The photosynthetic event known as the Calvin cycle occurs in the

     How does carbon dioxide enter the leaf?
 
   A.    through the mesophyll
   B.    through the stomata
   C.    through the stem
   D.    through the chloroplasts
   E.    through the roots

Question 2   
     The photosynthetic event known as the Calvin cycle occurs in the __________.
 
   A.    thylakoid membrane
   B.    stroma
   C.    (inner) thylakoid space
   D.    stomata
   E.    matrix

Question 3   
     In photosynthesis, plants use carbon from ________ to make sugar and organic molecules.
 
   A.    carbon dioxide
   B.    soil
   C.    chlorophyll
   D.    water
   E.    the sun

Question 4   
     The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from _____.
 
   A.    light
   B.    carbon dioxide
   C.    radioisotopes
   D.    water
   E.    glucose

Question 5
     Light reactions do all of the following EXCEPT:
 
   A.    absorb photons
   B.    convert sunlight to chemical energy
   C.    synthesize ATP and NADPH
   D.    convey excited electrons from chlorophyll to an electron acceptor
   E.    reduce carbon dioxide

Question 6 
     Both mitochondria and chloroplasts _______________.
 
   A.    release oxygen as a by-product
   B.    use a hydrogen ion (proton) gradient to produce ATP
   C.    are surrounded by a single membrane
   D.    obtain electrons from water
   E.    reduce NAD+, forming NADP

Question 7   
     Why are C4 plants more suited to hot climates than C3 plants?
 
   A.    They do not close their stomata in hot, dry weather.
   B.    They evolved in cold weather but migrated to the tropics where they were more suitable.
   C.    Unlike C3 plants, they keep fixing carbon dioxide even when the concentration of carbon dioxide in the leaf is low.
   D.    The same cells that bind carbon dioxide perform the Calvin cycle.
   E.    They suspend photosynthesis in the heat.

Question 8   
     Chlorophyll molecules are in which part of the chloroplast?
 
   A.    stroma
   B.    plasma membrane
   C.    Golgi apparatus
   D.    stomata
   E.    grana stacks

Question 9   
     The most important role of pigments in photosynthesis is to ____________.
 
   A.    store energy in glucose molecules
   B.    store energy in ATP
   C.    capture light energy
   D.    screen out harmful ultraviolet rays
   E.    release energy from glucose molecules

Question 10   
     You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark?
 
   A.    While it did have access to light, the plant stored energy in the form of sugars or starch, and it was able to derive energy from the stored molecules during your vacation.
   B.    When light energy is not available, plants can derive energy from inorganic molecules.
   C.    Even though it can't carry out the light reactions, the plant can still produce sugars because the Calvin cycle doesn't require light.
   D.    Even though the plant received no visible light, it was able to use the short-wave part of the electromagnetic spectrum (gamma rays and X-rays) to carry out photosynthesis.
   E.    none of the above