BIO 110 Tutorials #22-23

Each fall, oak trees drop their acorns.  A lucky acorn will germinate, take root, and grow into a mighty oak tree.  The dry biomass of this mighty oak comes from _____________________. 

• Soil

• Sunlight

• Carbon Dioxide

• Water

• Fertilizers in the soil

A flask of duckweed (an aquatic plant) in water is placed under a bank of lights on a 12-hour light, 12-hour dark cycle, next to a control flask containing only water. Assuming no change in water temperature, which flask will have the lowest dissolved oxygen (DO) concentration, and at what time?

• The flask with duckweed will have the lowest DO at the end of the dark cycle and the highest DO at the end of the light cycle.

•  DO will always be lower in the flask with duckweed compared to the control.

• DO will always be higher in the flask with duckweed compared to the control.

• DO will be the same between the control and the duckweed-containing flask.

In the Calvin cycle, if NADPH begins to run out, what would be the first compound to accumulate?

• 3-phosphoglycerate

• RuBP

• 1,3-bisphosphoglycerate

• glyceraldehyde 3-phosphate

During cellular respiration, ________ serves as an electron acceptor and _______ is produced. During photosynthesis, ______ serves as an electron donor and ______ is produced.

A mutation occurs in the chloroplasts of a lettuce plant, causing its thylakoid membranes to become more permeable to charged ions.

How might this mutation affect the Calvin cycle?

• There would be no change to the Calvin cycle.

• Fewer carbohydrates would be produced by the Calvin cycle.

• More carbohydrates would be produced by the Calvin cycle.

If photosynthesizing green algae are provided with CO₂ containing heavy oxygen (¹⁸O), later analysis will show that all of the following molecules produced by the algae contain ¹⁸O except

•  glyceraldehyde 3-phosphate (G3P).

• glucose

• ribulose bisphosphate (RuBP).

• O₂.

•  3-phosphoglycerate.

In this diagram, Compound X is the CO₂ acceptor. If light is cut off, the first effect would be that

•   Compound X and 3PG will both decrease

• Compound X will increase, 3PG decrease.

• Compound X will decrease, 3PG increase.

• Compound X and 3PG will both increase.

The fixation phase in the Calvin cycle binds one molecule of ___ to one molecule of ____ .

When oxygen is released as a result of photosynthesis, it is a direct by-product of

• the electron transfer system of photosystem I.

• chemiosmosis.

• reducing NADP+.

• splitting water molecules.

During photosynthesis, the energy used to pump protons across the thylakoid membrane comes from _____ , whereas in cellular respiration the energy used to pump protons across the inner mitochondrial membrane comes from _____ and ______ .