Mixed Deck — All ATDH Topics Flashcards

The volume of a cylinder with radius 4 cm and height 10 cm is approximately: (Use π ≈ 3.14)

Answer: 502.4 cm³

Volume of a cylinder = π × r² × h = 3.14 × 16 × 10 = 502.4 cm³.

A right angle measures exactly:

Answer: 90°

A right angle is exactly 90° and is indicated by a small square symbol in geometric diagrams.

In the geometric shape below, four interior angles are indicated. Which of the labeled angles is the smallest?

Answer: Angle B

By inspecting the four labeled angles within the shape, Angle B is the most acute or 'sharpest' corner. Angle C is a right angle (90 degrees). Angles A and D are both obtuse, making them significantly larger than Angle B.

A dental hygienist mixes a 2% fluoride solution with a 10% fluoride solution to create 80 ml of a 5% fluoride solution. How many milliliters of the 10% solution are needed?

Answer: 30 ml

Let x be the amount of the 2% solution and y be the amount of the 10% solution. The two equations are x + y = 80 (total volume) and 0.02x + 0.10y = 0.05 * 80 (total fluoride amount). From the first equation, x = 80 - y. Substitute this into the second equation: 0.02(80 - y) + 0.10y = 4. This simplifies to 1.6 - 0.02y + 0.10y = 4. Then, 0.08y = 2.4. Solving for y gives y = 30 ml.

A dental hygienist is examining the angulation of different periodontal probes. Which of the following instruments shows the largest angle?

Answer: Instrument D

By visually comparing the four angles, Angle D is the most open, making it the largest (most obtuse) angle among the choices. Angle A is the smallest, followed by C, then B, with D being the largest.

Which hormone is secreted by the pancreatic beta cells to lower blood glucose levels?

Answer: Insulin

Insulin, released by beta cells of the islets of Langerhans, promotes glucose uptake by cells, lowering blood glucose.

During DNA replication, one enzyme is responsible for unwinding the double helix by breaking the hydrogen bonds between the nucleotide base pairs. Which enzyme performs this critical function?

Answer: DNA Helicase

DNA Helicase is the enzyme that 'unzips' the two strands of the DNA double helix, creating the replication fork where replication can begin. DNA Polymerase then synthesizes the new strands, and DNA Ligase joins fragments together.

Which of the following compounds is an ester?

Answer: CH3COOCH3

CH3COOCH3 (methyl acetate) is an ester, identifiable by the -COO- linkage formed from a carboxylic acid reacting with an alcohol.

The valleys, on the other hand, present daunting challenges—submerged under oceans, many of these valleys remain elusive to all but a tiny number of daring, highly motivated explorers. What is the meaning of the word “daunting” as it is used in this sentence?

Answer: Formidable

Explanation: The word "daunting" means intimidating or challenging, suggesting something that is difficult to overcome. "Formidable" is a synonym that conveys a similar meaning, indicating something that inspires fear or respect due to its size, power, or difficulty. In this context, "daunting challenges" refers to the difficult and intimidating nature of exploring the submerged valleys.

What is the surface area of a cube with an edge length of 3 inches?

Answer: 54 in²

A cube has 6 faces; surface area = 6 × s² = 6 × 3² = 6 × 9 = 54 in².

A passage describes the formation of dental biofilm: "The initial phase involves the adhesion of a conditioning film, known as the acquired pellicle, to the tooth surface. This acellular layer is rapidly colonized by early bacterial settlers, predominantly streptococci. Over time, a complex, multi-species community develops through coaggregation, creating a mature biofilm with a sophisticated structure that protects the embedded bacteria from antimicrobial agents and host defenses." According to the passage, which of the following is the first step in the formation of dental biofilm?

Answer: The formation of the acquired pellicle.

The text outlines a clear sequence of events. It states, 'The initial phase involves the adhesion of a conditioning film, known as the acquired pellicle...' This happens before the bacterial colonization and subsequent maturation of the biofilm.

What is the formula for sulfuric acid?

Answer: H2SO4

Explanation: Sulfuric acid is represented by the chemical formula H2SO4. It is a strong mineral acid with the chemical formula H2SO4. It is soluble in water at all concentrations, and its aqueous solution is known as "battery acid" or "diluted sulfuric acid." It is one of the most important industrial chemicals, primarily used in the production of fertilizers, explosives, detergents, and various other chemicals.

The Mariana Trench is the result of an ancient geological confrontation—a collision between two massive plates in the planet’s crust—called a subduction. What is the author’s purpose for including the phrase: “a collision between two massive plates in the planet’s crust”?

Answer: To communicate the meaning of a scientific term

Explanation: The author's purpose for including the phrase "a collision between two massive plates in the planet’s crust" is to communicate the meaning of a scientific term, specifically, the geological process that led to the formation of the Mariana Trench.

A study summary explains a new dental material: "The novel composite resin incorporates bioactive glass particles that release calcium and phosphate ions in response to a low pH environment, such as that occurring during an acid attack from plaque bacteria. This localized ion release is designed to promote remineralization of adjacent tooth enamel." A patient with a high-sugar diet and a history of multiple cavities receives a restoration with this new material. Based on the passage, what is the most likely benefit for this specific patient?

Answer: The material will help strengthen the tooth structure surrounding the filling during acid challenges.

The passage states the material releases ions to 'promote remineralization of adjacent tooth enamel' in response to low pH (acid attacks). A patient with a high-sugar diet is prone to such acid attacks. Therefore, the material's ability to help strengthen the surrounding tooth structure is the direct, applicable benefit described.

A cell needs to move calcium ions from the cytoplasm, where the concentration is low, into the sarcoplasmic reticulum, where the concentration is high. This process requires energy. Which mechanism of cellular transport is being used?

Answer: Active Transport

Active transport is the movement of substances across a cell membrane against their concentration gradient (from a region of lower concentration to a region of higher concentration). This process requires cellular energy, typically in the form of ATP. The other options are forms of passive transport, which do not require energy.

Choose the word that correctly completes the following sentence: 'The dental hygienist gave the patient expert _______ on how to improve their brushing technique.'

Answer: advice

'Advice' is a noun meaning 'guidance or recommendations.' 'Advise' is a verb meaning 'to offer suggestions.' In this sentence, the hygienist is giving something (a noun) to the patient. Therefore, 'advice' is the correct choice.

Which organ system is primarily responsible for regulating body temperature, fluid balance, and protection against pathogens?

Answer: Integumentary system

The integumentary system (skin, hair, nails, glands) regulates body temperature, prevents water loss, and acts as the first line of defense.

Review the four angles presented. Rank them in order from largest to smallest.

Answer: A, D, C, B

Angle A is the largest, being the only obtuse angle. Angle D is the next largest, appearing to be close to a right angle. Angle C is smaller than D, and Angle B is the most acute and therefore the smallest. The correct ranking from largest to smallest is A, D, C, B.

Read this excerpt from a letter to a patient. Your improved cholesterol test results are __________, and we encourage you to maintain a healthy diet and daily exercise regimen to help you sustain those results! Which option completes the sentence while maintaining the style?

Answer: commendable

Explanation: "Commendable" is the most appropriate word choice for a letter to a patient because it conveys a sense of praise and approval for the improved cholesterol test results. It is a formal and respectful term that acknowledges the patient's efforts and achievements in maintaining their health.

A sample containing helium gas at 0.20 atm compresses so that its volume is halved at a constant temperature. What is the new pressure in atmospheres?

Answer: 0.40

Explanation: When a gas is compressed at a constant temperature, its pressure increases inversely to the volume. So, if the volume is halved, the pressure doubles. In this case, if the initial pressure is 0.20 atm and the volume is halved, the new pressure becomes 0.40 atm, as the pressure doubles when the volume is halved.