CHAPTER 35
PLANT STRUCTURE, GROWTH, AND DEVELOPMENT
Learning objectives
The Plant Body
- Describe and compare the three basic organs of vascular plants. Explain how these basic organs are interdependent.
- List the basic functions of roots. Describe and compare the structures and functions of fibrous roots, taproots, root hairs, and adventitious roots.
- Describe the basic structure of plant stems.
- Explain the phenomenon of apical dominance.
- Describe and distinguish between the leaves of monocots and eudicots.
- Describe the three tissue systems that make up plant organs.
- Describe and distinguish between the three basic cell types of plant tissues. For each tissue, describe one characteristic structural feature and explain its functional significance.
- Explain the functional relationship between a sieve-tube member and its companion cell.
The Process of Plant Growth and Development
- Distinguish between determinate and indeterminate growth. Give an example of each type of growth.
- Distinguish between annual, biennial, and perennial plants.
- Explain this statement: “In contrast to most animals, which have a stage of embryonic growth, plants have regions of embryonic growth.”
- Distinguish between the primary and secondary plant body.
- Describe in detail the primary growth of the tissues of roots and shoots.
- Describe in detail the secondary growth of the tissues of roots and shoots.
- Name the cells that make up the tissue known as wood. Name the tissues that comprise the bark.
Mechanisms of Plant Growth and Development
- Explain why Arabidopsis is an excellent model for the study of plant development.
- Explain what each of these Arabidopsis mutants have taught us about plant development:
- fass mutant
- gnom mutant
- KNOTTED-1 mutant
- GLABRA-2 mutant
- Define and distinguish between morphogenesis, differentiation, and growth.
- Explain why (a) the plane and symmetry of cell division, (b) the orientation of cell expansion, and (c) cytoplasmic microtubules are important determinants of plant growth and development.
- Explain how pattern formation may be determined in plants.
- Give an example to demonstrate how a cell’s location influences its developmental fate.
- Explain how a vegetative shoot tip changes into a floral meristem.
- Describe how three classes of organ identity genes interact to produce the spatial pattern of floral organs inArabidopsis.
CHAPTER 36
RESOURCE ACQUISITION AND TRANSPORT IN VASCULAR PLANTS
Learning objectives:
Resource Acquisition by Land Plants
- Explain how variation in shoot morphology may enhance light capture by plants in specific environments.
- Explain how mycorrhizae enhance uptake of materials by roots.
- Describe the evidence for recognition of “non-self” by buffalo grass stolons. Explain the benefit of such recognition.
General Principles of Transport in Plants
- Describe how proton pumps function in transport of materials across plant membranes, using the terms ‘proton gradient’, ‘membrane potential’, and ‘cotransport’.
- Define osmosis and water potential. Explain how water potential is measured.
- Explain how solutes and pressure affect water potential.
- Explain how the physical properties of plant cells are changed when the plant is placed into solutions that have higher, lower, or the same solute concentration.
- Define the terms flaccid, plasmolyze, turgor pressure, and turgid.
- Explain how aquaporins affect the rate of water transport across membranes.
- Distinguish between the symplast and the apoplast.
- Describe three routes available for short-distance transport in plants.
- Define bulk flow and describe the forces that generate pressure in the vascular tissue of plants.
- Relate the structure of sieve-tube cells, vessel cells, and tracheids to their functions in bulk flow.
Absorption of Water and Minerals by Roots
- Explain what routes are available to water and minerals moving into the vascular cylinder of the root.
- Explain how the endodermis functions as a selective barrier between the root cortex and vascular cylinder.
Transport of Xylem Sap
- Describe the potential and limits of root pressure to move xylem sap.
- Define the terms transpiration and guttation.
- Explain how transpirational pull moves xylem sap up from the root tips to the leaves.
- Explain how cavitation prevents the transport of water through xylem vessels.
- Explain this statement: “The ascent of xylem sap is ultimately solar powered.”
The Control of Transpiration
- Explain the importance and costs of the broad external surface area and extensive inner surface area of many leaves.
- Discuss the factors that may alter the stomatal density of a leaf.
- Describe the role of guard cells in photosynthesis-transpiration.
- Explain how and when stomata open and close.
- Describe the cues that trigger stomatal opening at dawn.
- Explain how xerophytes reduce transpiration.
- Explain why crassulacean acid metabolism is an important adaptation to reduce transpiration in arid environments.
Translocation of Phloem Sap
- Define and describe the process of translocation. Trace the path of phloem sap from a primary sugar source to a sugar sink.
- Describe the process of sugar loading and unloading.
- Define pressure flow. Explain the significance of this process in angiosperms.
The Dynamic Symplasm
- Describe how and why plasmodesmata may change in function, number, and pore size.
- Describe the roles of phloem in electrical signaling and systemic transport.
CHAPTER 37
SOIL AND PLANT NUTRITION
Learning objectives:
The Role of Soil in Plant Nutrition
- Define soil texture and soil composition.
- Explain how soil is formed.
- Name the components of topsoil.
- Describe the composition of loams and explain why they are the most fertile soils.
- Explain how humus contributes to the texture and composition of soils.
- Explain why plants cannot extract all of the water in soil.
- Explain how the presence of clay in soil helps prevent the leaching of mineral cations.
- Define cation exchange, explain why it is necessary for plant nutrition, and describe how plants can stimulate the process.
- Explain why soil conservation is necessary in agricultural systems but not in natural ecosystems. Describe an example of human mismanagement of soil.
- Explain how soil pH determines the effectiveness of fertilizers and a plant’s ability to absorb specific mineral nutrients.
- Describe problems resulting from farm irrigation in arid regions.
- Describe actions that can reduce loss of topsoil due to erosion.
- Explain how phytoremediation can help detoxify polluted soil.
Nutritional Requirements of Plants
- Describe the ecological role of plants in transforming inorganic molecules into organic compounds.
- Define the term ‘essential nutrient’.
- Explain how hydroponic culture is used to determine which minerals are essential nutrients.
- Distinguish between macronutrient and micronutrient.
- Name the nine macronutrients required by plants.
- List the eight micronutrients required by plants and explain why plants need only minute quantities of these elements.
- Explain how a nutrient’s role and mobility determine the symptoms of a mineral deficiency.
- Describe an example of a genetically modified plant tailored to do well in particular soil conditions.
Plants and Rhizobacteria
- Define the term rhizosphere.
- Explain how plant-growth-enhancing rhizobacteria act to enhance plant growth.
- Summarize the ecological role of each of the following groups of bacteria.
- ammonifying bacteria
- denitrifying bacteria
- nitrogen-fixing bacteria
- nitrifying bacteria
- Define nitrogen fixation and write an overall equation representing the conversion of gaseous nitrogen to ammonia.
- Describe the development of a root nodule in a legume.
- Explain how a legume protects its nitrogen-fixing bacteria from free oxygen, and explain why this protection is necessary.
- Describe the basis for crop rotation.
- Explain why a symbiosis between a legume and its nitrogen-fixing bacteria is considered to be mutualistic.
- Explain why a symbiosis between a plant and a mycorrhizal fungus is considered to be mutualistic.
- Distinguish between ectomycorrhizae and arbuscular mycorrhizae.
Plant Parasites, Epiphytes, and Predators
- Name one modification for nutrition in each of the following groups of plants:
- parasitic plants
- epiphytes
- carnivorous plants
CHAPTER 38
ANGIOSPERM REPRODUCTION AND BIOTECHNOLOGY
Learning objectives:
The Three Fs: Flowers, Double Fertilization, and Fruits
- In general terms, explain how the basic plant life cycle with alternation of generations is modified in angiosperms.
- List four floral parts in order from outside to inside a flower.
- From a diagram of an complete flower, correctly label the following structures and describe the function of each structure:
- Sepal
- Petals
- Stamen (filament and anther)
- Carpel (style, ovary, ovule, and stigma)
- Distinguish between:
- Complete and incomplete flowers
- Bisexual and unisexual flowers
- Microspores and megaspores
- Explain by which generation, structure, and process spores are produced.
- Explain by which generation, structure, and process gametes are produced.
- Describe the production and structure of the male gametophyte of a flowering plant.
- Describe the development of an embryo sac and explain the fate of each of its cells.
- Explain how pollen can be transferred between flowers.
- Distinguish between pollination and fertilization.
- Outline the process of double fertilization. Explain the adaptive advantage of double fertilization in angiosperms.
- Describe the fate of the ovule and ovary after double fertilization. Note where major nutrients are stored as the embryo develops.
- Describe the development and function of the endosperm. Distinguish between liquid endosperm and solid endosperm.
- Describe the development of a plant embryo from the first mitotic division to the embryonic plant with rudimentary organs.
- From a diagram, identify the following structures of a seed and state a function for each:
- Seed coat
- Proembryo
- Suspensor
- Hypocotyl
- Radicle
- Epicotyl
- Plumule
- Endosperm
- Cotyledon
- Explain how a monocot and dicot seed differ.
- Explain how seed dormancy can be advantageous to a plant. Describe some conditions for breaking dormancy.
- Explain how fruit forms and ripens.
- Distinguish between simple, aggregate, multiple, and accessory fruit. Give an example of each type of fruit.
- Describe the process of germination in a garden bean and corn plant.
Sexual and Asexual Reproduction in Plants
- Describe the natural mechanisms of vegetative reproduction in plants, including fragmentation and apomixis.
- Explain the advantages and disadvantages of reproducing sexually and asexually.
- Describe mechanisms that prevent self-pollination.
- Explain various methods that horticulturalists use to propagate plants from cuttings.
- Explain how the technique of plant tissue culture can be used to clone and genetically engineer plants.
- Describe the process of protoplast fusion and its potential agricultural impact.
Plant Biotechnology
- Compare traditional plant-breeding techniques and genetic engineering, noting similarities and differences.
- Describe two transgenic crops.
- Explain the benefits of introducing genes for Bt toxin into crop plants.
- Describe arguments for and against the development and use of biofuels.
- Explain the circumstances in which crop-to-weed trangene escape could occur. Describe four strategies that may prevent transgene escape.
CHAPTER 39
PLANT RESPONSES TO
INTERNAL AND EXTERNAL SIGNALS
Learning objectives:
Signal Transduction and Plant Responses
- Compare the growth of a plant in darkness (etiolation) to the characteristics of greening (de-etiolation).
- Describe the signal pathways associated with de-etiolation.
- Describe the role of second messengers in the process of de-etiolation.
- Describe the two main mechanisms by which a signaling pathway can activate an enzyme.
- Explain, with examples, what researchers have learned about the activity of plant hormones by study of mutant plants.
Plant Responses to Hormones
- Compare plant and animal responses to hormones.
- For the following scientists, describe their hypothesis, experiments, and conclusions about the mechanism of phototropism:
- Charles and Francis Darwin
- Peter Boysen-Jensen
- Frits Went
- List six classes of plant hormones, describe their major functions, and note where they are produced in the plant.
- Explain how a hormone may cause its effect on plant growth and development.
- Describe a possible mechanism for the polar transport of auxin.
- According to the acid-growth hypothesis, explain how auxin can initiate cell elongation.
- Explain why 2,4-D is widely used as a weed killer.
- Explain how the ratio of cytokinin to auxin affects cell division and cell differentiation.
- Describe the evidence that suggests factors other than auxin from the terminal bud may control apical dominance.
- Describe how auxin and gibberellins work together to stimulate stem elongation.
- Explain the role of gibberellins in triggering seed germination.
- Describe the functions of brassinosteroids in plants.
- Describe the effects of ABA on seed dormancy and drought stress.
- Describe the role of ethylene in the triple response to mechanical stress, apoptosis, leaf abscission, and fruit ripening.
Plant Responses to Light
- Define photomorphogenesis and note which colors are most important in regulating this process.
- Compare the roles of blue-light photoreceptors and phytochromes.
- Describe the phenomenon of chromophore photoreversibility and explain its role in light-induced germination of lettuce seeds.
- Define circadian rhythm and explain what happens when an organism is artificially maintained in a constant environment.
- Explain how light entrains biological clocks.
- Define photoperiodism.
- Distinguish between short-day, long-day, and day-neutral plants. Explain why these names are misleading.
- Explain what factors other than night length may control flowering.
- Describe the evidence that the CONSTANS gene plays a role in signaling flowering.
Plant Responses to Other Environmental Stimuli
- Describe how plants apparently tell up from down. Explain why roots display positive gravitropism and shoots exhibit negative gravitropism.
- Distinguish between thigmotropism and thigmomorphogenesis.
- Describe how motor organs can cause rapid leaf movements.
- Provide a plausible explanation for how a stimulus causing rapid leaf movement can be transmitted through the plant.
- Describe the challenges posed by, and the responses of plants to, the following environmental stresses: drought, flooding, salt stress, heat stress, and cold stress.
Plant Defenses Against Herbivores and Pathogens
- Explain how plants deter herbivores with physical and chemical defenses.
- Describe how plants may recruit parasitoids to attack herbivorous caterpillars.
- Describe how the hypersensitive response helps a plant limit the damage from pathogen attack.
- Explain the role of salicylic acid in eliciting systemic acquired resistance to infection.
Learning Objectives for Campbell/Reece Biology, 8th Edition, © Pearson Education, Inc.1 of 1