Question

partner practice regents problems:

1. the immune system of humans may respond to chemicals on the surface of an invading organism by

(1) releasing hormones that break down these chemicals
(2) synthesizing antibodies that mark these organisms to be destroyed
(3) secreting antibiotics that attach to these organisms
(4) altering a dna sequence in these organisms

Explanation:

• Hormones are related to the endocrine system, not the immune system, so option (1) is incorrect.
• Antibiotics are produced by some microorganisms and are used externally (like in medicine), not secreted by the human immune system to directly attach to invading organisms, so option (3) is incorrect.
• The human immune system does not alter the DNA sequence of invading organisms, so option (4) is incorrect.
• When the immune system recognizes chemicals (antigens) on the surface of an invading organism (like a pathogen), it can synthesize antibodies. These antibodies mark the organisms (pathogens) so that other cells of the immune system can destroy them.

Answer:

(2) synthesizing antibodies that mark these organisms to be destroyed