during embryonic development most vertebrates exhibit structures called pharyngeal pouches these pouches eventually develop into different structures

ATI TEAS 7

TEAS 7 science practice

1. During embryonic development, most vertebrates exhibit structures called pharyngeal pouches. These pouches eventually develop into different structures in various vertebrate groups, such as the human jaw and inner ear. Pharyngeal pouches are an example of:

A. Analogous structures with different evolutionary origins but similar functions
B. Homologous structures with a common evolutionary origin but diverse functions
C. Vestigial structures that no longer serve a vital function in some organisms
D. Atavisms, the reappearance of a trait absent in recent generations

Correct answer: B

Rationale: Pharyngeal pouches in vertebrates are an example of homologous structures because they share a common evolutionary origin. Despite developing into different structures in various vertebrate groups, such as the jaw and inner ear in humans, these structures originated from the same ancestral feature. This concept of homology highlights the evolutionary relationship between different species and how structures can be modified over time to serve different functions while retaining a common origin. Choice A is incorrect because analogous structures have similar functions but different evolutionary origins, which does not apply to pharyngeal pouches. Choice C is incorrect as vestigial structures are remnants of features that were functional in ancestors but have reduced or lost their original function, which is not the case for pharyngeal pouches. Choice D is incorrect because atavisms refer to the reappearance of traits absent in recent generations, which is not the characteristic of pharyngeal pouches.

2. Positron emission tomography (PET) scans utilize a key property of positrons for medical imaging. What is this property?

A. High mass
B. Positive charge
C. Extreme stability
D. Identical behavior to electrons

Correct answer: B

Rationale: Positron emission tomography (PET) scans utilize the property of positrons having a positive charge. Positrons are the antimatter counterpart of electrons, having the same mass but opposite charge. When a positron collides with an electron, they annihilate each other, producing gamma rays that can be detected by the PET scanner to create images of the body's internal structures and functions. Choice A is incorrect because positrons have the same mass as electrons. Choice C is incorrect as positrons are not extremely stable due to their tendency to annihilate when they encounter electrons. Choice D is incorrect as positrons exhibit different behavior than electrons due to their opposite charges.

3. Anya was paid by Company X to analyze dwindling honeybee populations in the Southwest. After measuring hive populations over several months, she noticed no patterns in the geographic distributions of the deaths after comparisons with local maps of interest. This supported her hypothesis, so she took samples of the honey and the bees from the hives and performed dozens of dissections to confirm her suspicions. Which of the following is the most likely hypothesis upon which this research was performed?

A. Honeybees are being killed off, and their hives are destroyed by other extremely aggressive species of bees from the South.
B. Honeybees are contracting parasites in large droves.
C. Honeybees are so sensitive to certain pesticides that they die on contact.
D. Honeybees die in larger numbers around cell phone towers.

Correct answer: B

Rationale: The most likely hypothesis based on the information provided is that honeybees are contracting parasites in large droves. Anya observed no geographic patterns in hive deaths and proceeded to analyze honey and bees for further investigation. This suggests that she suspected a widespread issue affecting multiple hives simultaneously, consistent with a scenario where honeybees are being infected by parasites in high numbers, leading to dwindling populations across different locations. The other choices can be eliminated because there is no mention of aggressive species of bees from the South, no evidence pointing to pesticide sensitivity as the cause, and no indication of a correlation with cell phone towers in the information provided.

4. What is the formula to calculate kinetic energy?

A. Kinetic Energy = Mass × Velocity
B. Kinetic Energy = Force × Distance
C. Kinetic Energy = Power × Time
D. Kinetic Energy = Potential Energy ÷ Time

Correct answer: A

Rationale: Kinetic energy is the energy an object possesses due to its motion. The formula to calculate kinetic energy is KE = 0.5 × mass × velocity^2, which can also be written as KE = mass × (velocity)^2. Therefore, the correct formula is Kinetic Energy = Mass × Velocity. Choice B is incorrect because it represents the work formula. Choice C is incorrect as it represents the formula for work done. Choice D is incorrect as it does not accurately represent the formula for calculating kinetic energy.

5. Which of the following lists the structures found beneath the rib in descending order?

A. Nerve → Artery → Vein
B. Vein → Nerve → Artery
C. Vein → Artery → Nerve
D. Artery → Nerve → Vein

Correct answer: C

Rationale: The correct order of structures found beneath the rib in descending order is Vein → Artery → Nerve. This sequence is important to remember for medical procedures like inserting a chest tube to ensure precision and avoid complications. Choice A is incorrect because the nerve is not typically the structure closest to the rib. Choice B is incorrect as the vein is usually closer to the rib than the nerve. Choice D is incorrect as the artery is usually closer to the rib than the nerve.