1. Which vitamin requires the lymphatic system for proper absorption from the intestine?

A. Vitamin A
B. Vitamin C
C. Vitamin D
D. Vitamin B12

Correct answer: D

Rationale: The correct answer is D, Vitamin B12. Vitamin B12 requires the presence of intrinsic factor, a protein produced by the stomach, for absorption in the small intestine. This complex is then absorbed in the ileum with the help of the intrinsic factor. The absorption of Vitamin B12 is a unique process that relies on the function of the lymphatic system to transport it throughout the body. Vitamins A, C, and D are absorbed through other mechanisms and do not require the lymphatic system for proper absorption.

2. The number of protons in the nucleus of an atom determines its:

A. Mass number
B. Atomic number
C. Isotope
D. Valence electron count

Correct answer: B

Rationale: The atomic number (Z) equals the number of protons in the nucleus and uniquely identifies an element. Mass number (A) includes both protons and neutrons, isotopes have different neutron numbers, and valence electrons are involved in bonding, not atomic identity.

3. Which of the following terms refers to the degeneration of nerve tissue?

A. Potentiation
B. Demyelination
C. Reuptake
D. Neurogenesis

Correct answer: B

Rationale: The correct answer is B: 'Demyelination.' Demyelination is the term used to describe the degeneration of the myelin sheath, the protective covering of nerve fibers. This process can lead to impaired nerve signal transmission and potential nerve damage. 'Potentiation' refers to the strengthening of neural connections, 'Reuptake' is the reabsorption of neurotransmitters by the presynaptic neuron, and 'Neurogenesis' is the generation of new nerve cells. In this context, demyelination is the most appropriate term related to nerve tissue degeneration.

4. During vigorous exercise, the respiratory rate increases to:

A. Meet the increased demand for oxygen in working muscles
B. Eliminate excess carbon dioxide more slowly
C. Conserve energy for physical activity
D. Decrease the amount of oxygen delivered to the body

Correct answer: A

Rationale: During vigorous exercise, the respiratory rate increases to meet the increased demand for oxygen in working muscles. When we exercise vigorously, our muscles require more oxygen to produce energy through aerobic metabolism. Increasing the respiratory rate allows more oxygen to be taken in and transported to the muscles via the bloodstream to support this increased demand. Option A is correct because it accurately reflects the physiological response of the respiratory system to vigorous exercise, ensuring that working muscles receive sufficient oxygen for optimal performance.

5. When you push a book across a table, the book experiences an equal and opposite force from the table. Why doesn't the table move as well?

A. The table is much heavier than the book.
B. The force on the book acts in a different direction.
C. The table has a much larger surface area, distributing the force over a wider area
D. All of the above

Correct answer: C

Rationale: While Newton's third law states that for every action, there is an equal and opposite reaction, the unbalanced force acting on each object depends on their respective masses. The larger mass of the table (compared to the book) experiences a smaller acceleration, making its movement almost imperceptible.

6. Microfilaments and microtubules are both components of the cytoskeleton, but they have different functions. Which of these describes microfilaments?

A. Provide structural support and shape
B. Facilitate cell movement and contraction
C. Form the mitotic spindle during cell division
D. Transport materials within the cell

Correct answer: B

Rationale: Microfilaments are composed of actin filaments and are responsible for facilitating cell movement and contraction. They play a crucial role in processes such as muscle contraction, cell division, and cell shape changes. Microfilaments are involved in generating forces for cell motility and maintaining cell shape, making option B, 'Facilitate cell movement and contraction,' the correct choice. The other options are not accurate for microfilaments: A) Structural support and shape are primarily provided by intermediate filaments, C) Mitotic spindle formation is attributed to microtubules, and D) Transport of materials within the cell is usually carried out by microtubules and motor proteins.