Mixed Deck — All MCAT Topics Flashcards

In Merton's strain theory, an individual who rejects both the cultural goals of society and the legitimate means to achieve them, then substitutes new goals and means, is classified as a:

Answer: Rebel

Rebels reject society's goals and means and actively seek to replace them with alternative ones, as seen in revolutionary social movements.

Which step of fatty acid synthesis requires the direct input of CO₂ (as bicarbonate)?

Answer: Carboxylation of acetyl-CoA to malonyl-CoA

Acetyl-CoA carboxylase adds CO₂ to acetyl-CoA to form malonyl-CoA, the activated two-carbon donor for fatty acid chain elongation.

Which memory category would explicit memory fall into?

Answer: long-term memory

Explicit memory, also known as declarative memory, refers to memories that are consciously recalled, such as facts, events, and concepts. This type of memory is a component of long-term memory, which has a vast capacity and can store information for extended periods, ranging from minutes to a lifetime.

An individual comes to the clinic for an initial evaluation and to begin treatment. The patient was born as a 46-year-old man named XY, but she identifies as a woman. She/Her are her preferred pronouns. Furthermore, she is only sexually active with females. What would you use to characterize this person's gender and sexual orientation?

Answer: Transgender, homosexual

Answer Explanation: (B) Gender discussions are becoming increasingly important in the field of medicine as of late. In order to appropriately address this, these definitions have become more important. Gender is spoken of in relation to what biological sex the infant has, whereas sexual orientation is described in relation to the individual’s identified gender.

Which protein secondary structure is stabilized by hydrogen bonds between residues distant in primary sequence?

Answer: Beta sheet

Beta sheets form hydrogen bonds between backbone atoms of strands that are far apart in the primary sequence, while alpha helices bond residues close together (i and i+4).

Which scientific method step follows hypothesis formation?

Answer: Experimentation and testing

After forming a hypothesis, the next step is designing and conducting experiments to test whether the hypothesis is supported by evidence.

During eukaryotic RNA processing, which modification is added to the 5' end of pre-mRNA?

Answer: A 7-methylguanosine (m7G) cap

A 7-methylguanosine cap is co-transcriptionally added to the 5' end of pre-mRNA, protecting it from exonucleolytic degradation and facilitating ribosome recognition for translation initiation.

Which nerve innervates the diaphragm?

Answer: Phrenic nerve (C3-C5)

The phrenic nerve, arising from cervical spinal levels C3-C5, provides motor innervation to the diaphragm.

Which protecting group strategy would allow selective acylation of an amine in the presence of an alcohol?

Answer: Protect the alcohol as a TBS ether, then acylate the free amine

Converting the alcohol to a silyl ether (TBS) blocks the OH from reacting, leaving the amine free for selective acylation under mild conditions.

A CARS passage on evolutionary biology states: 'Altruistic behavior in animals poses a challenge to naive interpretations of natural selection.' The word 'naive' as used here most nearly means:

Answer: Oversimplified and failing to account for complexity

In academic prose, 'naive' applied to a theory means it oversimplifies and fails to capture the phenomenon's full complexity.

According to some researchers, the US federal government did less to safeguard residents whose homes were taken away in false foreclosures during the 2007–2008 financial crisis than to defend the banks that engaged in this illegal action. What effect does this have on the passage if it's true?

Answer: It supports the author's central argument.

The author's central argument, especially in the final paragraph, is that the federal government has become a 'bureaucratic behemoth, ultimately in thrall to the nouveau aristocracy of corporate 'persons' and the rapacious class of executives.' The hypothetical scenario, where the government protects banks over citizens in foreclosures, directly supports this claim that the government prioritizes powerful corporate interests over the well-being of the general populace, thus strengthening the author's main thesis.

Which of the following responses, based on this graph, would increase the reaction's velocity the fastest? The Michaelis-Menten Equation defines the speed of a reaction in terms of substrate amount and enzyme affinity for that substrate. It's frequently depicted in the same way as the graph below:

Answer: Increasing the amount of substrate from a starting point below Km

The Michaelis-Menten graph shows that at very low substrate concentrations (well below Km), the reaction velocity is directly proportional to the substrate concentration. This is because there are many free enzyme active sites available to bind substrate. Therefore, increasing the substrate from a point below Km will lead to the fastest initial increase in reaction velocity as more enzyme active sites become occupied.

Two point charges of +2 μC and +8 μC are 12 cm apart. At what distance from the +2 μC charge does the electric field equal zero?

Answer: 4 cm

Setting kQ₁/r² = kQ₂/(d–r)²: 2/r² = 8/(12–r)²; solving gives r = 4 cm from the +2 μC charge.

A researcher studying attachment finds that infants who explore freely when their caregiver is present but become distressed when left alone and are easily soothed upon reunion are classified as which attachment type?

Answer: Secure attachment

Secure attachment is characterized by using the caregiver as a safe base for exploration, distress upon separation, and quick comfort upon reunion.

Which of the following best describes the Doppler effect when a sound source moves toward a stationary observer?

Answer: Observed frequency is higher than emitted frequency

When a source moves toward an observer, sound wavefronts bunch together, shortening wavelength and increasing observed frequency.

A passage attributes the decline of print journalism primarily to the internet's disruption of advertising revenue. A critic argues that declining readership preceded internet adoption. This critique:

Answer: Challenges the author's timeline, suggesting the cause may precede the proposed cause

If readership fell before the internet became widespread, the internet cannot be the primary cause of print journalism's decline, undermining the author's causal sequence.

A researcher finds that individuals from lower socioeconomic backgrounds have poorer health outcomes even when controlling for access to healthcare. This best illustrates the concept of:

Answer: Fundamental cause theory

Fundamental cause theory posits that socioeconomic status is a root cause of health disparities because it determines access to resources that protect health across many risk factors.

Which of the following compounds can pass through the descending loop of Henle of the nephron of the kidney?

Answer: H2O

The descending loop of Henle is highly permeable to water but relatively impermeable to solutes like Na+, Cl-, and K+. As the filtrate moves down this segment, water passively exits the tubule into the hypertonic medullary interstitium, concentrating the filtrate. This selective permeability is crucial for the kidney's ability to concentrate urine.

A scientist conducting research on hearing aids fitted 30 mice with the newest technology after they were genetically changed to lose their hearing and were tested to press a lever when they heard a bell. This was set to a range of power levels. Twenty mice pressed the lever at 80% power. 15 mice pressed the lever at 70 percent power. Ten mice pressed the lever with 60 percent power. Which of the following is the absolute threshold for hearing the decibels produced by the bell?

Answer: 70%

Answer Explanation: (B) This question rests exclusively on the knowledge of what defines the absolute threshold of sensation, which is when 50% of the time, the stimulus is recorded. In this question, with the information given, that would mean the power setting that would allow 15 mice to observe the sound of the bell. Below this would be subliminal.

A sociologist observes that people in higher socioeconomic classes have better access to healthcare, education, and nutrition. This pattern is best explained by which concept?

Answer: Social stratification

Social stratification refers to the hierarchical ranking of individuals or groups in society based on wealth, power, and prestige, leading to differential access to resources.