Exam 37: Soil and Plant Nutrition

You are conducting an experiment on plant growth. You take a plant fresh from the soil that weighs 5 kg. Then you dry the plant overnight and determine the dry weight to be 1 kg. Of this dry weight, how much would you expect to be made up of organic molecules?

Which of the following is not True of micronutrients in plants?

The enzyme complex nitrogenase catalyzes the reaction that reduces atmospheric nitrogen to

When performing a mineral nutrition experiment, researchers use water from a glass still. Why is it not a good idea to use regular distilled water from a stainless steel still?

What is the function of a root nodule's leghemoglobin?

Two groups of tomatoes were grown under laboratory conditions, one with humus added to the soil and one a control without the humus. The leaves of the plants grown without humus were yellowish (less green)compared with those of the plants grown in humus-enriched soil. The best explanation for this difference is that

The rhizosphere would best be described as

What are the three main elements on which plant growth and development depend?

You are weeding your garden when you accidentally expose some roots. You notice swellings (root nodules)on the roots. Most likely your plant

In the 1640s Jan Baptista van Helmont planted a small willow in a pot that contained 90.9 kg of soil. After five years, the plant weighed 76.8 kg, but only 0.06 kg of soil had disappeared from the pot. What did van Helmont conclude from this experiment?

In west Texas, cotton has become an important crop in the last several decades. However, in this hot, dry part of the country there is little rainfall, so farmers irrigate their cotton fields. They must also regularly fertilize the cotton fields because the soil is very sandy. Figure 37.2 shows the record of annual productivity (measured in kilograms of cotton per hectare of land) since 1960 in a west Texas cotton field. Use these data to answer the following questions. Figure 37.2 -If you were the county agriculture agent, what would be the best advice you could give the farmer who owns the field under study in Figure 37.2?

Most of the mass of organic material of a plant comes from

Iron deficiency is often indicated by yellowing in newly formed leaves. This suggests that iron

Some plants extract and concentrate heavy metals from the soil. A current use for such plants is

There are several properties of a soil in which typical plants would grow well. Of the following, which would be the least conducive to plant growth?

Carnivorous adaptations of plants mainly compensate for soil that has a relatively low content of

If a plant is infected with Rhizobium, what is the probable effect on the plant?

In a root nodule, the gene coding for nitrogenase

Dwarf mistletoe grows on many pine trees in the Rockies. Although the mistletoe is green, it is probably not sufficiently active in photosynthesis to produce all the sugar it needs. The mistletoe also produces haustoria. Thus, dwarf mistletoe growing on pine trees is best classified as

In west Texas, cotton has become an important crop in the last several decades. However, in this hot, dry part of the country there is little rainfall, so farmers irrigate their cotton fields. They must also regularly fertilize the cotton fields because the soil is very sandy. Figure 37.2 shows the record of annual productivity (measured in kilograms of cotton per hectare of land) since 1960 in a west Texas cotton field. Use these data to answer the following questions. Figure 37.2 -Based on the information provided above, what is the most likely cause of the decline in productivity?