Question 1

Which of the following best describes the fluid mosaic model of the plasma membrane?

Accepted Answer

A dynamic structure with proteins and lipids that can move laterally within the layer, allowing flexibility and selective permeability.

Question 2

A red blood cell is placed in a solution with a lower solute concentration than its cytoplasm. What will happen to the cell, and what is the term for this type of solution?

Accepted Answer

The cell will swell and possibly burst; the solution is hypotonic.

Question 3

Which of the following substances can most easily diffuse across the hydrophobic core of a plasma membrane without the help of transport proteins?

Accepted Answer

Small nonpolar molecules like $$O_2$$

Question 4

The sodium-potassium pump is an example of which type of membrane transport, and what is its main function?

Accepted Answer

Active transport; to move $$Na^+$$ out of and $$K^+$$ into the cell against their concentration gradients

Question 5

Which process involves the cell engulfing large particles or even whole cells, and what is this process called?

Accepted Answer

Phagocytosis; the cell engulfs large particles or cells

Question 6

According to the first law of thermodynamics, which of the following statements is correct?

Accepted Answer

Energy can be transferred and transformed, but it cannot be created or destroyed.

Question 7

A chemical reaction has a negative $$\Delta G. $$What does this indicate about the reaction?

Accepted Answer

The reaction is exergonic and will occur spontaneously.

Question 8

Which of the following best describes the role of enzymes in biological reactions?

Accepted Answer

Enzymes lower the activation energy, speeding up the reaction without being consumed.

Question 9

Where do the three main stages of cellular respiration occur in a eukaryotic cell?

Accepted Answer

Glycolysis in the cytosol, citric acid cycle in the mitochondrial matrix, oxidative phosphorylation on the inner mitochondrial membrane

Question 10

During aerobic respiration, what is the final electron acceptor in the electron transport chain?

Accepted Answer

Oxygen ($$O_2)$$

Question 11

Which of the following best explains how chemiosmosis drives ATP synthesis in mitochondria?

Accepted Answer

Protons flow down their gradient through ATP synthase, providing energy to convert ADP and $$P_i to $$ATP.

Question 12

Which of the following is a key difference between lactic acid fermentation and alcohol fermentation?

Accepted Answer

Alcohol fermentation produces ethanol and $$CO_2$$, while lactic acid fermentation produces lactate and no $$CO_2.$$

Question 13

Which of the following statements correctly distinguishes autotrophs from heterotrophs?

Accepted Answer

Autotrophs produce their own organic molecules from inorganic sources, while heterotrophs must consume organic molecules.

Question 14

Where do the light reactions and the Calvin cycle take place in a chloroplast?

Accepted Answer

Light reactions in the thylakoid membrane; Calvin cycle in the stroma

Question 15

Which sequence correctly traces the path of electrons during the light reactions of photosynthesis?

Accepted Answer

Water $$\rightarrow$$ Photosystem II $$\rightarrow$$ Photosystem I $$\rightarrow$$ NADP^+$

Question 16

Which adaptation allows CAM and C4 plants to minimize water loss while still performing photosynthesis?

Accepted Answer

They open their stomata only at night or use spatial separation of carbon fixation and the Calvin cycle.

Question 17

A solution contains 0.5 M glucose and 0.5 M NaCl. What is the total solute concentration in terms of osmolarity?

Accepted Answer

$$1.5$$ osmolar

Question 18

If a cell is placed in a hypertonic solution, what will happen to the cell and why?

Accepted Answer

The cell will shrink because water leaves the cell.

Question 19

Which of the following best describes receptor-mediated endocytosis?

Accepted Answer

The cell engulfs specific molecules bound to receptors on the plasma membrane.

Question 20

Which of the following is true about the relationship between the change in free energy ($$\Delta G) $$and the equilibrium constant ($$K_{eq}) $$for a reaction?

Accepted Answer

$$\Delta G is $$negative when $$K_{eq} \u003e 1$$

General Biology Exam Study Guide: Membranes, Metabolism, Respiration, and Photosynthesis

Guida di studio - Domande di pratica

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