Agronomy Crop Physiology 1

Question 1

What is the primary pigment responsible for capturing light energy during photosynthesis?

Accepted Answer

Chlorophyll a

Answer

Chlorophyll a is the primary photosynthetic pigment that directly participates in the light reactions by absorbing and transferring light energy.

Question 2

Which process describes the loss of water vapor from plant leaves primarily through stomata?

Accepted Answer

Transpiration

Answer

Transpiration is the evaporation of water from plant surfaces through stomata, which creates a water potential gradient that drives water uptake from the soil.

Question 3

What is photorespiration in crop plants?

Accepted Answer

A wasteful process where RuBisCO fixes O2 instead of CO2

Answer

Photorespiration occurs when RuBisCO binds oxygen instead of CO2, releasing previously fixed carbon as CO2 without producing useful sugars, reducing yield.

Question 4

Which photosynthetic pathway do corn (maize) and sugarcane use to efficiently fix carbon in hot climates?

Accepted Answer

C4 pathway

Answer

Corn and sugarcane use the C4 pathway, which spatially concentrates CO2 in bundle sheath cells to minimize photorespiration and improve photosynthetic efficiency.

Question 5

Which plant hormone is the primary driver of fruit ripening and is produced as a gas?

Accepted Answer

Ethylene

Answer

Ethylene is the gaseous plant hormone responsible for accelerating fruit ripening, leaf abscission, and other senescence processes in harvested crops.

Agronomy Practice Test

Agronomy Practice Test

Agronomy Crop Physiology 1