Macrophages differentiate

Correct Answer: B

Rationale: Macrophages differentiate in tissues because they originate from monocytes which leave the bloodstream and mature into macrophages in various tissues. This process is essential for their diverse functions in immune response and tissue maintenance. Choices A, C, and D are incorrect because macrophages do not differentiate from blood neutrophils, the common lymphoid progenitor, or in the bone marrow.

Correct Answer: D

Rationale: The correct answer is D because auxin hormones play a crucial role in promoting seedling elongation (A), are transported downward through a plant (B), and affect cell elongation in roots at lower concentrations (C). Auxins are known for their ability to stimulate cell growth and elongation, which is essential for seedling growth. They are also transported in a polar manner from the shoot tip downwards, influencing various plant processes along the way. Additionally, auxins regulate root growth by promoting cell elongation at lower concentrations. Therefore, all the statements (A, B, and C) are supported by the functions of auxin hormones, making option D the correct choice.

Correct Answer: B

Rationale: The correct answer is B: to vaccination. Acquired immunity is the immune response developed after exposure to a vaccine, which stimulates the immune system to recognize and remember specific pathogens. Vaccination helps the body build immunity without causing serious illness like choice A, without requiring repeated exposure like choice C, and without being related to treatment with penicillin like choice D. Vaccination mimics natural infection, prompting the body to produce memory cells that can respond more effectively when encountering the actual pathogen in the future.

Correct Answer: A

Rationale: The correct answer is A: Leukocytosis. Leukocytosis refers to an abnormal increase in white blood cells, indicating an immune response. Thrombocytosis (B) is an increase in platelets, not white blood cells. Anemia (C) is a decrease in red blood cells. Hemolysis (D) is the breakdown of red blood cells, not related to an increase in white blood cells. Therefore, A is the correct answer as it specifically relates to an abnormal increase in white blood cells.

Correct Answer: D

Rationale: Rationale: Robert Koch is correctly paired with developing techniques to grow pure bacterial cultures. Koch's work laid the foundation for bacteriology and allowed for the isolation and identification of specific disease-causing bacteria. This technique, known as Koch's postulates, revolutionized the field of microbiology by linking specific pathogens to specific diseases. Summary: A: Louis Pasteur - Incorrect. While Pasteur is known for his work in vaccination and pasteurization, the provided accomplishment is associated with Edward Jenner, not Pasteur. B: Paul Ehrlich - Incorrect. Ehrlich is known for his work on immunology and coined the term "magic bullet," but he did not identify lymphocytes as cells mediating adaptive immunity. C: MacFarlane Burnet - Incorrect. Burnet is known for his clonal selection theory, not the side-chain theory of antibodies as described in the choice.