Mastering Bio Ch. 10 – Flashcards

Plants are photoautotrophs. What does this mean? a. They generate oxygen. b. They synthesize their own food from inorganic materials. c. They are attracted to light. d. They use light energy to drive the synthesis of organic molecules from inorganic materials. e. They are the primary consumers of the biosphere.

The ultimate source of energy to support most life on Earth is _____. a. chemosynthetic microbes b. photosynthetic plants c. sunlight d. the carbon cycle e. geothermal heat

The photosynthetic membranes are found in the _____ in plant cells. a. mitochondria b. Golgi apparatus c. chloroplasts d. nucleus e. endoplasmic reticulum

Every ecosystem must have _____. a. autotrophs and heterotrophs b. producers and primary consumers c. autotrophs d. photosynthesizers

*experiment* Trial Grams of baking soda (CO22 source) Wattage of light bulb Disks floating at 10 minutes 1 0.5 25 3 2 0.5 50 5 3 0.5 75 9 4 0 75 0 Use your knowledge of the mechanism of photosynthesis and the data presented in the chart to determine which of the statements below is a correct explanation for the student's data. a. Cup 4 had the slowest rate of photosynthesis because it had the least baking soda. b. Cup 2 had the highest rate of photosynthesis because 5 disks were floating at the end of 10 minutes using a 50 watt light bulb. c. Cup 3 had the same rate of photosynthesis as Cup 1 because they had the same ratio of disks floating to wattage of light. d. Cup 1 had a low rate of photosynthesis because 0.5 grams of baking soda did not provide a sufficient amount of CO2.

In the electromagnetic spectrum, the type of radiation that we call visible light occurs between _____. a. X-rays and ultraviolet radiation b. radio waves and microwaves c. infrared radiation and microwaves d. infrared radiation and radio waves e. ultraviolet radiation and infrared radiation

Which of the following is a product of the light reactions of photosynthesis? a. NADP+ and RuBP b. glyceraldehyde-3-phosphate c. oxygen, ATP, and NADPH d. water and CO2 e. high-energy photons

When light strikes chlorophyll molecules, they lose electrons, which are ultimately replaced by _____. a. splitting water b. fixing carbon c. removing them from NADPH d. breaking down ATP e. oxidizing glucose

Photosynthesis is a redox reaction. This means that H2O is _____ during the light reactions and CO2 is _____ during the Calvin cycle. a. reduced...reduced b. consumed...reduced c. oxidized...reduced d. reduced...oxidized e. consumed...consumed

*What did Engelmann conclude about the congregation of bacteria in the red and blue areas? a. Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis. b. Bacteria congregated in these areas due to an increase in the temperature of the red and blue light. c. Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths. d. Bacteria congregated in these areas because these areas had the most oxygen being released.

Why are there several structurally different pigments in the reaction centers of photosystems? a. They enable the reaction center to excite electrons to a higher energy level. b. This arrangement enables the plant to absorb light energy of a variety of wavelengths. c. They enable the plant to absorb more photons from light energy, all of which are at the same wavelength. d. Excited electrons must pass through several pigments before they can be transferred to electron acceptors of the electron transport chain.

As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy? a. It is lost as heat. b. It is used to phosphorylate NAD+ to NADPH, the molecule that accepts electrons from photosystem I. c. It is used to establish and maintain a proton gradient. d. It excites electrons of the reaction center of photosystem I.

The final electron acceptor associated with photosystem I is _____. a. NADPH b. oxygen c. NADP d. water

*Which wavelengths of light drive the highest rates of photosynthesis? Select the two best answers. a. 400-450 nm b. 500-600 nm c. 550-700 nm d. 670-680 nm

Which of the following products of the light reactions of photosynthesis is consumed during the Calvin cycle? a. water b. NADPH c. oxygen d. ADP + Pi e. sugar

The overall function of the Calvin cycle is _____. a. producing carbon dioxide b. oxidizing glucose c. capturing sunlight d. splitting water e. making sugar

**Refer to the figure. If the carbon atom of each of the incoming CO2 molecules is labeled with a radioactive isotope of carbon, which organic molecules will be radioactively labeled after one cycle? a. B, C, D, and E b. C only c. B and C only d. C, D, and E only

Refer to the figure. To identify the molecule that accepts CO2, Calvin and Benson manipulated the carbon-fixation cycle by either cutting off CO2 or cutting off light from cultures of photosynthetic algae. They then measured the concentrations of various metabolites immediately following the manipulation. How would these experiments help identify the CO2 acceptor? a. The CO2 acceptor concentration would decrease when either the CO2 or light are cut off. b. The CO2 acceptor concentration would decrease when the CO2 is cut off, but increase when the light is cut off. c. The CO2 acceptor concentration would increase when the CO2 is cut off, but decrease when the light is cut off. d. The CO2 acceptor concentration would increase when either the CO2 or light are cut off.

C4 plants occur more commonly in desert conditions because _____. a. they produce water as a product of their photosynthetic pathways b. they can fix carbon at the lower CO2 concentrations that develop when the stomata are closed c. they produce carbon dioxide internally via photorespiration d. the stomata open at night and close in the day e. they store carbon by incorporating CO2 into organic acids that are later catabolized

**Use your knowledge of the mechanism of photosynthesis and the data presented in the chart to determine which of the statements below is a correct explanation for the student's data. a. Cup 1 had a low rate of photosynthesis because 0.5 grams of baking soda did not provide a sufficient amount of CO2. b. Cup 3 had the same rate of photosynthesis as Cup 1 because they had the same ratio of disks floating to wattage of light. c. Cup 4 had the slowest rate of photosynthesis because it had the least baking soda. d. Cup 2 had the highest rate of photosynthesis because 5 disks were floating at the end of 10 minutes using a 50 watt light bulb.

The light reactions of photosynthesis supply the Calvin cycle with a. CO2 and ATP. b. sugar and O2. c. ATP and NADPH. d. light energy. e. H2O and NADPH.

Which of the following sequences correctly represents the flow of electrons during photosynthesis? a. H2O → photosystem I → photosystem II b. NADPH → electron transport chain → O2 c. H2O → NADPH → Calvin cycle d. NADPH → chlorophyll → Calvin cycle e. NADPH → O2 → CO2

How is photosynthesis similar in C4 plants and CAM plants? a. In both cases, rubisco is not used to fix carbon initially. b. Both types of plants make sugar without the Calvin cycle. c. In both cases, thylakoids are not involved in photosynthesis. d. In both cases, only photosystem I is used. e. Both types of plants make most of their sugar in the dark.

Which of the following statements is a correct distinction between autotrophs and heterotrophs? a. Only heterotrophs have mitochondria. b. Only heterotrophs require chemical compounds from the environment. c. Only heterotrophs require oxygen. d. Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic. e. Cellular respiration is unique to heterotrophs.

Which of the following does not occur during the Calvin cycle? a. release of oxygen b. oxidation of NADPH c. regeneration of the CO2 acceptor d. consumption of ATP e. carbon fixation

In mechanism, photophosphorylation is most similar to a. substrate-level phosphorylation in glycolysis. b. reduction of NADP+. c. oxidative phosphorylation in cellular respiration. d. carbon fixation. e. the Calvin cycle.

Which process is most directly driven by light energy? a. reduction of NADP+ molecules b. removal of electrons from chlorophyll molecules c. carbon fixation in the stroma d. creation of a pH gradient by pumping protons across the thylakoid membrane e. ATP synthesis

Select the correct molecule that is the main product of the Calvin cycle. a. G3P b. NADPH c. Glucose

What is the basic role of CO2 in photosynthesis? a. CO2 is a source of electrons in the formation of organic molecules. b. CO2 is fixed or incorporated into organic molecules. c. CO2 is taken in by plants as a form of inverse respiration, in which carbon dioxide is "breathed in" and oxygen is "breathed out."

Select the most accurate statement describing the basic function of the light reactions of photosynthesis. a. The basic function of the light reactions of photosynthesis is the production of glucose. b. The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy. c. The basic function of the light reactions of photosynthesis is the trapping of light energy.

Select the correct statement about the Calvin cycle. a. The basic function of the Calvin cycle is the conversion of solar energy to chemical energy. b. The Calvin cycle takes place primarily in the dark. c. The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP.

Why are plants classified as producers? a. Plants are classified as producers because they are at the bottom of the food chain. b. Plants are classified as producers because they produce oxygen. c. Plants are classified as producers because they fix inorganic carbon into organic molecules.

Plants photosynthesize _____. a. only in the dark but respire only in the light b. only in the light but respire in light and dark c. and respire only in the light d. only in the light but respire only in the dark

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 _____. a. ribulose bisphosphate (RuBP) b. glucose c. glyceraldehyde 3-phosphate (G3P) d. O2

What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)? a. An electron is excited. b. Electrons are stripped from NADPH. c. A carboxylation reaction of the Calvin cycle occurs. d. ATP is synthesized from the energy absorbed.

*What wavelengths of light should be used to maximize plant growth with a minimum of energy expenditure? a. UV light b. green light c. a mixture of blue and red light d. full-spectrum white light

Which of the following are directly associated with photosystem I? a. passing electrons to the cytochrome complex b. receiving electrons from the thylakoid membrane electron transport chain c. generation of molecular oxygen d. extraction of hydrogen electrons from the splitting of water

As a research scientist, you measure the amount of ATP and NADPH consumed by the Calvin cycle in 1 hour. You find that 30,000 molecules of ATP were consumed, but only 20,000 molecules of NADPH were consumed. Where did the extra ATP molecules come from? a. cyclic electron flow b. linear electron flow c. photosystem I d. photosystem II

In mitochondria, chemiosmosis moves protons from the intermembrane space into the matrix, whereas in chloroplasts, chemiosmosis moves protons from the _____. a. matrix to the stroma b. stroma to the thylakoid space c. thylakoid space to the stroma d. intermembrane space to the matrix

In photosynthetic cells, synthesis of ATP by the chemiosmotic mechanism occurs during _____. a. respiration only b. neither photosynthesis nor respiration c. photosynthesis and respiration d. photosynthesis only

The accumulation of free oxygen in Earth's atmosphere began with the origin of _____. a. chloroplasts in photosynthetic eukaryotic algae b. life and respiratory metabolism c. land plants d. cyanobacteria using photosystem II

A gardener is concerned that her greenhouse is getting too hot from too much light and seeks to shade her plants with colored translucent plastic sheets, the color of which allows passage of only that wavelength. What color should she use to reduce overall light energy but still maximize plant growth? a. orange b. blue c. green d. Any color will work equally well.

Where does the Calvin cycle take place? a. interior of the thylakoid (thylakoid space) b. stroma of the chloroplast c. thylakoid membrane d. outer membrane of the chloroplast

Which of the following does NOT occur during the Calvin cycle? a. oxidation of NADPH b. regeneration of the CO2 acceptor c. release of oxygen d. consumption of ATP