STEP GRADE 9

Name: ____________________________________ Date: ___________________

For questions 1 – 9 circle the correct answers.

1. One bean plant is illuminated with green light and another bean plant of similar size and leaf area is illuminated with blue light. If all other conditions are identical, how will the photosynthetic rates of the plants most probably compare?

a) Neither plant will carry on photosynthesis

b) The plant under the blue light will carry on photosynthesis at a greater rate than the one under the green light.

c) Photosynthesis will occur at the same rate in both plants.

d) The plant under the green light will carry on photosynthesis at a greater rate than the one under the blue light.

2. An organic compound formed is the dark reactions of photosynthesis is

a) glucose

b) Chlorophyll

c) Oxygen

d) Water

3. The rate of photosynthesis carried on by plants living in a body of water depends chiefly upon the

a) number of decomposers in the water

b) amount of molecular oxygen in the water

c) amount of light that penetrates the water

d) number of saprophytes in the water

4. Which word equation best represents the process of photosynthesis

a) glucose --> alcohol + carbon dioxide

b) carbon dioxide + water --> glucose + oxygen

c) maltose + water --> glucose + glucose

d) glucose + oxygen --> carbon dioxide + water

5. At optimum light intensity, which atmospheric gas most directly influences the rate of photosynthesis

a) carbon dioxide

b) nitrogen

c) oxygen

d) hydrogen

6. For the given statement, choose the process that is best described by the statement:

Light energy is absorbed by pigment molecules

a) aerobic respiration

b) anaerobic respiration

c) light reactions of photosynthesis

d) dark reactions of photosynthesis

7. The light reactions of photosynthesis occur in the __________,
and the dark reactions occur in the __________ of the chloroplast.

a) Stroma, grana

b) thylakoid membranes, stroma

c) thylakoid membranes, chlorophyll

d) stroma, thylakoids

8. The overall source of energy for photosynthesis is:

a) energy of electron transport in the thylakoid membrane

b) energy released when water is oxidized and oxygen is produced

c) energy from the hydrolysis of ATP

d) light energy from the sun

9. Answer true or false.

Chlorophyll absorbs red and green light and reflects blue.

a) True

b) False

10. The internal and external structure of leaves make them very well adapted for photosynthesis. Choose four (4) features of leaves and describe how these features efficient organs for photosynthesis. (8)

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11. Label the following diagram. (3)

Total 20 points