BIO 101 Tues/Thur Practice Questions

What pigment in plants reflects green light, giving plants their color?

• Chlorophyll a

• Carotenoids

• Chlorophyll b

• Xanthophyll

Answer explanation

Chlorophyll a is the primary pigment in plants that reflects green light, which is why plants appear green. It plays a crucial role in photosynthesis, absorbing light energy for the process.

Tags

NGSS.MS-LS1-6

In the light-dependent reactions, what molecule is split to provide electrons?

• Oxygen

• Water

• Glucose

• Carbon dioxide

Answer explanation

In the light-dependent reactions of photosynthesis, water is split to release electrons. This process, known as photolysis, provides the necessary electrons for the electron transport chain, making water the correct answer.

What happens to electrons in photosystem I after they are excited by light?

• They are used to make ATP

• They are passed to NADP+ to form NADPH

• They are transported to photosystem II

• They return to the ground state

Answer explanation

In photosystem I, excited electrons are transferred to NADP+, reducing it to NADPH. This process is crucial for the light-dependent reactions of photosynthesis, as NADPH is used in the Calvin cycle for sugar synthesis.

Tags

NGSS.HS-LS1-5

What molecule acts as the primary energy carrier from the light reactions to the Calvin cycle?

• ATP

• NADPH

• FADH2

• NADH

Answer explanation

NADPH is the primary energy carrier from the light reactions to the Calvin cycle, providing the reducing power needed for the conversion of carbon dioxide into glucose.

Tags

NGSS.HS-LS1-5

Which process does not require light but is dependent on the products of the light-dependent reactions?

• Cellular respiration

• Calvin cycle

• Photorespiration

• Photolysis

Answer explanation

The Calvin cycle does not require light directly; instead, it uses ATP and NADPH produced in the light-dependent reactions to convert carbon dioxide into glucose.

Where does oxidative phosphorylation occur in eukaryotic cells?

• Cytoplasm

• Mitochondrial cristae

• Plasma membrane

• Ribosome

Answer explanation

Oxidative phosphorylation occurs in the mitochondrial cristae, which are the inner membrane folds of mitochondria. This is where ATP is produced through the electron transport chain and chemiosmosis.

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

What is the net gain of ATP from glycolysis?

• 1 ATP

• 2 ATP

• 4 ATP

• 6 ATP

Answer explanation

Glycolysis produces a net gain of 2 ATP. Although 4 ATP are generated, 2 ATP are consumed in the initial steps, resulting in a net gain of 2 ATP.

Tags

NGSS.HS-LS1-7

Which of the following is produced during the link reaction (pyruvate oxidation)?

• Acetyl-CoA

• Glucose

• Pyruvate

• ATP

Answer explanation

During the link reaction, pyruvate is converted into acetyl-CoA, which is essential for entering the citric acid cycle. Glucose and ATP are not produced in this step, making acetyl-CoA the correct answer.

Tags

NGSS.HS-LS1-7

What happens during the citric acid cycle (Krebs cycle)?

• Acetyl-CoA combines with oxaloacetate to produce citrate

• Glucose is broken down into pyruvate

• Oxygen is consumed

• NADH is converted to ATP

Answer explanation

During the citric acid cycle, Acetyl-CoA combines with oxaloacetate to form citrate, marking the cycle's initiation. This process is crucial for energy production, while glucose breakdown occurs earlier in glycolysis.

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

Which molecule donates electrons to the electron transport chain in cellular respiration?

• NADH

• FADH2

• Oxygen

• Water

Answer explanation

NADH donates electrons to the electron transport chain during cellular respiration, facilitating ATP production. FADH2 also donates electrons but at a later stage. Oxygen is the final electron acceptor, while water is a product.

Tags

NGSS.HS-LS1-7