Lecture 23. Thermoregulations and Water Stress in Plants

Question 1

What are the main abiotic factors limiting primary production ?

Answer 1

1. Water

2. Temperature stress

Question 2

What does the inefficiency of photosynthesis result in ?

Answer 2

Under-performance of crop plants

Question 3

What in plants is inextricably linked ?

Answer 3

Temperature and water loss

Question 4

What is a solution to the linkage of temperature and water loss ?

Answer 4

The evolution of different photosynthetic pathways to limit stomatal opening in a day

Question 5

What can plants generate a high amount of ?

Answer 5

Heat

Question 6

What may cause stress to non-native plants ?

Answer 6

Abiotic conditions to which native plants are adapted

Question 7

Where are most agricultural crops cultivated in ?

Answer 7

Regions where they are highly adapted

Question 8

What are the most important abiotic factors that effect plant growth and development ?

Answer 8

1. Water
2. Mineral elements in soil
3. Temperature
4. Light

Question 9

What are the most important abiotic factors in primary production ?

Answer 9

1. Temperature

2. Rainfall

Question 10

Where can terrestrial vascular plants thrive within ?

Answer 10

A wide range of temperature from -5 to 55 degrees celsius

Question 11

Where are terrestrial vascular plants be productive between ?

Answer 11

5 and 40 degrees celsius

Question 12

Where are some species such as aquatic algae be specialised for life ?

Answer 12

Narrow but sometimes extreme temperature ranges

Question 13

Where do ice algae thrive ?

Answer 13

-5 to 5 degrees

Question 14

Where does maize thrive ?

Answer 14

10 to 40 degrees

Question 15

Where does thermophillic algae thrive ?

Answer 15

45 to 50 degrees

Question 16

What is the common pathway that photosynthesis and transpiration share ?

Answer 16

CO2 diffuses in an H2O diffuses out from the leaf via open stomata

Question 17

How is CO2 converted to sugar ?

Answer 17

Uses rubisco

Question 18

Where does the photorespiration pathway occur ?

Answer 18

The chloroplast but also mitochondria and peroxisomes

Question 19

What is a C3 plant ?

Answer 19

The majority of plants - the first carbon compound produced contains three carbon atoms

Question 20

What do the C3 plants do ?

Answer 20

1. Calvin cycle

2. In high temperatures they are at a disadvantage as stomata remain open long and loose water

Question 21

What are C4 plants ?

Answer 21

Found in hot, dry environments and a four carbon compound is produced

Question 22

What do C4 plants do ?

Answer 22

1. Calvin cycle and CO2 pump

2. Reduced stomatal opening in the day, prevents water loss

Question 23

What is the function of pepcarboxylase ?

Answer 23

Produces 4 carbon acids

Question 24

Where are CAM plants found ?

Answer 24

Desert environments

Question 25

What do CAM plants do ?

Answer 25

1. Calvin cycle and CO2 pump

2. Stomata open at night, stores water, highest water use efficiency

Question 26

What does Arum maculatum do ?

Answer 26

Prior to anthesis, plant produces a cone shaped sheath which contains a foul smelling spadix which traps insects for pollination

Question 27

What do the mitochondria of the spadix in the Arum maculatum do ?

Answer 27

Produce heat to vapourise and disperse specific amide and indole chemicals that serve to attract insects

Question 28

What do Symplocarpus foetidus/skunk cabbage do ?

Answer 28

Plants literally melt the snow away from around them by maintaining a temperature of 25 degrees in their immediate vicinity

Question 29

What is thermogenesis related to ?

Answer 29

An increase in the rate of respiration of the spadix

Question 30

How many ATP mols are produced for every glucose ?

Answer 30

28

Question 31

What is the total yield for respiration ?

Answer 31

32 mols of ATP for every glucose equivalent

Question 32

What can cyanide do ?

Answer 32

Knock out cytochromes

Question 33

What can knock out an area of the plant membrane that is resistant to cyanide ?

Answer 33

SHAM