Erin hypothesizes that a certain fertilizer will cause her sunflowers to grow better. She plants 12 plants chooses the first 6 that sprout to treat with the fertilizer. She measures all the plants daily, and notices that the treated plants were an average of 2 cm taller at 6 weeks. She concludes that the fertilizer causes the plants to grow faster. Which fact would lead you to question Erin’s conclusion?     The first plant to sprout was treated with the fertilizer.     Erin treated the first 6 plants that sprouted.     The treated plants were an average of 2 cm taller at 6 weeks.     Erin’s friends also conducted the same experiment.

Figure 31.10 Farmers often rotate corn (a cereal crop) and soy beans (a legume) planting a field with each crop in alternate seasons. What advantage might this crop rotation confer?

Name four major ways human societies rely on seed plants.

Owners and managers of plant nurseries have to plan lighting schedules lor a long-day plant that will flower in February. What lighting periods will be most effective? What color of light should be chosen?

In flowers, the structures that produce male gametophytes are called _______ ;the strcutures that produce female gametophytes are called _______ . a. pollen grains; flowers c. anthers; stigma b. stamen; carpels d. megaspores; microspores

TCE Uptake by Transgenic Plants Plants used for phytoremediation take up organic pollutants, then transport the chemicals to plant tissues, where they are stored or broken down. Researchers are now designing transgenic plants with enhanced ability to take up or break down toxins. In 2007, Sharon Doty and her colleagues published the results of their efforts to design plants for phytoremediation of soil and air containing organic solvents. The researchers used Agrobacterium tumefaciens (Section 15.7) to deliver a mammalian gene into poplar plants. The gene encodes cytochrome P450, an enzyme involved in the breakdown of a range of organic molecules, including solvents such as TCE. FIGURE 28.16 shows data from one test on the resulting transgenic plants. FIGURE 28.16 TCE uptake from air by transgenic poplar plants. Indvioual potted plants were kept in separate seated containers with an initial level of TCE (trichloroethytene) around 15.0C0 micrograms per cubic meter of air. Samples of the air m the containers were taken daily and measured for TCE content. Controls included a tree transgenic for a Ti plasmid with no cytochrome P450 in it (vector control), and a bare-root transgenic tree (one that was not planted in soil. 1. How many transgenic plants did the researchers test?

TCE Uptake by Transgenic Plants Plants used for phytoremediation take up organic pollutants, then transport the chemicals to plant tissues, where they are stored or broken down. Researchers are now designing transgenic plants with enhanced ability to take up or break down toxins. In 2007, Sharon Doty and her colleagues published the results of their efforts to design plants for phytoremediation of soil and air containing organic solvents. The researchers used Agrobacterium tumefaciens (Section 15.7) to deliver a mammalian gene into poplar plants. The gene encodes cytochrome P450, an enzyme involved in the breakdown of a range of organic molecules, including solvents such as TCE. FIGURE 28.16 shows data from one test on the resulting transgenic plants. FIGURE 28.16 TCE uptake from air by transgenic poplar plants. Indvioual potted plants were kept in separate seated containers with an initial level of TCE (trichloroethytene) around 15.0C0 micrograms per cubic meter of air. Samples of the air m the containers were taken daily and measured for TCE content. Controls included a tree transgenic for a Ti plasmid with no cytochrome P450 in it (vector control), and a bare-root transgenic tree (one that was not planted in soil. 2. In which group did the researchers see the slowest rate of TCE uptake? The fastest?

TCE Uptake by Transgenic Plants Plants used for phytoremediation take up organic pollutants, then transport the chemicals to plant tissues, where they are stored or broken down. Researchers are now designing transgenic plants with enhanced ability to take up or break down toxins. In 2007, Sharon Doty and her colleagues published the results of their efforts to design plants for phytoremediation of soil and air containing organic solvents. The researchers used Agrobacterium tumefaciens (Section 15.7) to deliver a mammalian gene into poplar plants. The gene encodes cytochrome P450, an enzyme involved in the breakdown of a range of organic molecules, including solvents such as TCE. FIGURE 28.16 shows data from one test on the resulting transgenic plants. FIGURE 28.16 TCE uptake from air by transgenic poplar plants. Indvioual potted plants were kept in separate seated containers with an initial level of TCE (trichloroethytene) around 15.0C0 micrograms per cubic meter of air. Samples of the air m the containers were taken daily and measured for TCE content. Controls included a tree transgenic for a Ti plasmid with no cytochrome P450 in it (vector control), and a bare-root transgenic tree (one that was not planted in soil. 3. On day 6, what was the difference between the TCE content of air around planted transgenic plants and that around vector control plants?

TCE Uptake by Transgenic Plants Plants used for phytoremediation take up organic pollutants, then transport the chemicals to plant tissues, where they are stored or broken down. Researchers are now designing transgenic plants with enhanced ability to take up or break down toxins. In 2007, Sharon Doty and her colleagues published the results of their efforts to design plants for phytoremediation of soil and air containing organic solvents. The researchers used Agrobacterium tumefaciens (Section 15.7) to deliver a mammalian gene into poplar plants. The gene encodes cytochrome P450, an enzyme involved in the breakdown of a range of organic molecules, including solvents such as TCE. FIGURE 28.16 shows data from one test on the resulting transgenic plants. FIGURE 28.16 TCE uptake from air by transgenic poplar plants. Individual potted plants were kept in separate seated containers with an initial level of TCE (trichloroethylene) around 15,000 micrograms per cubic meter of air. Samples of the air in the containers were taken daily and measured for TCE content. Controls included a tree transgenic for a Ti plasmid with no cytochrome P450 in it (vector control), and a bare-root transgenic tree (one that was not planted in soil. 4. Assuming no other experiments were done, what two explanations are there for the results of this experiment? What other control might the researchers have used?

Roots that enable a plant to grow on another plant are called.______ epiphytic roots prop roots adventitious roots aerial roots