memory b cells and memory t cells are crucial for immunological memory how does immunological memory enhance the immune response upon re exposure to a

ATI TEAS 7

TEAS version 7 quizlet science

1. Memory B cells and memory T cells are crucial for immunological memory. How does immunological memory enhance the immune response upon re-exposure to a pathogen?

A. It increases the production of the same ineffective antibodies.
B. It allows for a quicker and more robust immune response.
C. It suppresses the immune system to prevent overreaction.
D. It triggers a completely different immune response.

Correct answer: B

Rationale: Immunological memory enhances the immune response upon re-exposure to a pathogen by allowing for a quicker and more robust immune response. Memory B cells and memory T cells are primed to recognize the pathogen quickly and mount a faster and more effective response, leading to a more efficient clearance of the pathogen. Choice A is incorrect because immunological memory does not increase the production of ineffective antibodies but rather promotes the production of specific antibodies that are effective against the pathogen. Choice C is incorrect as immunological memory does not suppress the immune system; instead, it enhances the response. Choice D is incorrect because immunological memory leads to a recall of the specific immune response mounted during the initial exposure, not a completely different response.

2. Which plane divides the body into left and right halves?

A. Sagittal/Median Plane
B. Frontal/Coronal Plane
C. Transverse/Cross-Section Plane
D. Horizontal Plane

Correct answer: A

Rationale: The correct answer is A: Sagittal/Median Plane. This plane divides the body into left and right halves. The Frontal/Coronal Plane (choice B) divides the body into front and back, while the Transverse/Cross-Section Plane (choice C) divides it into top and bottom. The Horizontal Plane (choice D) divides the body into upper and lower portions. Understanding these planes is essential in anatomy as they help describe the orientation and relationships of body structures.

3. Which statement most accurately compares and contrasts the structures of DNA and RNA?

A. Both DNA and RNA have 4 nucleotide bases. Three of the bases are the same, but the fourth base is thymine in DNA and uracil in RNA.
B. Both DNA and RNA have the same 4 nucleotide bases. However, the nucleotides bond differently in DNA compared to RNA.
C. Both DNA and RNA have different numbers of nucleotide bases. DNA is a double helix while RNA is a single strand.
D. Both DNA and RNA have a double helix structure. However, DNA contains 6 nucleotide bases and RNA contains 4 nucleotide bases.

Correct answer: A

Rationale: The correct answer is A because DNA and RNA both consist of 4 nucleotide bases, namely adenine, cytosine, and guanine, which are common in both. The key difference lies in the fourth base, which is thymine in DNA and uracil in RNA. This distinction is fundamental in understanding the structural variances between DNA and RNA. Choice B is incorrect as it incorrectly states that the nucleotides bond differently in DNA compared to RNA without specifying the crucial base differences. Choice C is inaccurate as it misrepresents the numbers of nucleotide bases in DNA and RNA, and incorrectly describes DNA as a double helix and RNA as a single strand, which is not related to the difference in bases. Choice D is incorrect as it inaccurately portrays DNA with 6 nucleotide bases and RNA with 4, which is not true; both DNA and RNA have 4 nucleotide bases, but with differences in one of the bases.

4. What is the primary function of the atrioventricular (AV) node within the heart?

A. Generate the electrical impulse for contraction (pacemaker function)
B. Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction.
C. Increase blood pressure within the ventricles during systole.
D. Separate oxygenated and deoxygenated blood flow in the heart.

Correct answer: B

Rationale: The correct answer is B: Transmit the electrical impulse from the atria to the ventricles, regulating the timing of contraction. The primary function of the atrioventricular (AV) node is to coordinate the transmission of electrical signals between the atria and the ventricles. It ensures proper timing between atrial and ventricular contractions, allowing for efficient blood pumping through the heart. Choice A is incorrect because the AV node does not generate the initial electrical impulse; that role is typically attributed to the sinoatrial (SA) node. Choice C is incorrect as the AV node does not directly influence blood pressure within the ventricles. Choice D is also incorrect as the separation of oxygenated and deoxygenated blood is primarily achieved by the anatomical structure of the heart (e.g., atria and ventricles) and not the AV node.

5. The acceleration of a falling object due to gravity has been proven to be 9.8 m/s^2. A scientist drops a cactus four times and measures the acceleration with an accelerometer and gets the following results: 9.79 m/s^2, 9.81 m/s^2, 9.80 m/s^2, and 9.78 m/s^2. Which of the following accurately describes the measurements?

A. They're both accurate and precise.
B. They're accurate but not precise.
C. They're precise but not accurate.
D. They're neither accurate nor precise.

Correct answer: A

Rationale: The measurements are close to the true value of 9.8 m/s^2 and are also close to each other, indicating both accuracy and precision. Accuracy refers to how close a measurement is to the true value, while precision refers to how close repeated measurements are to each other. In this case, the measurements are accurate because they are close to the accepted value of 9.8 m/s^2, and they are precise because they are clustered closely around each other. Therefore, choice A, 'They're both accurate and precise,' is the correct answer. Choice B is incorrect because the measurements are precise as they are close to each other, but they are also accurate as they are close to the true value. Choice C is incorrect because the measurements are accurate as they are close to the true value, and choice D is incorrect because the measurements exhibit both accuracy and precision in this scenario.