Concept explainers
To discuss: The effect of Fusicoccin on the growth of “isolated stem sections”.
Concept introduction:
Stimulation of “plasma membrane proton (H+) pumps” of plant cells causes following changes:
- 1. Decreases the cell wall pH
- 2. Increases the membrane potential
- 1. Changes followed by “decrease in cell wall pH”:
Lowering pH raises acidity level on the cell wall which activates proteins called expansions. These expansions disrupt the hydrogen bonds. The bonds are found in between cell wall constituents and cellulose microfibrils. This loosens the cell wall.
- 2. Changes followed by “increase in membrane potential”:
Increased membrane potential promotes the ion transmission into the cell. This process initiates water absorption by osmosis. More amount of water simultaneously increases the turgor and which in turn increases the flexibility of cell wall. The increase in cell wall flexibility enables the elongation of the stem.
Want to see the full answer?
Check out a sample textbook solutionChapter 39 Solutions
Campbell Biology Plus Masteringbiology
- It is the term referring to the characteristic leaf structure of C4 plants that enables them to outperform C3 plants in an environment that has high O2 concentration and/or temperature. Unlike C3 and CAM plants, C4 plants, such as corn and sugarcane, have leaves with vascular bundles that are surrounded by a chloroplast-rich vascular bundle sheath, which is further surrounded by the spongy mesophyll.arrow_forwardWhat is false about the image below? A) The cells are part of plant ground tissue B) The cells are parenchyma cells. C) The cells provide flexible support. D) The cells would be a site of starch storage if they were in the roots 373arrow_forwardFungal reproduction: Provide name of structures in photo A and B and describe if the structure is involved in asexual or sexual reproduction Photo A below Photo B below 667 umarrow_forward
- Arrange the following subset of cell depreciation during plant growth ( in length ) in the correct sequence . 1) cell division in primary meristem . 2) cell division in apical meristem . 3) differentiated cells . 4) growing cells in primary meristem.arrow_forwardWhich of the following is not a way in which antifungaldrugs are effective?(a) They interfere with nucleic acid synthesis.(b) They increase plasma membrane permeability causingexcessive leakiness of essential substances.(c) They can impair the mitotic spindle apparatus.(d) They can induce mycorrhizae production.(e) None of the abovearrow_forwarddescribe the molecular switches involved during stationary growth phasearrow_forward
- Why do you think collechyma is not present in the root?arrow_forwardDifferentiate the colchicine-treated and untreated root tips cells in Allium cepaarrow_forwardIn a practice known as crop rotation, farmers alternate a crop of legumes (plants like beans, whose roots bear nodules containing Rhizobium) with a crop of non- legumes. What is the benefit of this practice?arrow_forward
- What is the movement of fungal hyphae towards sugar and peptones known as?arrow_forwardWhich of the following explains why pea plants in high soil nitrogen conditions have so few rhizobial nodules on their roots? When there is already high soil nitrogen there is a very large cost to having rhizobial nodules. The rhizobia bacteria in the nodules fix nitrogen when there isn't enough in the soil, so when there is already high soil nitrogen there is no advantage for the pea plant to expend the extra energy housing the rhizobia. The rhizobia bacteria in the nodules use nitrogen when there isn't enough in the soil, so in conditions of high soil nitrogen the plant tries to exclude the rhizobia to keep the nitrogen for itself. When there is already high soil nitrogen there is no benefit to the plant to having rhizobial nodules, which can rob the plant of the high nitrogen supplies so that the rhizobia bacteria do not have to fix the nitrogen themselves.arrow_forward7. a)Tea plants contain several chemical compounds, including tannins and caffeine. What function do both tannins and caffeine perform for tea leaves? b)By what process does water enter the root cells of a plant? c)The blade of the leaf is attached to the stem by a stoma. Is this true or false?arrow_forward
- Biology (MindTap Course List)BiologyISBN:9781337392938Author:Eldra Solomon, Charles Martin, Diana W. Martin, Linda R. BergPublisher:Cengage LearningBiology: The Dynamic Science (MindTap Course List)BiologyISBN:9781305389892Author:Peter J. Russell, Paul E. Hertz, Beverly McMillanPublisher:Cengage Learning