Plant Physiology Exam quiz and
answers graded A+
What are mineral nutrients? - ANS✅✅chemical elements needed in the diet for normal function,
growth, and maintenance of body tissues, inorganic and essential
What is the experimental evidence that must be provided to establish a mineral nutrient as
essential? What specifically must you demonstrate?
(slide 7, ppt. 1) - ANS✅✅1. Mineral function must be irreplaceable due to the function that it
carries out
2. Nutrient must be required for the completion of a life cycle (of something)
Demonstrate: plant can be grown in hydroponic environment (with the control of the mineral
nutrient availability)
What was the last mineral nutrient discovered? Why did researchers begin
(slide 8 , ppt. 1) - ANS✅✅Nickel
- They began because urease was hypothesized to be an enzyme in plants, and Ni is a component in
urease
What dominates the dry mass of a plant?
- slide 10, ppt. 1 - ANS✅✅Carbon (C) from the atmosphere
How did we discover what the essential nutrients and minerals for plants are?
- slide 10, ppt. 1 - ANS✅✅From experimentation --- and LOTS of it with guessing
,World Growth depends on the availability of what?
- slide 11 , ppt.1 - ANS✅✅the availability of *fertilizer* - without it, we couldn't produce as much
food!
What did the Haber-Bosch process do and how?
- slide 11 , ppt. 1 - ANS✅✅Made fertilization and process of making fertilizers much easier
allowed N to be taken from atmosphere and be converted to ammonium. *We are now free from
the biological reduction of nitrogen to ammonium*.
Why was the Haber-Bosch process important in making fertilization and obtaining N from the
atmosphere easy? What did we do prior to this process in order to obtain
- slide 11, ppt. 1 - ANS✅✅- Prior to this process, N had to be found in terrestrial locations (mainly
islands with lots of birds that defecate)
- feces were used as source of fertilizer because they were rich in nitrogen
When N fertilizer began to be used (after development of Haber-Bosch), what side effect did we
see? why?
- slide 11, ppt. 1 - ANS✅✅a huge spike in burning of fossil fuels
because making N (fertilizer) requires LOTS of energy from the use of fossil fuels!
the cost of N fertilizer directly corresponds with the cost of ___________________?
- explain why
- slide 11, ppt. 1 - ANS✅✅*Energy (and use of oils/gas)*
,- natural gases (N) and the use of fossil fuels and energy is a key component in the production of
fertilizer
Where do we get the nutrients (gasses and minerals) we use in fertilizers? - ANS✅✅- N is obtained
from our atmosphere
- All other nutrients we must mine for
Why do we call the plant nutrients "minerals?" - ANS✅✅- they are inorganic, don't contain C
Nutrient ratios in plants do not match the mineral composition of the soil in which they grow. The
plant is not passively mirroring the soil.
- What does this mean in terms of the plant physiology?
- slide 13, ppt. 1 - ANS✅✅it means that plants have to develop special mechanisms to keep things
IN or to keep other things OUT
- plants have the ability to selectively concentrate (what is going to the inner plant) and exclude
elements present in the soil
When people realized that plants don't mirror the soil, what growing technique was created and
why?
- slide 14, ppt. 1 - ANS✅✅Answer: Hydroponics
- the technique used to selectively control the availability of what mineral nutrients gets
concentrated in plants
List the 4 requirements needed to grow plants using a hydroponic based system.
, - slide 14, ppt. 1 - ANS✅✅1. Without/NO soil
2. Has to be sterile environment
3. Has to be a medium that will not release or absorb ions (CEC)
4. Have to be careful about contamination
Why no soil use in hydroponics? Is there a benefit to this? -
ANS✅✅http://www.bluemittenfarms.com/2017/01/12/5-reasons-why-you-should-use-
hydroponics-instead-of-soil/
1. Saves Water
2. Saves space
3. Forget about Weeding
4. Less Disease and Pests
5. Ultimate Controlled Environment
6. Quick Growth and High Yields
Why is having a sterile environment very important in hydroponics and how does avoiding soil use in
hydroponics help with sterility of the hydroponic environment? - ANS✅✅The soil is a breeding
ground for diseases and pests. When comparing soil vs. hydroponics in the fight of pests and
diseases, hydro takes the trophy. Since you are not using soil, you are assured that no soil-borne
diseases will affect your plants. Soil-borne diseases can cause pain to a farmer and wreck massive
losses. When soil is taken out of the picture, pests that plague traditional gardening are eliminated.
answers graded A+
What are mineral nutrients? - ANS✅✅chemical elements needed in the diet for normal function,
growth, and maintenance of body tissues, inorganic and essential
What is the experimental evidence that must be provided to establish a mineral nutrient as
essential? What specifically must you demonstrate?
(slide 7, ppt. 1) - ANS✅✅1. Mineral function must be irreplaceable due to the function that it
carries out
2. Nutrient must be required for the completion of a life cycle (of something)
Demonstrate: plant can be grown in hydroponic environment (with the control of the mineral
nutrient availability)
What was the last mineral nutrient discovered? Why did researchers begin
(slide 8 , ppt. 1) - ANS✅✅Nickel
- They began because urease was hypothesized to be an enzyme in plants, and Ni is a component in
urease
What dominates the dry mass of a plant?
- slide 10, ppt. 1 - ANS✅✅Carbon (C) from the atmosphere
How did we discover what the essential nutrients and minerals for plants are?
- slide 10, ppt. 1 - ANS✅✅From experimentation --- and LOTS of it with guessing
,World Growth depends on the availability of what?
- slide 11 , ppt.1 - ANS✅✅the availability of *fertilizer* - without it, we couldn't produce as much
food!
What did the Haber-Bosch process do and how?
- slide 11 , ppt. 1 - ANS✅✅Made fertilization and process of making fertilizers much easier
allowed N to be taken from atmosphere and be converted to ammonium. *We are now free from
the biological reduction of nitrogen to ammonium*.
Why was the Haber-Bosch process important in making fertilization and obtaining N from the
atmosphere easy? What did we do prior to this process in order to obtain
- slide 11, ppt. 1 - ANS✅✅- Prior to this process, N had to be found in terrestrial locations (mainly
islands with lots of birds that defecate)
- feces were used as source of fertilizer because they were rich in nitrogen
When N fertilizer began to be used (after development of Haber-Bosch), what side effect did we
see? why?
- slide 11, ppt. 1 - ANS✅✅a huge spike in burning of fossil fuels
because making N (fertilizer) requires LOTS of energy from the use of fossil fuels!
the cost of N fertilizer directly corresponds with the cost of ___________________?
- explain why
- slide 11, ppt. 1 - ANS✅✅*Energy (and use of oils/gas)*
,- natural gases (N) and the use of fossil fuels and energy is a key component in the production of
fertilizer
Where do we get the nutrients (gasses and minerals) we use in fertilizers? - ANS✅✅- N is obtained
from our atmosphere
- All other nutrients we must mine for
Why do we call the plant nutrients "minerals?" - ANS✅✅- they are inorganic, don't contain C
Nutrient ratios in plants do not match the mineral composition of the soil in which they grow. The
plant is not passively mirroring the soil.
- What does this mean in terms of the plant physiology?
- slide 13, ppt. 1 - ANS✅✅it means that plants have to develop special mechanisms to keep things
IN or to keep other things OUT
- plants have the ability to selectively concentrate (what is going to the inner plant) and exclude
elements present in the soil
When people realized that plants don't mirror the soil, what growing technique was created and
why?
- slide 14, ppt. 1 - ANS✅✅Answer: Hydroponics
- the technique used to selectively control the availability of what mineral nutrients gets
concentrated in plants
List the 4 requirements needed to grow plants using a hydroponic based system.
, - slide 14, ppt. 1 - ANS✅✅1. Without/NO soil
2. Has to be sterile environment
3. Has to be a medium that will not release or absorb ions (CEC)
4. Have to be careful about contamination
Why no soil use in hydroponics? Is there a benefit to this? -
ANS✅✅http://www.bluemittenfarms.com/2017/01/12/5-reasons-why-you-should-use-
hydroponics-instead-of-soil/
1. Saves Water
2. Saves space
3. Forget about Weeding
4. Less Disease and Pests
5. Ultimate Controlled Environment
6. Quick Growth and High Yields
Why is having a sterile environment very important in hydroponics and how does avoiding soil use in
hydroponics help with sterility of the hydroponic environment? - ANS✅✅The soil is a breeding
ground for diseases and pests. When comparing soil vs. hydroponics in the fight of pests and
diseases, hydro takes the trophy. Since you are not using soil, you are assured that no soil-borne
diseases will affect your plants. Soil-borne diseases can cause pain to a farmer and wreck massive
losses. When soil is taken out of the picture, pests that plague traditional gardening are eliminated.
