ATDH - Admission Test for Dental Hygiene General Biology Concepts Questions and Answers

Question 1

In eukaryotic cells, which organelle is primarily responsible for generating the majority of the cell's supply of adenosine triphosphate (ATP) through aerobic respiration?

Accepted Answer

Mitochondrion

Answer

The mitochondrion is known as the 'powerhouse' of the cell because it is the site of the Krebs cycle and oxidative phosphorylation, which together produce the vast majority of cellular ATP.

Question 2

A patient uses a highly concentrated saline (saltwater) rinse, creating a hypertonic environment in the oral cavity. What is the most likely effect on bacterial cells present on the mucosal surfaces?

Accepted Answer

The cells will lose water and shrink.

Answer

In a hypertonic solution, the solute concentration outside the cell is higher than inside. Due to osmosis, water moves from an area of higher water concentration (inside the cell) to an area of lower water concentration (outside the cell), causing the cell to lose water and shrink, a process called plasmolysis.

Question 3

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

Accepted Answer

To act as catalysts that increase the rate of reactions.

Answer

Enzymes are biological catalysts that lower the activation energy required for a chemical reaction to proceed. This significantly speeds up the rate at which the reaction occurs without the enzyme being consumed in the process.

Question 4

A key structural difference between deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) is the type of sugar present in their nucleotide backbones. What are the respective sugars found in DNA and RNA?

Accepted Answer

Deoxyribose in DNA, Ribose in RNA

Answer

The names of the nucleic acids themselves indicate their sugar components. DNA contains the pentose sugar deoxyribose, while RNA contains the pentose sugar ribose. The key difference is that deoxyribose lacks an oxygen atom at the 2' carbon position that is present in ribose.

Question 5

Many pathogenic bacteria that contribute to periodontal disease thrive in the low-oxygen environment of subgingival pockets. These bacteria primarily generate energy through which metabolic process?

Accepted Answer

Anaerobic respiration

Answer

Anaerobic respiration is a form of cellular respiration that generates energy in the absence of oxygen. This process is characteristic of obligate and facultative anaerobes that colonize deep periodontal pockets where oxygen is scarce.

ATDH - Admission Test for Dental Hygiene Practice Test

ATDH - Admission Test for Dental Hygiene Practice Test

ATDH - Admission Test for Dental Hygiene General Biology Concepts Questions and Answers