Plant Responses To The Environment

Question 1

Chilling occurs when

Answer 1

This occurs at temperatures between 1 to 5°C for 24 hours or more.

Question 2

the main damage caused by chilling is to the

Answer 2

damage of membranes

Question 3

What happens during chilling

Answer 3

leakage of ions out of the cell
inefficient functioning of photosynthetic or respiratory ATP synthesis
evidence include leaf lesions (necrotic spots on the leaves) and wilting

Question 4

chill-sensitive plants (not adapted nor acclimated) have a _____ proportion of saturated fatty acids (i.e. stearic acid) particularly as part of membrane phospholipids. Why is this important

Answer 4

Higher, all have single bonds, saturated with hydrogen, fat freezes easier in even higher temperature, membranes change from fluid to gel as temps drop, lose function

Question 5

Linoleic acid

Answer 5

increase the proportion of unsaturated fats in the membranes

Question 6

Jasmonic acid

Answer 6

Enzyme that is responsible for transcription and translation of desaturases (enzymes that desaturate the fatty acids) when exposed to chilling temperatures