Exam 36: Plant Nutrition

The micronutrient iron is abundant in soil but often unavailable to plants due to insolubility. Knowing that the reaction Fe(OH)3 + 3 H+ ↔ Fe3+ + 3 H2O occurs, and assuming all soil samples have the same total amount of iron, which type of soil would you predict to have the highest amount of soluble iron?

A mineral deficiency is likely to affect older leaves more than younger leaves if the ________.

Which of the following would be the most effective strategy to remove toxic heavy metals from a soil?

Agricultural lands frequently require nutrient augmentation because ________.

Which of the following plant structures shares the most common features and functions with a fungal hyphae?

If you wanted to increase the cation exchange and water retention capacity of loamy soil, you should ________.

After mutagenesis, the nitrogen-fixing bacterium Sinorhizobium meliloti could no longer colonize Medicago truncatula plants. This inability to colonize was due to the absence of recognition by the host plant. Which of the following genes is most likely the site of the mutation in these bacteria?

After mutagenesis and screening, you have found a mutant that is able to grow in soil with high salt content. Chemical analysis showed that this plant has a decreased amount of Na+ throughout the entire plant relative to normal plants. What kind of mutation do you predict this plant contains?

Which of the following contributed to the dust bowl in the American southwest during the 1930s? I. overgrazing by cattle II. clear-cutting of forest trees III. plowing of native grasses IV. lack of soil moisture

Which elements are most often the limiting nutrients for plant growth?

A rootless, green plant is found growing on the branches and trunks of rain forest trees but lacks any apparent adaptation for collecting rainwater. This plant is most likely ________.

A major function of magnesium in plants is to ________.

Which of the following soil minerals is most likely leached away during a hard rain in high clay soil?

What soil composition would be best for availability of nutrients, water, and root development?

Which of the following statements about nitrogen fixation in root nodules is correct?

While hiking in a forest, you notice an unusual plant growing on the branches of a tree. What will help you to determine if this plant is epiphytic or parasitic?

In a root nodule, the gene coding for nitrogenase ________.

Why do plants use cotransporters instead of ion channels to transfer anions into cells?

What is the correct sequence of steps during infection of plants by nitrogen-fixing bacteria?

Which of the following elements is required for the stability of cell walls?