Question 1

CAM plants keep stomata closed in daytime,thus reducing loss of water.They can do this because they

Accepted Answer

A) fix CO2 into organic acids during the night when temperatures are cooler. 
B) fix CO2 into organic acids in the bundle-sheath cells,which do not rely on stomata. 
C) fix CO2 into organic acids in the mesophyll cells,which do not rely on stomata. 
D) fix CO2 into by combining it with RuBP in the Calvin cycle. 
E) obtain CO2 through their roots during the day. 
A) fix CO2 into organic acids during the night when temperatures are cooler. 
B) fix CO2 into organic acids in the bundle-sheath cells,which do not rely on stomata. 
C) fix CO2 into organic acids in the mesophyll cells,which do not rely on stomata. 
D) fix CO2 into by combining it with RuBP in the Calvin cycle. 
E) obtain CO2 through their roots during the day.

Question 2

Why are C4 plants able to photosynthesize with no apparent photorespiration?

Accepted Answer

A) They do not participate in the Calvin cycle. 
B) They keep their stomata open most of the time in hot,dry climates,which allows for water loss to prevent photorespiration. 
C) They keep their stomata closed most of the time in hot,dry climates,which conserves water and oxygen to inhibit photorespiration. 
D) They do not use rubisco to fix CO2. 
E) They exclude oxygen from their tissues. 
A) They do not participate in the Calvin cycle. 
B) They keep their stomata open most of the time in hot,dry climates,which allows for water loss to prevent photorespiration. 
C) They keep their stomata closed most of the time in hot,dry climates,which conserves water and oxygen to inhibit photorespiration. 
D) They do not use rubisco to fix CO2. 
E) They exclude oxygen from their tissues.

Question 3

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

Accepted Answer

A) The light reactions provide ATP and NADPH to the Calvin cycle,and the Calvin cycle returns ADP,℗i,and NADP+ to the light reactions. 
B) The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle,and the Calvin cycle provides water and electrons to the light reactions. 
C) The light reactions supply the Calvin cycle with CO2 to produce sugars,and the Calvin cycle supplies the light reactions with sugars to produce ATP. 
D) The light reactions provide the Calvin cycle with oxygen for carbon fixation,and the Calvin cycle provides the light reactions with sugars to produce ATP. 
A) The light reactions provide ATP and NADPH to the Calvin cycle,and the Calvin cycle returns ADP,℗i,and NADP+ to the light reactions. 
B) The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle,and the Calvin cycle provides water and electrons to the light reactions. 
C) The light reactions supply the Calvin cycle with CO2 to produce sugars,and the Calvin cycle supplies the light reactions with sugars to produce ATP. 
D) The light reactions provide the Calvin cycle with oxygen for carbon fixation,and the Calvin cycle provides the light reactions with sugars to produce ATP.

Question 4

Which of the following molecules are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

Accepted Answer

A) CO2 and glucose 
B) H2O and O2 
C) ADP,℗i,and NADP+ 
D) electrons and H+ 
E) ATP and NADPH 
A) CO2 and glucose 
B) H2O and O2 
C) ADP,℗i,and NADP+ 
D) electrons and H+ 
E) ATP and NADPH

Question 5

In photosynthetic cells,which reactions is (are)responsible for the synthesis of ATP by chemiosmosis?

Accepted Answer

A) photosynthesis only 
B) cellular respiration only 
C) both photosynthesis and cellular respiration 
D) cyclic photophosphorylation only 
A) photosynthesis only 
B) cellular respiration only 
C) both photosynthesis and cellular respiration 
D) cyclic photophosphorylation only

Question 6

Where is the electron transport chain associated with photophosphorylation located in plant cells?

Accepted Answer

A) thylakoid membranes of chloroplasts 
B) stroma of chloroplasts 
C) outer membrane of chloroplasts 
D) inner membrane of mitochondria 
A) thylakoid membranes of chloroplasts 
B) stroma of chloroplasts 
C) outer membrane of chloroplasts 
D) inner membrane of mitochondria

Question 7

A reduction in the amount of NADP+ available in plant cells in the light will ultimately result in which of the following effects?

Accepted Answer

A) an increase in the rate of the Calvin cycle 
B) a decrease in the rate of linear electron flow 
C) a decrease in the rate of cyclic electron flow 
D) an increase in the rate of oxygen production 
A) an increase in the rate of the Calvin cycle 
B) a decrease in the rate of linear electron flow 
C) a decrease in the rate of cyclic electron flow 
D) an increase in the rate of oxygen production

Question 8

P680+ is often considered the strongest biological oxidizing agent.Given its function,why is this necessary?

Accepted Answer

A) It is the receptor for the most excited electrons in either photosystem. 
B) It is the molecule that transfers electrons to the photosynthetic electron transport chain. 
C) It transfers its electrons directly to NADP+ to produce NADPH. 
D) It obtains electrons from the oxygen atom in a water molecule,so it must have a greater affinity for electrons than oxygen has. 
E) It has a positive charge. 
A) It is the receptor for the most excited electrons in either photosystem. 
B) It is the molecule that transfers electrons to the photosynthetic electron transport chain. 
C) It transfers its electrons directly to NADP+ to produce NADPH. 
D) It obtains electrons from the oxygen atom in a water molecule,so it must have a greater affinity for electrons than oxygen has. 
E) It has a positive charge.

Question 9

How is photosynthesis similar in C4 plants and CAM plants?

Accepted Answer

A) In both cases,electron transport is not used. 
B) Both types of plants make sugar without the Calvin cycle. 
C) In both cases,rubisco is not used to fix carbon initially. 
D) Both types of plants make most of their sugar in the dark. 
A) In both cases,electron transport is not used. 
B) Both types of plants make sugar without the Calvin cycle. 
C) In both cases,rubisco is not used to fix carbon initially. 
D) Both types of plants make most of their sugar in the dark.

Question 10

Which process is most directly driven by light energy?

Accepted Answer

A) creation of a pH gradient by pumping protons across the thylakoid membrane 
B) reduction of NADP+ molecules 
C) removal of electrons from chlorophyll molecules 
D) ATP synthesis 
A) creation of a pH gradient by pumping protons across the thylakoid membrane 
B) reduction of NADP+ molecules 
C) removal of electrons from chlorophyll molecules 
D) ATP synthesis

Question 11

Theodor W.Engelmann illuminated a filament of algae with light that passed through a prism,thus exposing different segments of algae to different wavelengths of light.He added aerobic bacteria and then noted in which areas the bacteria congregated.He found that the largest groups were found in the areas illuminated by the red and blue light.What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

Accepted Answer

A) Bacteria congregated in these areas due to a local increase in temperature generated by illumination by red and blue light. 
B) Bacteria released excess carbon dioxide in these areas. 
C) Bacteria congregated in these areas because they are attracted to red and blue light. 
D) Bacteria congregated in these areas because they were the areas where the most oxygen was released by the algae. 
A) Bacteria congregated in these areas due to a local increase in temperature generated by illumination by red and blue light. 
B) Bacteria released excess carbon dioxide in these areas. 
C) Bacteria congregated in these areas because they are attracted to red and blue light. 
D) Bacteria congregated in these areas because they were the areas where the most oxygen was released by the algae.

Question 12

Chemiosmosis in chloroplasts involves which of the following processes?

Accepted Answer

A) establishment of a proton gradient across the thylakoid membrane 
B) diffusion of electrons through the thylakoid membrane 
C) reduction of water to produce oxygen 
D) formation of glucose from carbon dioxide 
A) establishment of a proton gradient across the thylakoid membrane 
B) diffusion of electrons through the thylakoid membrane 
C) reduction of water to produce oxygen 
D) formation of glucose from carbon dioxide

Question 13

The enzyme rubisco plays a critical role in carbon fixation in which of the following types of plants?

Accepted Answer

A) C3 plants only 
B) C4 plants only 
C) C3 and C4 plants only 
D) C4 and CAM plants only 
E) C3,C4,and CAM plants 
A) C3 plants only 
B) C4 plants only 
C) C3 and C4 plants only 
D) C4 and CAM plants only 
E) C3,C4,and CAM plants

Question 14

Where do the enzymatic reactions of the Calvin cycle take place?

Accepted Answer

A) stroma of the chloroplast 
B) thylakoid membranes 
C) matrix of the mitochondria 
D) thylakoid space 
A) stroma of the chloroplast 
B) thylakoid membranes 
C) matrix of the mitochondria 
D) thylakoid space

Question 15

Photophosphorylation in photosynthesis is most similar to which of the following processes associated with cellular respiration?

Accepted Answer

A) substrate-level phosphorylation in glycolysis 
B) pyruvate oxidation in the production of acetyl-CoA 
C) oxidation of NADH in anerobic fermentation 
D) oxidative phosphorylation in mitochondria 
A) substrate-level phosphorylation in glycolysis 
B) pyruvate oxidation in the production of acetyl-CoA 
C) oxidation of NADH in anerobic fermentation 
D) oxidative phosphorylation in mitochondria

Question 16

What is the primary function of cyclic electron flow?

Accepted Answer

A) to produce additional NADPH 
B) to produce additional ATP 
C) to produce additional oxygen 
D) to produce additional carbon dioxide 
A) to produce additional NADPH 
B) to produce additional ATP 
C) to produce additional oxygen 
D) to produce additional carbon dioxide

Question 17

What is the primary function of the pigment molecules in a light-harvesting complex?

Accepted Answer

A) to split water and release oxygen to the reaction-center chlorophyll 
B) to transfer light energy to the reaction-center chlorophyll 
C) to synthesize ATP from ADP and ℗i 
D) to transfer electrons to the primary electron acceptor 
A) to split water and release oxygen to the reaction-center chlorophyll 
B) to transfer light energy to the reaction-center chlorophyll 
C) to synthesize ATP from ADP and ℗i 
D) to transfer electrons to the primary electron acceptor

Question 18

Which of the following statements correctly describes a reaction associated with photosystem II?

Accepted Answer

A) Light energy excites electrons in the thylakoid membrane electron transport chain. 
B) Electrons released from the P680 chlorophyll are replaced by electrons derived from water. 
C) The P680 chlorophyll donates a pair of electrons directly to NADP+,producing NADPH. 
D) Electrons are passed from the P680 chlorophyll to oxygen (O2). 
A) Light energy excites electrons in the thylakoid membrane electron transport chain. 
B) Electrons released from the P680 chlorophyll are replaced by electrons derived from water. 
C) The P680 chlorophyll donates a pair of electrons directly to NADP+,producing NADPH. 
D) Electrons are passed from the P680 chlorophyll to oxygen (O2).

Question 19

If plants are grown in the light with CO2 containing a radioactive isotope of oxygen (18O),subsequent analysis will show that 18O incorporated in organic molecules first appears in

Accepted Answer

A) the thylakoid space. 
B) the thylakoid membranes. 
C) the stroma. 
D) mitochondria. 
A) the thylakoid space. 
B) the thylakoid membranes. 
C) the stroma. 
D) mitochondria.

Question 20

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

Accepted Answer

A) Autotrophs,but not heterotrophs,can nourish themselves beginning with CO2 and other nutrients that are inorganic. 
B) Only heterotrophs require chemical compounds from the environment. 
C) Cellular respiration is unique to heterotrophs. 
D) Only heterotrophs have mitochondria. 
A) Autotrophs,but not heterotrophs,can nourish themselves beginning with CO2 and other nutrients that are inorganic. 
B) Only heterotrophs require chemical compounds from the environment. 
C) Cellular respiration is unique to heterotrophs. 
D) Only heterotrophs have mitochondria.

Exam 8: Photosynthesis

CAM plants keep stomata closed in daytime,thus reducing loss of water.They can do this because they

Why are C4 plants able to photosynthesize with no apparent photorespiration?

Which of the following statements best represents the relationships between the light reactions and the Calvin cycle?

Which of the following molecules are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?

In photosynthetic cells,which reactions is (are)responsible for the synthesis of ATP by chemiosmosis?

Where is the electron transport chain associated with photophosphorylation located in plant cells?

A reduction in the amount of NADP+ available in plant cells in the light will ultimately result in which of the following effects?

P680+ is often considered the strongest biological oxidizing agent.Given its function,why is this necessary?

How is photosynthesis similar in C4 plants and CAM plants?

Which process is most directly driven by light energy?

Chemiosmosis in chloroplasts involves which of the following processes?

The enzyme rubisco plays a critical role in carbon fixation in which of the following types of plants?

Where do the enzymatic reactions of the Calvin cycle take place?

Photophosphorylation in photosynthesis is most similar to which of the following processes associated with cellular respiration?

What is the primary function of cyclic electron flow?

What is the primary function of the pigment molecules in a light-harvesting complex?

Which of the following statements correctly describes a reaction associated with photosystem II?

If plants are grown in the light with CO2 containing a radioactive isotope of oxygen (18O),subsequent analysis will show that 18O incorporated in organic molecules first appears in

Which of the following statements is a correct distinction between autotrophs and heterotrophs?

Introduction: Evolution and the Foundations of Biology

The Chemical Context of Life

Carbon and the Molecular Diversity of Life

A Tour of the Cell

Membrane Transport and Cell Signaling

An Introduction to Metabolism

Cellular Respiration and Fermentation

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Development,stem Cells,and Cancer

Viruses

Genomes and Their Evolution

Descent With Modification

Phylogeny

The Evolution of Populations

The Origin of Species

Broad Patterns of Evolution

Early Life and the Diversification of Prokaryotes

The Origin and Diversification of Eukaryotes

The Colonization of Land by Plants and Fungi

The Rise of Animal Diversity

Plant Structure and Growth

Resource Acquisition,nutrition,and Transport in Vascular Plants

Reproduction and Domestication of Flowering Plants

Plant Responses to Internal and External Signals

Homeostasis and Endocrine Signaling

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Reproduction and Development

Neurons,synapses,and Signaling

Nervous and Sensory Systems

Motor Mechanisms and Behavior

Population Ecology and the Distribution of Organisms

Ecological Communities

Ecosystems and Energy

Conservation Biology and Global Change

Filters

Why are C₄ plants able to photosynthesize with no apparent photorespiration?

A reduction in the amount of NADP⁺ available in plant cells in the light will ultimately result in which of the following effects?

P680⁺ is often considered the strongest biological oxidizing agent.Given its function,why is this necessary?

How is photosynthesis similar in C₄ plants and CAM plants?

If plants are grown in the light with CO₂ containing a radioactive isotope of oxygen (¹⁸O),subsequent analysis will show that ¹⁸O incorporated in organic molecules first appears in