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. How does an increase in mass affect the force required to produce the same acceleration on an object?

A. Increases force required
B. Decreases force required
C. Has no effect on force required
D. Causes unpredictable changes in force required

Correct answer: A

Rationale: The correct answer is A, 'Increases force required.' According to Newton's second law of motion, force is directly proportional to mass and acceleration (F = ma). Therefore, an increase in mass will require an increase in force to produce the same acceleration on an object. Choice B is incorrect because an increase in mass does not decrease the force required; it increases it. Choice C is incorrect as increasing mass does affect the force required. Choice D is incorrect as the relationship between mass and force is predictable according to Newton's laws of motion.

3. Which chamber of the heart is the largest?

A. Right atrium
B. Left atrium
C. Right ventricle
D. Left ventricle

Correct answer: D

Rationale: The correct answer is D, the left ventricle. The left ventricle is the largest and strongest chamber of the heart. It is responsible for pumping oxygenated blood to the entire body through the aorta, playing a crucial role in the circulatory system. Choices A, B, and C are incorrect. The right atrium receives deoxygenated blood from the body, the left atrium receives oxygenated blood from the lungs, and the right ventricle pumps deoxygenated blood to the lungs for oxygenation. However, the left ventricle is the largest chamber and performs the vital function of pumping oxygen-rich blood to the body.

4. During exercise, heart rate increases to deliver more oxygen to the body's tissues. What other cardiovascular response also increases?

A. Blood pressure decreases
B. Blood vessel diameter narrows
C. Blood flow to muscles increases
D. Blood viscosity thickens

Correct answer: C

Rationale: During exercise, the cardiovascular response includes an increase in blood flow to the muscles to deliver more oxygen and nutrients needed for energy production. This helps to support the increased demand for oxygen and nutrients by the working muscles. Blood pressure typically increases during exercise to help facilitate this increased blood flow to the muscles. Additionally, blood vessel diameter may widen (vasodilation) to allow for more blood flow, rather than narrow. Blood viscosity does not typically thicken during exercise.

5. What happens when a protein unfolds?

A. Activation
B. Denaturation
C. Renaturation
D. Folding

Correct answer: B

Rationale: - Activation (Option A) refers to the process of initiating or increasing the activity of a molecule, such as an enzyme. Protein unfolding does not involve activation. - Denaturation (Option B) is the correct answer. Denaturation refers to the process by which a protein loses its three-dimensional structure, leading to the disruption of its function. This can be caused by factors such as heat, pH changes, or chemicals. - Renaturation (Option C) is the process by which a denatured protein regains its native structure and function. Protein unfolding is the opposite of renaturation. - Folding (Option D) is the process by which a protein assumes its functional three-dimensional structure. Unfolding is the reverse process of folding, not folding itself.