Exam 38: Plant Nutrition and Soils

A plant cell with 64 available ATP molecules could split how many N₂ molecules with the assistance of nitrogenase?

Although symbiotic relationships between nitrogen-fixing bacteria and plants are rare, many plants have symbiotic relationships with

The most important mineral nutrients added to soils in fertilizers are

In lab, you are studying the long term effects of elevated carbon dioxide levels on photosynthesis in C3 and C4 plants.The C3 and C4 plants are growing in separate closed chambers.Both chambers are constantly given elevated but equal amounts of carbon dioixde.Which of the following are likely results of this experiment? Check all that apply._____ There would be a decrease in O₂ levels in both chambers.__X__ There would be an increase in O₂ levels in both containers._____ Both the C3 and the C4 plants would show equal gains in biomass._____ The C4 plants would gain more biomass relative to the C3 plants.__X__ The C3 plants would gain more biomass relative to the C4 plants.

A plant with 80 available ATP could produce 10 molecules of NH₃.

What makes a mineral element essential for plant growth?

A magnesium deficiency would impact the light-independent reactions but not the light-dependent reaction of photosynthesis.

As global temperatures increase, evidence suggests that ribulose 1, 5-biphosphate carboxylase/oxygenase (rubisco) is likely to denature and photosynthesis rates will decrease.

A soil sample with a OH^- concentration of 10^-9 M may also have high levels of aluminum.

Natural communities recycle nutrients, but cultivated communities often require an input of mineral nutrients due to losses through

Why do nitrogen-fixation nodules contain large amounts of leghemoglobin?

Which of the following does not increase the level of nutrients available to crop plants?

Mycorrhizae are especially effective in helping plant roots uptake

When plants are grown in hydroponic culture, their roots are suspended in an aerated solution.Why is the solution aerated? Check all that apply._____ Both the light-dependent and the light-independent reactions of photosynthesis require oxygen.__X__ Oxygen is necessary for the root cells to produce ATP.__X__ Without oxygen, membrane transport in the roots would be impaired._____ A lack of oxygen would cause the water potential within the roots to decrease.__X__ Without oxygen, the xylem would stop flowing.

The Nod factor is an important component of

During the initiation of nitrogen-fixation nodules, how do the Rhizobium bacteria enter into the cortex of the root?

Plants that sequester heavy metals utilize pressure-flow where they move toxins from the source (soil) to a sink (such as the leaves).

A deficiency in a plant micronutrient

A typical root pumps out H⁺ to maintain a strong membrane potential of about

Trichloroethylene (TCE) is toxic to humans because it