Soil Microbial Interactions Quiz

What is the primary role of soil microorganisms?

• Absorbing nutrients directly

• Decomposing organic matter

• Creating soil aggregates

• Increasing soil pH

Which type of symbiotic interaction is primarily responsible for nitrogen fixation in legumes?

• Mycorrhizal association

• Rhizobial symbiosis

• Ectomycorrhizal association

• Endophytic interaction

What is the function of leghemoglobin in nitrogen-fixing nodules?

• Facilitating water uptake

• Storing carbohydrates

• Regulating oxygen levels

• Transporting nitrogen

Which of the following is a characteristic of indeterminate nodules?

• Only found in soybeans

• Develops by cell expansion

• Composed of four distinct zones

• No persistent meristem

What do rhizobia convert from the environment to support plant growth?

• Phosphorus

• Carbon dioxide

• Nitrogen gas

• Oxygen

Which nutrient is primarily scavenged by siderophores secreted by rhizobia?

• Phosphorus

• Sulfur

• Nitrogen

• Iron

What is the primary benefit of arbuscular mycorrhizal fungi (AMF) to plants?

• Enhanced phosphorus acquisition

• Higher water retention

• Increased nitrogen fixation

• Improved photosynthesis

What initiates the signaling pathway for nodule development in legumes?

• Nod factors

• Strigolactones

• Myc factors

• Flavonoids

Which of the following is NOT a zone in indeterminate nodules?

• Fixation zone

• Expansion zone

• Infection zone

• Meristematic zone

What is the role of nitrogenase in nitrogen-fixing bacteria?

• Transporting nitrogen

• Reducing N2 to NH3

• Storing nitrogen

• Regulating oxygen levels