Name                                                 .                                                                  2003 02 25

 

Read each question carefully. Answer all questions, as no marks will be deducted for incorrect responses. Value of question appears in parentheses after the question.  Total = 44

 

 

1.         In plants, light-dependent reactions occur in the               of the chloroplast. (1) 

 

A. cytoplasm

B. stroma

C. outer membrane of chloroplast

D. thylakoids of the membrane

 

2.         When reaction centres absorb energy from sunlight,       . (1)

 

A. sugar phosphates are formed

B. RuBP accepts electrons

C. electrons are ejected and transferred to acceptor molecules

D. protons are moved into the thylakoid space

 

3.         The Calvin cycle begins when         . (1)

 

A. light is available

B. light is unavailable

C. carbon dioxide is attached to RuBP

D. rubisco is regenerated

 

 

4.         Match the event with its correct description (5)

 

    C   ATP and NADPH used                A. cyclic photophosphorylation

    E   NADPH formed                          B. non-cyclic photophosphorylation

    B   ATP and NADPH formed            C. Calvin cycle

    A  only ATP formed                         D. splitting of water

   D   Oxygen formed                            E. transfer of electrons to NADP⁺

 

 

5.      Probably the most abundant protein on our planet is      . (1)

 

A. cellulose

B. rubisco

C. RuBP

D. ATP synthase

 

6.      Which sequence correctly portrays the flow of electrons during photosynthesis? (1)

 

A. NADPH  Þ  oxygen  Þ  carbon dioxide

B. water   Þ  NADPH  Þ   Calvin cycle

C. water  Þ  NADH  Þ  ATP

D. water  Þ photosystem I   Þ  photosystem II

 

7.      The stage of photosynthesis that actually forms a molecule of sugar is        . (1)

 

A. photolysis of water

B. light reactions

C. Calvin cycle

D. electron transport system

 

8.      Among the products of carbon fixation, some are used to form sugars, while others are used to                         . (1)

 

A. regenerate rubisco

B. regenerate RuBP

C. replenish the pigments

D. form sugars

 

9.      The oxygen molecules released during the light reaction come from      . (1)

 

A. carbon dioxide

B. water

C. atmospheric oxygen

D. two of the above choices are correct

 

10.  For every molecule of CO₂ fixed by photosynthesis, how many molecules of O₂ are released? (1)

 

A. 1

B. 2

C. 6

D. 12

 

11.     How many molecules of ATP are used to make ONE molecule of G3P (glyceraldehyde 3-phosphate) - a three carbon sugar? (1)

 

A. three

B. six

C. nine

D. eighteen

 

12.     Light-driven electron transport in the chloroplast pumps H⁺ (protons) into the                . (1)

 

A. stroma

B. intermembrane space

C. thylakoid space

D. cytoplasm

 

13.     The oxygen atoms released from the splitting of water are incorporated into     . (1)

 

A. oxygen gas

B. water

C. carbohydrates

D. NADPH

 

14.     Match the following with their correct LOCATION (2)

 

           B   Chlorophyll                                       A.   stroma

           A  Enzymes for carbon fixation               B.   thylakoid membrame

           C  Reservoir of hydrogen ions                 C.  thylakoid space

           B   Photosystems I and II                                  

 

15.     The role of accessory pigments in photosynthesis is to              . (1)

 

A. absorb and pass energy to reaction centre

B. donate electrons to the electron transport chain

C. fix carbon dioxide

D. split water molecules

16. Of the basic processes of photosynthesis (10)

 

            A. cyclic photophosphorylation

            B. non-cyclic photophosphorylation

            C. both light reactions

            D. Calvin cycle

            E. both light reactions and Calvin cycle

 

which process (or combination) involves

 

     D    utilization of CO₂

     E     redox reactions

     C     light energized electrons

      B    production of NADPH

      D   synthesis of G3P

      B    production of O₂

      D   occurrence in the stroma of chloroplast

      B    splitting of water

      C    production of ATP

      A   chlorophyll as initial electron donor and final electron acceptor

      D   the utilization of NADPH

 

 

17. Photorespiration is a problem for plants because                .(1)

 

A. it prevents cellular respiration

B. it stops photons from entering the leaf

C. it takes away half the carbon potential

D. it causes the plant to lose water

 

18. During photosynthesis, an electron transport chain is used to           .(1)

            

A.  transport NADPH from the light-dependent reactions to Calvin cycle

B.   transport electrons from P700 (P/S I) to a primary acceptor

C.   transport electrons from photosystem I to photosystem II

D.  transport electrons from photosystem II to photosystem I

 

 

19. Ribulose is a 5-carbon sugar (monosaccharide) found in plants. Calculate the number of each type of molecule required to synthesize ONE molecule of ribulose OR that are formed as byproducts.  (3.5)

 

Carbon dioxide    5     .

 

ATP    15     . 

 

NADPH    10      .

 

Electrons    20      .

 

Water     10     .

 

Oxygen    5         .

 

Photons    40     .

 

 

20. Give the BALANCED equation for the formation of ribulose.(1.5)

 

5 CO₂ + 10 H₂O ® C₅H₁₀O₅ + 5O₂ + 5 H₂O

 

 

21. What happens during the process called photorespiration?(1)

 

        A. The light-dependent reactions cease to function and photosynthesis stops.

        B. Plants carry on photosynthesis in the dark.

        C. O₂ interferes with the light-independent reactions and slows photosynthesis.

        D. CO₂ inhibits the light-independent reactions of photosynthesis.

 

 

22. The two photosystems of photosynthesis are connected by      . (1)

            

A.  chlorophyll molecules.

B.   an electron transport chain.

C.   NADP molecules.

D.  the stroma.

 

23. Rubisco is   . (1)

            

A. the enzyme that first captures CO₂ to begin the Calvin cycle.

B. the enzyme responsible for splitting H₂O to produce O₂ in photosynthesis.

C. the  end product of the photochemical reactions

D. the 5-carbon sugar molecule that reacts with CO₂ to begin the Calvin cycle

 

24. When green light strikes a chloroplast,          . (1)

 

A.  it excites the electrons of chlorophyll.

B.   it is converted to chemical energy.

C.   it is absorbed by chlorophyll.

D.  it is transmitted or reflected.

 

25. The CO₂ reduction pathway that separates carbon fixation from the Calvin cycle temporally    (in time) is                     . (1)

 

A. the Calvin cycle

B. CAM pathway

C. C4 pathway

D. PSII

26. The flow of                   through channel proteins drives the formation of ATP. (1)

 

A. hydrogen ions

B. electrons

C. water

D. NADPH

27.  Carbon dioxide is produced during               . (1)

 

A.  the light-dependent reactions.

B. the Calvin cycle.

C. photorespiration.

D. none of the above

 

BONUS:

1. How many G3P molecules can be made in a C4 plant from 48 photons? (1)  two

48photons  /8 photons per carbon  = 6 carbons which can form two molecules of G3P

2. How many G3P molecules can be made in a CAM plant from 48 ATP? (1)  four

48 ATP / 4ATP per carbon = 12 carbons which can form four molecules of G3P

 

3. Who stated that light travels in packets of energy called photons? (1) Albert Einstein

 

4. What part of the leaf controls the opening and closing of stomata? (1) guard cells