Concept explainers
a.
To determine: What is signal and receptor.
Introduction: A process through which the plants convert their plastids and etioplast that are present inside its chloroplast is known as de-etiolation. The plants that have undergone etiolation process would be growing in complete darkness and are generally thin, long and whilte in color.
a.
Explanation of Solution
In the process of de-etiolation, signal is light and the receptor is a phytochrome, a blue pigment that is present in the cytosol.
b.
To determine: The important steps that are involved in the process of transduction of the signal.
Introduction: A process through which the plants convert their plastids and etioplast that are present inside its chloroplast is known as de-etiolation. The plants that have undergone etiolation process would be growing in complete darkness and are generally thin, long and whilte in color.
b.
Explanation of Solution
The phytochrome pigment is activated by light. This activated phytochrome triggers atleast two signal pathways. One pathway results in the production of cGMP (cyclic guanosine monophosphate). The other pathway results in the increase of cytosolic calcium or Ca2+ levels. Both the pathways activate specific kinases enzymes. Some of them might activates several transcription factors that change the expression of genes.
c.
To determine: What is the growth response of plants and proteins involved in the plant’s growth response.
Introduction: Light is significant for the growth of the plants, however, it is essential to direct the growth as well as the development of plants. Sunlight serves as the signal to initiate and regulate the process of photomorphogenesis and photoperiodism. The two-light systems that play a major in the growth responses are the red light sensitive system and the blue light sensitive system.
c.
Explanation of Solution
The growth response of a plant is generally dependent on the stimulus or light. Changes in the plant such as the expansion of leaves, elongation of roots as well as the slowing of stem part elongation are collectively known as the growth response of the plants. In the de-etiolation process, levels of growth-regulating hormones are altered and the production of new enzymes is activated. This activation leads to the production of chlorophyll or the photosynthesis process.
The proteins that are involved in the growth responses are auxin (protein for expansion), cytokinin (protein for mitosis), and cytokin (protein for apoptosis).
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Chapter 39 Solutions
Study Guide for Campbell Biology
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- What is cell signaling? What is cell communication? Why are the cell signaling and cell communication essential for the plant growth and response? What is signal transduction?arrow_forwardWhat is the first messenger in signal transduction? What are second messengers in signal transduction? What are the three results of signal transduction? What are three types of signaling processes based on their transduction distance? Give an example for each type. What are the signaling molecules in the plant? Please describe each of them briefly. How phytohormone degradation plays important roles in signaling pathways? Explain one of the phytohormones as an example. How plants respond to the environmental stimuli (biotic and abiotic stresses)? Please explain the amechanism and give an example.arrow_forwardIt was observed during the early 20th century that the abscission zone of leaves of tree growing close to gas burning street lamps weakened (entered the abscission phase) earlier than trees located further away from the lamps. Experiments showed that weakening of the abscission zone was not caused by either the lamp's light or heat. Instead the research on this phenomenon led to the discovery of a new gaseous plant hormone. What is this hormone? Ethylene Abscisic acid (ABA) Gibberellins Auxin Strigolactone Cytokininarrow_forward
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