식물영양학 중간고사 2 빈칸 채워넣기

( Mugineic acid ) is an amino acid excreted by some graminaceous (grassy) plants under conditions of iron deficiency as part of a strategy of solubilizing Fe from the root environment for uptake by the plant.

 

Researchers use ( hydroponic ) culture to determine which chemical elements are essential in plants.

 

The most fertile soils are usually loams, made up roughly equal amounts of ( sand ), ( silt ), and ( clay ).

 

( Humus ) is the decomposing organic material formed by the action of bacteria and fungi on dead organisms, feces, fallen leaves, and other organic refuse.

 

Although the atmosphere is nearly 80% nitrogen, plants cannot use it until it is converted to ( NH₄⁺(ammonium) ) or ( NO₃⁻(nitrate) ).

 

( Nitrogenase ) reaction: N2 + 8e- + 8H++16ATP -> 2NH3 +H2 +16ATP +16Pi

 

Members of the legume family have swellings called nodules composed of plant cells that contain nitrogen-fixing bacteria of the genus ( rhizobium ), which will take the form of bacteroids inside the nodules.

 

There are two types of mycorrhizae: ( ectomycorrhizae ) and ( endomycorrhizae ).

 

The ( texture ) and chemical ( composition ) of soil are major factors determining what kinds of plants can grow well in a particular location.

 

Plants contribute (  H⁺ ) by secreting it from root hairs and also by cellular respiration, which releases ( CO₂ ) into the soil solution, where it reacts with H2O to form carbonic acid.

 

Nitrifying bacteria convert ( NH₄⁺ ) to ( NO₃⁻ ).

 

( Cover crop ) is growing a field of plants just to plow them under usually a legume crop, to take care of soil's health, and to put nitrogen back in soil.

 

( Epiphyte ) is an organism that grows upon, or attaches to a living plant.

 

( Glycerid ), more correctly known as acylglycerols,are esters formed from glycerol and fatty acids.

 

( Rubisco ) is an enzyme involved in the first major step of carbon fixation, a process by which atmospheric carbon dioxide is converted by plants to energy-rich molecules such as glucose.

 

Plant roots uptake water, minerals, and ( O₂ ) from soils.

 

Nitrate is reduced to ( nitrite ) by nitrate reductase, then further reduced to ammonia by ( nitrite reductase ) in plants.

 

Sulfate is activated by the formation of adenosine-5'-phosphosulfate and then reduced to ( sulfite ) then to sulfide in plants.

 

If plant cell uptakes water from outside, solute potential (increased or decreased), pressure potential (increased or decreased), and water potential (increased or decreased).

 

In phloem loading, sugar synthesized from mesophyll cell transported to ( bundle sheath ) cell, phloem ( paren chyma ) cell, ( companion ) cell, and ( sieve-tube ) element.

 

In photosynthesis of plants, the light reaction occurs in ( thylakoid membranes ) and dark reaction occurs in ( stroma ) of chloroplast.

 

In photosynthesis of plants, water splitted into ( 1/2 O₂ ), ( 2e⁻ ), and ( 2H⁺ ).

 

In photosynthesis of plants, photophosphorylation is phosphorylation of ( ADP ).

 

In photosynthesis of plants, plants absorb ( red ) light and ( far-red ) light primarily.

 

Which plant hormone is involved in stem elongation and fruit development? ( Gibberellins )

 

Which plant hormone is involved in cell division and seed germination?  ( Cytokinins )

 

Auxin weaken plant cell walls via stimulation of proteins to pump ( H⁺ ) into cell wall and activation of enzymes to break ( H ) bonds between cellulose fibers.

 

'pressure flow hypothesis'

-> Phloem loading induces solute potential (increase or decrease) & water potential (increase or decrease).

-> Accumulation of sucrose in sieve tube promotes water uptake from xylem by ( pressure flow ) mechanism.

-> The mass flow of water from phloem loading to phloem unloading is due to the difference of ( water ) potential.

-> Sugar (actively or passively) transported out of phloem at sink.

 

In plant, sucrose is synthesized in (chloroplast or cytosol).

 

In short distance transport of water, the symplastic pathway involves cytoplasm and ( plasmodesmata ) of plant cells.

 

Stoma opening is stimulated by uptake of ( K⁺ ) ion into guard cells and carbon dioxide induces stoma (opening or closing).

 

Stoma opening and closing are balanced between need to save ( water ) and need to make sugar.

 

( Guttation ): root pressure forces excess water out of leaf.

 

To reduce loss of nitrate via leaching and denitrification, we can use inhibitors of oxidation from ( ammonia ) to nitrite.

(Fe2+ or Fe3+) is uptaked into plant cells through Fe channel.

 

Nutrient gains (  4.  ) and losses (  5.  ) in soils

1. erosion  2. weathering 3. crop removal 4. fertilizer application

5. leaching 6. N-fixation 7. denitrification 8. soil deposits