Question 1

Which scientist disproved the theory of spontaneous generation by demonstrating that maggots do not arise from meat unless flies lay eggs on it?

Accepted Answer

Francesco Redi

Question 2

Which of the following is NOT one of Koch's postulates?

Accepted Answer

The microorganism must be able to survive outside the host for at least 24 hours.

Question 3

Given the atomic number and atomic weight of oxygen ($$8$$ and $$15.999$$ respectively), how many neutrons does a typical oxygen atom have?

Accepted Answer

$$8 ($$since $$15.999 - 8 \approx 8)$$

Question 4

Which type of chemical bond is the strongest in biological systems?

Accepted Answer

Covalent bond

Question 5

Which of the following best describes the difference between synthesis and decomposition reactions?

Accepted Answer

Synthesis reactions build larger molecules from smaller ones; decomposition reactions break molecules into smaller parts.

Question 6

Which of the following is a macromolecule that serves as the main energy source for cells?

Accepted Answer

Carbohydrate

Question 7

Denaturation of a protein most directly affects which aspect of the protein?

Accepted Answer

Its secondary and tertiary structure

Question 8

Which of the following is a key difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have membrane-bound organelles; prokaryotic cells do not.

Question 9

Which of the following statements about Gram-positive and Gram-negative cell walls is correct?

Accepted Answer

Gram-positive cell walls contain a thick layer of peptidoglycan.

Question 10

Which of the following is NOT a type of passive transport across a bacterial cell membrane?

Accepted Answer

Active transport

Question 11

If a bacterial cell is placed in a hypotonic solution and lacks a cell wall, what is the most likely outcome?

Accepted Answer

The cell will burst due to water influx.

Question 12

Which organelle is responsible for ATP production in eukaryotic cells?

Accepted Answer

Mitochondria

Question 13

Which of the following best describes the function of ribosomes?

Accepted Answer

Protein synthesis

Question 14

Which type of microscopy allows visualization of living cells in high contrast without staining?

Accepted Answer

Phase-contrast microscopy

Question 15

Which of the following statements about enzymes is correct?

Accepted Answer

Enzymes lower the activation energy of a reaction.

Question 16

Which of the following best describes competitive inhibition of an enzyme?

Accepted Answer

An inhibitor binds to the active site, preventing substrate binding.

Question 17

During glycolysis, how many net ATP molecules are produced per molecule of glucose?

Accepted Answer

$$2$$

Question 18

Which molecule is the final electron acceptor in aerobic respiration?

Accepted Answer

Oxygen ($$O_2)$$

Question 19

Which process produces the most ATP per glucose molecule?

Accepted Answer

Aerobic respiration

Question 20

Which of the following is a product of the Calvin Benson cycle?

Accepted Answer

Glucose

Microbiology Study Guide: Chapters 1–5 Core Concepts

Study Guide - Practice Questions