Why do many plants become bushier if you pinch off their terminal buds?

Certain fungi cause diseases in plants. There are a variety of antifungal sprays that can be used to control this problem. Some gardeners constantly spray their plants with fungicides, even when no signs of disease are evident. How might this be disadvantageous to the plant?

Which of the following activities of soil bacteria does not contribute to creating a form of nitrogen that plants can use? a. the fixation of atmospheric nitrogen b. the conversion of ammonium to nitrate c. the assembly of amino acids into proteins d. the generation of ammonium from proteins in dead leaves

Plants transport two types of sap. __________ sap, a solution of mostly water and sucrose, is transported from sites of sugar production to other parts of the plant. __________ sap, a solution of mostly water and inorganic ions, is transported from the roots to the rest of the plant body

Contrast cohesion and adhesion, and describe the role of each in the ascent of xylem sap.

Auxins cause a shoot to bend toward light by a. causing cells to shrink on the dark side of the shoot. b. stimulating growth on the dark side of the shoot. c. causing cells to shrink on the lighted side of the shoot. d. stimulating growth on the lighted side of the shoot.

The status of axillary budsdormant or growingdepends on the relative concentrations of __________ moving down from the shoot tip and __________ moving up from the roots.

Why do many plants become bushier if you pinch off their terminal buds?

Match each of the following hormones to its primary role in a plant. a. auxins b. ethylene c. cytokinins d. gibberellins e. abscisic acid 1. at different concentrations, stimulate or inhibit the elongation of shoots and roots 2. produced by roots, promote cell division 3. inhibits seed germination 4. hastens fruit ripening 5. promote fruit development

Match each of the following terms to its meaning. a. gravitropism b. photoperiod c. phototropism d. thigmotropism 1. growth response to light 2. growth response to touch 3. relative lengths of night and day 4. growth response to gravity

In some situations, the amount of nitrogen fertilizer applied to crops has to be increased each year because the fertilizer decreases the rate of nitrogen fixation in the soil. Propose a hypothesis to explain this phenomenon. Describe a test for your hypothesis. What results would you expect from your test?

Interpreting Data A botanist from Harvard University hypothesized that garlic mustard, an invasive plant found in forests of the northeastern United States, suppresses the growth of trees by harming mycorrhizal fungi in nearby soil. To test this hypothesis, soil samples from invaded and uninvaded woodlands were collected, and half the samples were sterilized (to kill any fungi present). Two species of maple tree seedlings were planted, and the growth was calculated (as a percentage increase in the mass of the plant). The graph below presents the data. Do these data support the hypothesis that garlic mustard retards tree growth by harming soil fungi? Sugar maple Red maple Increase in plant biomass (%) 0 300 100 200 Invaded Uninvaded Sterilized invaded Sterilized uninvaded Soil type Seedlings Source K. A. Stinson et al., Invasive plant suppresses the growth of native tree seedlings by disrupting belowground m

Bioremediation is the use of living organisms to detoxify and restore polluted ecosystems. Bioremediation can involve different types of organisms, such as bacteria, protists, and plants. What advantages do you think bioremediation presents over other means of cleaning up polluted sites? If your neighborhood became polluted by a natural disaster, would you prefer bioremediation to more traditional means of cleanup? What if it cost extra or took longer?

Imagine the following scenario: A plant scientist has developed a synthetic chemical that mimics the effects of a plant hormone. The chemical can be sprayed on apples before harvest to prevent flaking of the natural wax that is formed on the skin. This makes the apples shinier and gives them a deeper color. What kinds of questions do you think should be answered before farmers start using this chemical on apples? How might the scientist go about finding answers to these questions?