing living examples of monocots and eudicots to class or taking a short trip outside during a related lab to quickly compare examples.

6. A typical plant body contains three basic organs: roots, stems, and leaves
Plants absorb water and minerals from soil through roots
Plants absorb the sun’s energy and carbon dioxide from the air through shoots (stems and leaves)
Plant roots depend on shoots for carbohydrates produced via photosynthesis
Plant shoots depend on roots for water and minerals
Teaching Tips
1. Challenge your students to suggest circumstances when apical growth is more adaptive for a plant, and other situations in which branching would be more favorable.
Copyright © 2009 Pearson Education, Inc.

7. A typical plant body contains three basic organs: roots, stems, and leaves
Plant roots
Anchor plant
Absorb water and nutrients
Store food
Plant shoots
Stems, leaves, and reproductive structures
Stems provide support
Leaves carry out photosynthesis
Teaching Tips
1. Challenge your students to suggest circumstances when apical growth is more adaptive for a plant, and other situations in which branching would be more favorable.
Copyright © 2009 Pearson Education, Inc.

8. Terminal bud Blade Leaf Flower Petiole Axillary bud Stem Shoot system
Node
Internode
Root
hair
Root
hairs
Figure 31.3 The body plan of a flowering plant (a eudicot).
Taproot
Root
system
Epidermal cell

9. Many plants have modified roots, stems, and leaves
Modifications of plant parts are adaptations for various functions
Food or water storage
Asexual reproduction
Protection
Climbing
Photosynthesis
Teaching Tips
1. The modifications of the three plant organs described in Module 31.4 reveal the remodeling nature of evolution. As Francois Jacob noted, evolution works more like a tinkerer than an engineer. The common ancestry of eudicots is revealed by the diverse modifications of three basic plant organs derived from the shared ancestors. Your students’ appreciation of the enormous evidence in support of evolution will grow if you note such examples frequently throughout your course.
Copyright © 2009 Pearson Education, Inc.

10. Many plants have modified roots, stems, and leaves
Root modifications
Food storage
Examples include carrots & potatoes
Teaching Tips
1. The modifications of the three plant organs described in Module 31.4 reveal the remodeling nature of evolution. As Francois Jacob noted, evolution works more like a tinkerer than an engineer. The common ancestry of eudicots is revealed by the diverse modifications of three basic plant organs derived from the shared ancestors. Your students’ appreciation of the enormous evidence in support of evolution will grow if you note such examples frequently throughout your course.

11. Many plants have modified roots, stems, and leaves
Stem modifications
Runners (allow for asexual reproduction)
Teaching Tips
1. The modifications of the three plant organs described in Module 31.4 reveal the remodeling nature of evolution. As Francois Jacob noted, evolution works more like a tinkerer than an engineer. The common ancestry of eudicots is revealed by the diverse modifications of three basic plant organs derived from the shared ancestors. Your students’ appreciation of the enormous evidence in support of evolution will grow if you note such examples frequently throughout your course.

12. Many plants have modified roots, stems, and leaves
Leaf modifications
Climbing
tendril
Example: pea plants
Protection
Thorns or spines
Example: Cactus spine
Teaching Tips
1. The modifications of the three plant organs described in Module 31.4 reveal the remodeling nature of evolution. As Francois Jacob noted, evolution works more like a tinkerer than an engineer. The common ancestry of eudicots is revealed by the diverse modifications of three basic plant organs derived from the shared ancestors. Your students’ appreciation of the enormous evidence in support of evolution will grow if you note such examples frequently throughout your course.

13. Plant cells and tissues are diverse in structure and function
Plants cells have three structures that distinguish them from animals cells
Chloroplasts used in photosynthesis
A large, fluid-filled vacuole
A cell wall composed
of cellulose
Student Misconceptions and Concerns
1. Students may not understand turgor, although they encounter it in their lives. The shape of a water balloon is different from the shape of an uninflated balloon due to internal fluid pressure (turgor). A plant in need of water may have drooping leaves, a consequence of decreased turgor.
Teaching Tips
1. Cellulose is the most abundant organic compound on Earth. Students often find this fact worth remembering.
2. Students will remember the function of phloem more easily if you remind them that both phloem and food start with an “F” sound.
For the BioFlix Animation Tour of a Plant Cell, go to Animation and Video Files.

14. PLANT GROWTH
Copyright © 2009 Pearson Education, Inc.

15. Primary growth Plants are categorized based on how long they live
Plants are categorized based on how long they live
Annuals complete their life cycle in one year
Biennials complete their life cycle in two years
Perennials live for many years
Student Misconceptions and Concerns
1. Students often expect determinate growth in plants, because it is characteristic of humans. However, most plant species show indeterminate growth and are capable of growing as long as they can live.
Teaching Tips
1. Lobsters are one of the few animals that show indeterminate growth.
Copyright © 2009 Pearson Education, Inc.

16. Primary growth allows roots to push downward through the
soil and shoots to grow upward
Terminal bud
Axillary buds
Figure 31.7A Locations of apical meristems, which are responsible for primary growth.
Arrows =
direction
of growth
Root
tips

17. Secondary growth increases the girth of woody plants
Year 1
Early Spring
Year 2
Late Summer
Year 1
Late Summer
Figure 31.8A Secondary growth of a woody eudicot stem.

18. Secondary growth increases the girth of woody plants
Cork cambium produces the outer bark
Student Misconceptions and Concerns
1. Students typically expect that as a tree grows taller, the trunk will “stretch” upward along its entire length. This expectation arises naturally from the experience of our own growth as humans. However, as a tree grows, the entire trunk does not increase in size. Instead, growth occurs at the upper ends and through expansion of the trunk. Therefore, initials carved into the trunk of a tree will remain at that height as long as the tree is upright and healthy.
Teaching Tips
1. Students may not realize that the cork used to seal a wine bottle is the same cork that is discussed in Module 31.8.
2. Students may not appreciate the many important functions of tree bark. Carving into bark, or peeling it away from a trunk, exposes the inner tissues to pathogens. In many ways, the functions of human skin and bark are similar.
Copyright © 2009 Pearson Education, Inc.

19. Secondary growth increases the girth of woody plants
Wood annual rings show when new growth starts each year.
Sapwood (transport)- functional, lighter-colored wood near the outside of the trunk
Heartwood (storage)- the darker wood at the center of the trunk
Student Misconceptions and Concerns
1. Students typically expect that as a tree grows taller, the trunk will “stretch” upward along its entire length. This expectation arises naturally from the experience of our own growth as humans. However, as a tree grows, the entire trunk does not increase in size. Instead, growth occurs at the upper ends and through expansion of the trunk. Therefore, initials carved into the trunk of a tree will remain at that height as long as the tree is upright and healthy.
Teaching Tips
1. Students may not realize that the cork used to seal a wine bottle is the same cork that is discussed in Module 31.8.
2. Students may not appreciate the many important functions of tree bark. Carving into bark, or peeling it away from a trunk, exposes the inner tissues to pathogens. In many ways, the functions of human skin and bark are similar.

20. Secondary growth increases the girth of woody plants
Xylem- transports water
Phloem- transports food
Student Misconceptions and Concerns
1. Students typically expect that as a tree grows taller, the trunk will “stretch” upward along its entire length. This expectation arises naturally from the experience of our own growth as humans. However, as a tree grows, the entire trunk does not increase in size. Instead, growth occurs at the upper ends and through expansion of the trunk. Therefore, initials carved into the trunk of a tree will remain at that height as long as the tree is upright and healthy.
Teaching Tips
1. Students may not realize that the cork used to seal a wine bottle is the same cork that is discussed in Module 31.8.
2. Students may not appreciate the many important functions of tree bark. Carving into bark, or peeling it away from a trunk, exposes the inner tissues to pathogens. In many ways, the functions of human skin and bark are similar.