1. Which hormone, produced by the thyroid gland, plays a key role in regulating calcium levels in the blood by promoting calcium release from bones and increasing calcium reabsorption in the kidneys?

A. Calcitonin
B. Parathyroid hormone (PTH)
C. Thyroxine
D. Insulin

Correct answer: b

Rationale: The correct answer is B: Parathyroid hormone (PTH). PTH is produced by the parathyroid glands, not the thyroid gland. PTH plays a crucial role in regulating calcium levels in the blood by promoting calcium release from bones and increasing calcium reabsorption in the kidneys. This hormone acts in opposition to calcitonin, which is produced by the thyroid gland and works to lower blood calcium levels by promoting calcium deposition into bones. Thyroxine (C) is a thyroid hormone that regulates metabolism, not calcium levels. Insulin (D) is a hormone produced by the pancreas that regulates blood sugar levels, not calcium levels.

2. What is the CRISPR-Cas9 system used for in gene editing?

A. To amplify specific DNA sequences.
B. To cut DNA at specific locations.
C. To deliver genes into cells.
D. To sequence entire genomes.

Correct answer: B

Rationale: Rationale: The CRISPR-Cas9 system is a powerful tool used in gene editing to precisely target and cut DNA at specific locations within the genome. This system consists of a guide RNA that directs the Cas9 enzyme to the desired DNA sequence, where it creates a double-strand break. This break can then be repaired by the cell's natural DNA repair mechanisms, allowing for the introduction of specific genetic modifications. Options A, C, and D do not accurately describe the primary function of the CRISPR-Cas9 system in gene editing.

3. In a horizontal chart, the lowest level worker is located at the

A. Leftmost box
B. Middle
C. Rightmost box
D. Bottom

Correct answer: B

Rationale: In a horizontal chart, the lowest level worker is typically positioned at the leftmost side, with higher-level workers placed to the right. This arrangement signifies hierarchy, with the top level usually being on the rightmost side. Therefore, the correct answer is B: 'Middle,' as the lowest level worker is situated towards the left of the chart, not the extreme left or right. This positioning helps visually represent the organization's structure and indicates the progression from lower to higher levels as one moves from left to right on the chart.

4. What type of waves require a medium (solid, liquid, or gas) to propagate?

A. Transverse waves
B. Longitudinal waves
C. Electromagnetic waves
D. Surface waves

Correct answer: B

Rationale: Longitudinal waves require a medium (solid, liquid, or gas) to propagate because the particles in the medium move parallel to the direction of the wave. Transverse waves, on the other hand, do not require a medium and can propagate through a vacuum. Electromagnetic waves also do not require a medium for propagation, as they consist of oscillating electric and magnetic fields. Surface waves are a combination of both longitudinal and transverse waves and also require a medium to propagate.

5. Deficiency in which vitamin can lead to a condition called pernicious anemia, affecting vitamin B12 absorption in the digestive system?

A. Vitamin A
B. Vitamin B12 (cobalamin)
C. Vitamin D
D. Vitamin E

Correct answer: B

Rationale: The correct answer is B: Vitamin B12 (cobalamin). Pernicious anemia is a condition caused by a deficiency in vitamin B12, which is essential for the production of red blood cells and for the proper functioning of the nervous system. This vitamin is primarily absorbed in the digestive system, particularly in the ileum of the small intestine. In pernicious anemia, there is a lack of intrinsic factor, a protein produced by the stomach, which is necessary for the absorption of vitamin B12. Deficiencies in other vitamins like Vitamin A, Vitamin D, or Vitamin E do not directly lead to pernicious anemia. Therefore, the correct answer is Vitamin B12.

6. Ms. Castro learns that some leaders are transactional leaders. Which of the following does

A. Focuses on management tasks
B. Is a caretaker
C. Uses trade-offs to meet goals
D. Inspires others with vision

Correct answer: C

Rationale: The correct answer is C: 'Uses trade-offs to meet goals.' Transactional leaders focus on the exchange or transaction that occurs between them and their followers. They set clear expectations and goals for their followers and use rewards and punishments to motivate them. This approach involves making trade-offs to achieve desired outcomes, such as rewarding employees for meeting targets or penalizing them for not meeting expectations. Options A and B do not directly relate to transactional leadership, as it is more about goal achievement and motivation through rewards and punishments. Option D describes a transformational leader, who inspires and motivates others through a shared vision and values, which is different from the transactional leadership style described in the question.