AP Biology : AP Biology

Study concepts, example questions & explanations for AP Biology

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Example Questions

Example Question #4 : Understand Light Dependent Reactions

What products of the light dependent reaction are necessary for the light independent reaction to occur?

Possible Answers:

ATP and NADP+

ATP and NAPH

ADP and NADP+

ADP and NADP+

Correct answer:

ATP and NAPH

Explanation:

 ATP and NADPH are produced during the light dependent reaction, and are reactants necessary for the light independent reaction (Calvin Cycle) to occur. During the light independent reaction, ATP and NADPH are used to convert phosphoglycerate molecules (PGA) to glyceraldehyde-3-phosphate molecules (G3P). G3P is then used to produce glucose.

Example Question #8 : Understand Light Dependent Reactions

Which is true of light dependent reactions?

Possible Answers:

NADP+ is a product

 is a reactant

GTP is a reactant

ATP is a product

Correct answer:

ATP is a product

Explanation:

Light dependent reactions convert solar energy to chemical energy (in the form of ATP and NADPH). Sunlight and H2O are the reactant of the light dependent reaction. The sunlight is captured by photosystem II, and is used to excite electrons. Splitting of H2O produces hydrogen ions used to establish the proton gradient, and electrons produced replace the electrons transferred to the primary electron acceptor.

Example Question #101 : Plant Biology

Where is the electron transport chain located, for the light dependent reaction?

Possible Answers:

thylakoid lumen

thylakoid membrane

mitochondrial membrane

stroma

Correct answer:

thylakoid membrane

Explanation:

 The electron transport chain is located on the thylakoid membrane. The proton gradient is established through pumping hydrogen ions into the interior of the thylakoid (lumen).

Example Question #1 : Understand Inputs And Outputs, Purpose

Which of the following is not a reactant used in the process of photosynthesis?

Possible Answers:

O2

CO2

Light energy

H2O

Correct answer:

O2

Explanation:

The process of photosynthesis can be summarized by the following equation.

H2O, CO2, and light energy are thus reactants of photosynthesis, while O2 is only a product.

Example Question #2 : Understand Inputs And Outputs, Purpose

What are the products of photosynthesis?

Possible Answers:

Oxygen and carbon dioxide

Water and carbon dioxide

Glucose and oxygen

Light and glucose

Carbon dioxide and light

Correct answer:

Glucose and oxygen

Explanation:

The photosynthesis equation can be written as:

From this equation, we can see that plants take in carbon dioxide, water, and light energy as reactants and produce glucose and oxygen as products.

Example Question #3 : Understand Inputs And Outputs, Purpose

Some organisms, such as green plants, are capable of obtaining energy directly from photosynthesis. These organisms are termed __________.

Possible Answers:

homotrophs

primary consumers

heterotrophs

herbivores

autotrophs

Correct answer:

autotrophs

Explanation:

Autotrophs are organisms that produce complex organic compounds from substances present in the surroundings. These organisms may do this through the use of energy from light or from inorganic chemical reactions.

In contrast, heterotrophs require organic input in order to generate biological compounds and are unable to use light or inorganic materials for energy.

Example Question #1 : Understand Inputs And Outputs, Purpose

Which of the following is true of photosynthesis? 

Possible Answers:

Water is reduced

Carbon dioxide is oxidized

Electrons decrease in potential energy as they move from water to sugar

Carbon dioxide is reduced

The process requires no energy

Correct answer:

Carbon dioxide is reduced

Explanation:

Photosynthesis occurs in the chloroplasts of plant cells, where carbon dioxide is reduced and water is oxidized to create sugar. During this process electrons demonstrate increased potential energy as they move from water to sugar. The process requires an initial energy input, derived from photons.

Example Question #4 : Understand Inputs And Outputs, Purpose

Organisms that make their organic molecules from inorganic raw materials obtained from the surrounding environment are called __________.

Possible Answers:

heterotrophs

auxotrophs

plants

autotrophs

Correct answer:

autotrophs

Explanation:

Autotrophs create organic material from inorganic materials. Autotrophs are self-feeders in that they do not consume other organic materials but rather create their own organic materials. Plants and other photosynthetic organisms are examples of autotrophs.   

Example Question #5 : Understand Inputs And Outputs, Purpose

Plants are an example of which of the following categories of organisms?

Possible Answers:

Autotrophs

Heterotrophs

Chemoautotrophs

Biosphere consumers

Correct answer:

Autotrophs

Explanation:

Plants are an example of autotrophs. Autotrophs sustain themselves without consuming other organic material. Instead they create organic material from inorganic materials.

Example Question #6 : Understand Inputs And Outputs, Purpose

Which of the following are referred to as the major sites of photosynthesis in most plants?

Possible Answers:

Roots

Flowers

Stems

Leaves

Correct answer:

Leaves

Explanation:

The leaves are the major sites of photosynthesis in most plants. The chloroplasts are located in the mesophyll—interior tissues of the leaves—and are the primary sites of photosynthesis.

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