38 39

Chapter 38: 

Chapter 38 Angiosperm Reproduction and Biotechnology

Figure 38.1 Rafflesia arnoldii, “monster flower” of Indonesia: 

Figure 38.1 Rafflesia arnoldii, “monster flower” of Indonesia

Figure 38.2 An overview of angiosperm reproduction: 

Figure 38.2 An overview of angiosperm reproduction

Figure 38.3 Floral Variations : 

Figure 38.3 Floral Variations

Figure 38.4 The development of angiosperm gametophytes (pollen grains and embryo sacs): 

Figure 38.4 The development of angiosperm gametophytes (pollen grains and embryo sacs)

Figure 38.5 “Pin” and “thrum” flower types reduce self-fertilization: 

Figure 38.5 “Pin” and “thrum” flower types reduce self-fertilization

Figure 38.6 Growth of the pollen tube and double fertilization: 

Figure 38.6 Growth of the pollen tube and double fertilization

Figure 38.7 The development of a eudicot plant embryo: 

Figure 38.7 The development of a eudicot plant embryo Suspensor Suspensor

Figure 38.8 Seed structure: 

Figure 38.8 Seed structure

Figure 38.9 Developmental origin of fruits: 

Figure 38.9 Developmental origin of fruits

Figure 38.10 Two common types of seed germination: 

Figure 38.10 Two common types of seed germination

Figure 38.11 Asexual reproduction in aspen trees: 

Figure 38.11 Asexual reproduction in aspen trees

Figure 38.12 Test-tube cloning of carrots: 

Figure 38.12 Test-tube cloning of carrots

Figure 38.13 Protoplasts: 

Figure 38.13 Protoplasts 50 m

Figure 38.14 Maize: a product of artificial selection: 

Figure 38.14 Maize: a product of artificial selection

Figure 38.15 Genetically engineered papaya: 

Figure 38.15 Genetically engineered papaya

Figure 38.16 Grains of “Golden Rice” interspersed with grains of ordinary rice: 

Figure 38.16 Grains of “Golden Rice” interspersed with grains of ordinary rice Ordinary rice Genetically modified rice

Chapter 39: 

Chapter 39 Plant Responses to Internal and External Signals

Figure 39.1 Grass seedling growing toward light: 

Figure 39.1 Grass seedling growing toward light

Figure 39.2 Light-induced de-etiolation (greening) of dark-grown potatoes: 

Figure 39.2 Light-induced de-etiolation (greening) of dark-grown potatoes (a) Before exposure to light. A dark-grown potato has tall, spindly stems and nonexpanded leaves—morphological adaptations that enable the shoots to penetrate the soil. The roots are short, but there is little need for water absorption because little water is lost by the shoots. (b) After a week’s exposure to natural daylight. The potato plant begins to resemble a typical plant with broad green leaves, short sturdy stems, and long roots. This transformation begins with the reception of light by a specific pigment, phytochrome.

Figure 39.3 Review of a general model for signal transduction pathways: 

Figure 39.3 Review of a general model for signal transduction pathways

Figure 39.4 An example of signal transduction in plants: the role of phytochrome in the de-etiolation (greening) response (layer 3): 

Figure 39.4 An example of signal transduction in plants: the role of phytochrome in the de-etiolation (greening) response (layer 3)

Figure 39.5 What part of a coleoptile senses light, and how is the signal transmitted?: 

Figure 39.5 What part of a coleoptile senses light, and how is the signal transmitted?

Figure 39.6 Does asymmetric distribution of a growth-promoting chemical cause a coleoptile to grow toward the light?: 

Figure 39.6 Does asymmetric distribution of a growth-promoting chemical cause a coleoptile to grow toward the light? EXPERIMENT

Table 39.1 An Overview of Plant Hormones: 

Table 39.1 An Overview of Plant Hormones

Figure 39.7 What causes polar movement of auxin from shoot tip to base?: 

Figure 39.7 What causes polar movement of auxin from shoot tip to base? To investigate how auxin is transported unidirectionally, researchers designed an experiment to identify the location of the auxin transport protein. They used a greenish-yellow fluorescent molecule to label antibodies that bind to the auxin transport protein. They applied the antibodies to longitudinally sectioned Arabidopsis stems. RESULTS The left micrograph shows that the auxin transport protein is not found in all tissues of the stem, but only in the xylem parenchyma. In the right micrograph, a higher magnification reveals that the auxin transport protein is primarily localized to the basal end of the cells. CONCLUSION The results support the hypothesis that concentration of the auxin transport protein at the basal ends of cells is responsible for polar transport of auxin. EXPERIMENT

Figure 39.8 Cell elongation in response to auxin: the acid growth hypothesis: 

Figure 39.8 Cell elongation in response to auxin: the acid growth hypothesis

Figure 39.9 Apical dominance: 

Figure 39.9 Apical dominance

Figure 39.10 The effect of gibberellin treatment on Thompson seedless grapes: 

Figure 39.10 The effect of gibberellin treatment on Thompson seedless grapes

Figure 39.11 Gibberellins mobilize nutrients during the germination of grain seeds: 

Figure 39.11 Gibberellins mobilize nutrients during the germination of grain seeds 2

Figure 39.12 Precocious germination of mutant maize seeds: 

Figure 39.12 Precocious germination of mutant maize seeds

Figure 39.13 How does ethylene concentration affect the triple response in seedlings?: 

Figure 39.13 How does ethylene concentration affect the triple response in seedlings?

Figure 39.14 Ethylene triple-response Arabidopsis mutants: 

Figure 39.14 Ethylene triple-response Arabidopsis mutants (a) ein mutant. An ethylene-insensitive (ein) mutant fails to undergo the triple response in the presence of ethylene. (b) ctr mutant. A constitutive triple-response (ctr) mutant undergoes the triple response even in the absence of ethylene. ein mutant ctr mutant

Figure 39.15 Ethylene signal transduction mutants can be distinguished by their different responses to experimental treatments: 

Figure 39.15 Ethylene signal transduction mutants can be distinguished by their different responses to experimental treatments

Figure 39.16 Abscission of a maple leaf: 

Figure 39.16 Abscission of a maple leaf

Figure 39.17 What wavelengths stimulate phototropic bending toward light?: 

Figure 39.17 What wavelengths stimulate phototropic bending toward light? Researchers exposed maize (Zea mays) coleoptiles to violet, blue, green, yellow, orange, and red light to test which wavelengths stimulate the phototropic bending toward light. EXPERIMENT The graph below shows phototropic effectiveness (curvature per photon) relative to effectiveness of light with a wavelength of 436 nm. The photo collages show coleoptiles before and after 90-minute exposure to side lighting of the indicated colors. Pronounced curvature occurred only with wavelengths below 500 nm and was greatest with blue light. RESULTS CONCLUSION The phototropic bending toward light is caused by a photoreceptor that is sensitive to blue and violet light, particularly blue light.

Figure 39.18 How does the order of red and far-red illumination affect seed germination?: 

Figure 39.18 How does the order of red and far-red illumination affect seed germination? CONCLUSION EXPERIMENT RESULTS During the 1930s, USDA scientists briefly exposed batches of lettuce seeds to red light or far-red light to test the effects on germination. After the light exposure, the seeds were placed in the dark, and the results were compared with control seeds that were not exposed to light. The bar below each photo indicates the sequence of red-light exposure, far-red light exposure, and darkness. The germination rate increased greatly in groups of seeds that were last exposed to red light (left). Germination was inhibited in groups of seeds that were last exposed to far-red light (right). Red light stimulated germination, and far-red light inhibited germination. The final exposure was the determining factor. The effects of red and far-red light were reversible.

Figure 39.19 Structure of a phytochrome: 

Figure 39.19 Structure of a phytochrome

Unnumbered figure page 804: 

Unnumbered figure page 804

Figure 39.20 Phytochrome: a molecular switching mechanism : 

Figure 39.20 Phytochrome: a molecular switching mechanism Far-red light Red light Slow conversion in darkness (some plants) Responses: seed germination, control of flowering, etc. Enzymatic destruction Pfr Pr

Figure 39.21 Sleep movements of a bean plant (Phaseolus vulgaris): 

Figure 39.21 Sleep movements of a bean plant (Phaseolus vulgaris)

Figure 39.22 How does interrupting the dark period with a brief exposure to light affect flowering?: 

Figure 39.22 How does interrupting the dark period with a brief exposure to light affect flowering?

Figure 39.23 Is phytochrome the pigment that measures the interruption of dark periods in photoperiodic response?: 

Figure 39.23 Is phytochrome the pigment that measures the interruption of dark periods in photoperiodic response?

Figure 39.24 Is there a flowering hormone?: 

Figure 39.24 Is there a flowering hormone?

Figure 39.25 Positive gravitropism in roots: the statolith hypothesis: 

Figure 39.25 Positive gravitropism in roots: the statolith hypothesis

Figure 39.26 Altering gene expression by touch in Arabidopsis: 

Figure 39.26 Altering gene expression by touch in Arabidopsis

Figure 39.27 Rapid turgor movements by the sensitive plant (Mimosa pudica): 

Figure 39.27 Rapid turgor movements by the sensitive plant (Mimosa pudica)

Figure 39.28 A developmental response of maize roots to flooding and oxygen deprivation: 

Figure 39.28 A developmental response of maize roots to flooding and oxygen deprivation

Figure 39.29 A maize leaf “recruits” a parasitoid wasp as a defensive response to an herbivore, an army-worm caterpillar: 

Figure 39.29 A maize leaf “recruits” a parasitoid wasp as a defensive response to an herbivore, an army-worm caterpillar

Figure 39.30 Gene-for-gene resistance of plants to pathogens: the receptor-ligand model: 

Figure 39.30 Gene-for-gene resistance of plants to pathogens: the receptor-ligand model

Figure 39.31 Defense responses against an avirulent pathogen: 

Figure 39.31 Defense responses against an avirulent pathogen