Crop Physiology

Question 1

metabolic energy transformations

Answer 1

critical for plants’ survival

Question 2

photosynthesis

Answer 2

plants convert sunlight energy to chemical energy

Question 3

respiration

Answer 3

plants convert sugars and starches to energy for metabolism of cells

Question 4

transpiration

Answer 4

loss of water from the stomata of plants

Question 5

symbiotic nitrogen fixation

Answer 5

process that makes atmospheric nitrogen available to legumes

Question 6

photoperiodism

Answer 6

the reaction of plants to changing lengths of darkness

Question 7

vernalization

Answer 7

photoperiod response during the winter that is important for triggering flowering in the spring

Question 8

plants are categorized as what based on their life cycle

Answer 8

annual, biennial, or perennial

Question 9

metabolism

Answer 9

the group of vital biochemical reactions that occurs in the cells of living organisms

Question 10

mesophyll cells have ____________ that include green ____________

Answer 10

chloroplasts; chlorphylls

Question 11

light reactions

Answer 11

harvest sunlight for energy

Question 12

two main energy compounds

Answer 12

ATP and NADPH

Question 13

carbon-fixation reactions

Answer 13

Calvin cycle = C3 cycle

Question 14

C3 plants (temperate regions)

Answer 14

alfalfa, wheat, soybeans, cotton, tobacco, peanuts

Question 15

C4 plants (tropical enevironments)

Answer 15

corn, sorghum, millet, big bluestem, Indiangrass, switchgrass

Question 16

CAM plants (stomata only open at night; more drought tolerant)

Answer 16

cacti and pineapple

Question 17

photorespiration

Answer 17

reverse photosynthesis; occurs during a drought and uses more carbon energy

Question 18

sugars from photosynthesis

Answer 18

ATP energy

Question 19

glucose + oxygen ->

Answer 19

carbon dioxide + water + energy

Question 20

four primary processes of respiration

Answer 20

1. glycolysis (produces energy)
2. pyruvate enters the mitochondria and is split into CO2 and acetyl CoA
3. Krebs cycle uses acetyl CoA to produce ATP and NADH
4. oxidative phosphorylation occurs within the mitochondria

Question 21

photosynthesis characteristics

Answer 21

• occurs in light
• produces sugars
• stores energy
• uses H2O
• uses CO2
• releases O2

Question 22

respiration characteristics

Answer 22

• occurs in dark and light
• uses sugars
• releases energy
• produces H2O
• produces CO2
• uses O2

Question 23

higher temp =

Answer 23

greater respiration

Question 24

transpiration is important for:

Answer 24

• cooling the plant
• movement of nutrients within the plant
• uptake of mineral nutrients

Question 25

five factors that affect transpiration

Answer 25

1. # and size of stomata 2. presence of soil moisture 3. air temperature 4. air moisture content (humidity) 5. wind or air movement increases the transpiration pull

Question 26

evapotranspiration

Answer 26

the plant's total water use

Question 27

ET ratio

Answer 27

weight of water required to produce the weight of the crop's dry matter

Question 28

pubescence

Answer 28

short hairs that cover leaf surfaces

Question 29

cuticle

Answer 29

thick, waxy coating on leaves

Question 30

symbiotic nitrogen fixation

Answer 30

a process that makes atmospheric nitrogen available to some plants

Question 31

nitrogen fixed per year (lbs/ac) of alfalfa, red clover, and soybeans

Answer 31

alfalfa: 70-200 red clover: 60-200 soybeans: 20-200

Question 32

nodule formation

Answer 32

1. root hairs grow and release root exudates 2. rhizobia attatch to the root hair surface 3. root hairs curl and trap rhizobia 4. rhizobia digest the cell wall 5. rhizobia induce division of the root cells 6. nodule is formed from the protrusion of the root cells to the root surface 7. bacteria of the individual root cells develop the nitrogenase enzyme and fix atmospheric nitrogen

Question 33

phytochrome

Answer 33

pigment that senses changes in amounts of red and far-red light

Question 34

short-day flowering response

Answer 34

late summer of fall-flowering plants do not flower in the longest days of the summer ex. corn, soybeans, cotton, and rice

Question 35

long-day flowering response

Answer 35

flower when the photoperiod is longer than a certain period spring or early summer flowering plants ex. smooth bromegrass and wheat

Question 36

day neutral flowering response

Answer 36

flower after a certain age or when a certain level of growth has been achieved ex. ever-bearing strawberries, cucumber, and tomatoes

Question 37

dormancy response

Answer 37

perennial plants have a dormancy period

Question 38

seed germination response

Answer 38

light activates vegetative growth of the epicotyl

Question 39

wheat requires ____ photoperiods and ___ temperatures

Answer 39

short; low

Question 40

dry matter

Answer 40

the weight of all the components of a plant minus the water

Question 41

general development stages

Answer 41

1. seed 2. seedling 3. vegetative 4. flowering 5. fruit 6. seed 7. senescence

Question 42

growing degree days

Answer 42

an index of heat accumulation (or heat units over time)

Question 43

what temperature range is beneficial to crops

Answer 43

50 - 86 degrees F