Quiz on Stress Physiology and Temperature Effects on Plants

What is the definition of heat stress in plants?

• Changes from excessively high temperatures

• Responses to nutrient deficiency

• Biochemical changes from excessive water

• Physiological changes due to low temperatures

At what temperature do plants generally start to experience heat stress?

• Above 25°C

• Above 30°C

• Above 50°C

• Above 35–40°C

Which of the following is a response to heat stress in plants?

• Enhanced nutrient uptake

• Increased transpiration

• Closure of stomata

• Decreased leaf temperature

What role do heat shock proteins (HSPs) play during heat stress?

• They increase leaf senescence

• They act as molecular chaperones

• They inhibit protein synthesis

• They promote water loss

Which hormone mediates the expression of heat shock proteins?

• Ethylene

• Auxin

• Abscisic acid (ABA)

• Salicylic acid

What is the effect of elevated temperatures on calcium channels in plants?

• They close to prevent calcium influx

• They reduce calcium levels in the cytosol

• They activate to allow calcium influx

• They have no effect on calcium channels

Which plant adaptation allows for better water access during heat stress?

• Deep and extensive root systems

• Reduced leaf area

• Thick waxy cuticles

• Shallow root systems

What is the primary function of abscisic acid (ABA) in heat stress response?

• Increase nutrient uptake

• Promote cell division

• Regulate stomatal closure

• Enhance photosynthetic activity

Which of the following hormones is involved in defense signaling during heat stress?

• Ethylene

• Cytokinins

• Auxin

• Salicylic acid

What is the effect of heat stress on stomatal behavior?

• Stomata open to increase transpiration

• Stomata increase CO₂ uptake

• Stomata have no response

• Stomata close to reduce water loss