Plant Physiology and Photosynthesis Unit Test

Plant Physiology and Photosynthesis

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1. In vascular plants, transport of sugar solutions is through tubes constructed of cells called:

a. Vessel elements

b. Companion cells

c. Tracheids

d. Sieve-tube elements

2. All the following are true of companion cells except:

a. Companion cells fuse together to form the sieve plates of sieve-tube elements.

b. Companion cells provide direct nourishment for sieve-tube elements.

c. Companion cells regulate the movement of sugar into and out of sieve-tubes.

d. Sieve-tube plasma membrane may be repaired by companion cells.

3. What type of tissue transports the products of photosynthesis to cells that are metabolically active?

a. Xylem

b. Mesophyll

c. Phloem

d. Parenchyma

4. All the following are true of xylem except:

a. Tracheids and vessel elements are the two types of cells that form xylem.

b. Water and minerals are transported through xylem.

c. Companion cells provide nutrition for tracheids.

d. Tracheids are characterized by pits.

5. In general, which of the following accounts for the movement of most minerals from soil into root hairs?

a. Diffusion

b. Osmosis

c. Active transport

d. Hypotonicity

6. Generally, what do plants require to meet the demands of their metabolic activities?

a. Carbohydrates, light, water and nitrogen

b. Light, oxygen, carbon dioxide, water, and minerals

c. Carbon dioxide, oxygen, proteins and minerals

d. Water, carbohydrates, proteins, and minerals

7. Which of the following elements is essential for the synthesis of chlorophyll?

a. Calcium

b. Magnesium

c. Potassium

d. Manganese

8. The movement of water and minerals through xylem is explained by the:

a. Pressure-flow theory

b. Translocation theory

c. Bulk-flow theory

d. Cohesion-tension theory

9. Water loss through the stomata of leaves is termed:

a. Transpiration

b. Translocation

c. Evaporation

d. Osmosis

10. A plant, by opening and closing its stomata, must achieve a balance between:

a. Oxygen loss and water uptake

b. Carbon dioxide loss and sugar uptake

c. Water loss and carbon dioxide uptake

d. Sugar loss and oxygen uptake

11. An essential plant nutrient required for the regulation of stomatal opening and closing is:

a. Phosphate

b. Calcium

c. Magnesium

d. Potassium

12. Where do the light independent reactions of photosynthesis occur?

a. Thylakoids

b. Cytoplasm

c. Stroma

d. Matrix

13. During the process of photosynthesis, light energy is captured
directly by:

a. Protons from NADPH

b. Electrons from chlorophyll

c. Phosphate from ATP

d. Carbons from carbon dioxide molecules

14. The vast majority of chloroplasts found in a leaf are located where?

a. Spongy Mesophyll

b. Palisade Mesophyll

c. Epidermis

d. Guard Cells

15. A leaf appears red in the autumn because:

a. Absorbs green light

b. Reflects or transmits green light

c. Absorbs blue and yellow light

d. Reflects or transmits red light

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Part B: Short Answer

1. The following is an absorption spectrum for a photosynthetic pigment in green plants:

Hint: Red light has the longest wavelength

a. Describe the results at points 425 nm and 650 nm in terms of the amount and colour of light absorbed (or not).

b. Name this pigment.

c. Where is this pigment located in the plant cell?

d. What immediately happens to the energy absorbed by this pigment?

2. The overall equation for photosynthesis is:

6 CO₂ + 12 H₂O -----> C₆H₁₂O₆ + 6 O₂ + 6 H₂O

If either of the reactants is limiting, photosynthesis grinds to a stop.

a. Explain how CO2 is transported from the atmosphere to the site of photosynthesis, including how this transport is regulated.

b. What is the first thing that happens to CO2 when it reaches the site of photosynthesis?

c. Explain how H2O is transported from the soil to the site of photosynthesis.

d. Which mechanism is responsible for the majority of water transport?

e. What is the purpose of the water in photosynthesis?

3. The graph below shows the sugar relationships of a plant under full sunlight. Use the information shown in this graph to answer the questions below.

a. If a plant was placed in full sunlight at 25^oC for 48 hours, what would be the net effect on the sugar content of the plant? Explain your answer.

b. Explain what is happening to the plant above 40^oC.

4. What advantage do dry climate plants(C4 plants) have over C3 plants?

5. In photosynthesis, specific steps in the energy-trapping and carbon-fixing processes are associated with specific compounds. Select the BEST letter from the column on the right and place it in the blank next to each correct substance in the column on the left. (Letters can be used more than once)

_____ 1. Carbon Dioxide A. product of chemiosmotic phosphorylation

_____ 2. NADPH B. end product of electron transport reactions

_____ 3. oxygen C. product of photolysis

_____ 4. ATP D. product of carbon fixation cycle

_____ 5. Phosphoglyceraldehyde E. raw material for carbon fixation cycle

6 a. Draw and label the internal structure of the chloroplast.

b. From your diagram in part a describe the location of the following:

i) phycocyanin _______________________

ii) ribulose phosphate ____________________

iii) ATPase ____________________________

iv) high[H⁺] for ATP synthesis __________________________

7. With the aid of diagrams, explain how the energy in sunlight is transferred to NADPH and ATP in the chloroplasts and of green plants. Then show how this energy is used in the light-independent reactions (Answer on the back of the page).

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