What is the term for the body's ability to defend itself against specific invading agents such as bacteria, toxins, viruses, and foreign bodies?

Correct Answer: C

Rationale: The correct choice is **C: Immunity**, because it directly refers to the body's complex defense mechanism that recognizes and combats specific pathogens like bacteria, viruses, toxins, and foreign bodies. Immunity involves both innate (general defenses like skin and phagocytes) and adaptive (specific responses like antibodies and memory cells) systems, which work together to identify, neutralize, and remember threats for faster future responses. This term encompasses the precise biological processes (e.g., antigen recognition, lymphocyte activation) that target invaders, making it the only option that fully aligns with the question’s focus on *specific* defense. **A: Hormones** is incorrect because hormones are chemical messengers (e.g., insulin, adrenaline) that regulate physiological functions like metabolism and growth, not pathogen defense. While some hormones may *influence* immune responses indirectly (e.g., cortisol suppressing inflammation), they do not constitute the body’s targeted defense system. Hormones lack the specificity to identify and remember pathogens, a hallmark of immunity. **B: Secretion** is incorrect because it broadly refers to the release of substances (e.g., enzymes, mucus) by glands or cells. Although secretions like stomach acid or mucus *contribute* to nonspecific defenses, they are not a coordinated system for targeting *specific* invaders. Secretions lack the adaptive precision of immune responses, such as antibody production tailored to a particular virus. **D: Glands** is incorrect because glands are organs that produce and release substances (e.g., sweat, saliva). While some glandular secretions (e.g., lysozyme in tears) have antimicrobial properties, glands themselves are not a defense mechanism. The question asks about the *ability* to defend, which involves systemic processes (e.g., immune cell activation), not anatomical structures. Glands play a supportive role but do not orchestrate pathogen-specific responses. Immunity stands out as the correct answer because it encapsulates the dynamic, targeted biological strategies (e.g., memory B cells, cytotoxic T cells) that distinguish it from broader physiological processes or structures. The incorrect choices either lack specificity (secretion, glands) or address unrelated regulatory functions (hormones). Understanding immunity requires recognizing its dual innate/adaptive components and its role in maintaining homeostasis against pathogens, which the other options cannot fulfill.

Correct Answer: A

Rationale: The lens is the correct answer because it is the transparent, biconvex structure in the eye responsible for focusing light onto the retina. It adjusts its shape through a process called accommodation, controlled by the ciliary muscles, to fine-tune the focus for near or distant objects. The lens works in conjunction with the cornea to refract incoming light, ensuring a clear image is projected onto the retina. Its transparency and flexibility are crucial for proper vision, and any opacity (cataracts) or rigidity (presbyopia) can impair this function. The cornea (Choice C) is incorrect because, although it is also transparent and contributes to light refraction (accounting for about two-thirds of the eye’s focusing power), it does not adjust its shape to focus light dynamically. The cornea’s primary role is to protect the eye and provide a fixed refractive surface, not to fine-tune focus like the lens does. The sclera (Choice B) is incorrect because it is the white, opaque outer layer of the eye that provides structural support and protection. It has no role in focusing light—its rigidity and lack of transparency make it incapable of contributing to the optical pathway. The pupils (Choice D) are incorrect because they are merely openings in the iris that regulate the amount of light entering the eye by dilating or constricting. While they influence light exposure, they do not refract or focus light—that function belongs to the cornea and lens. The pupils act like a camera aperture, adjusting brightness rather than sharpening the image. Thus, the lens is the only structure among the choices that dynamically focuses light onto the retina, making it the correct answer. The cornea aids in refraction but does not adjust, while the sclera and pupils perform entirely different functions unrelated to focusing light. Understanding these distinctions is essential for grasping how the eye processes visual information.

Correct Answer: A

Rationale: Orem's theory, also known as the Self-Care Deficit Nursing Theory, emphasizes individuals' ability to perform self-care to maintain health and well-being. One aspect of this theory is the maintenance of a sufficient intake of air, which is essential for sustaining life and overall health. This self-care component focuses on the individual's ability to meet their physiological needs, including the intake of air, to promote optimal functioning and health.

Correct Answer: D

Rationale: Maslow's hierarchy of needs is a theory in psychology that categorizes human needs into five levels. These levels, from the most fundamental to the highest, are physiological needs, safety needs, love and belongingness, esteem needs, and self-actualization. Therefore, all the clusters listed in the choices - love and belonging, physiological needs, and self-actualization - correspond to different levels within Maslow's hierarchy of needs. Choosing 'All of the above' (option D) is the correct answer as it includes all the clusters associated with Maslow's theory.

Correct Answer: B

Rationale: Acute illnesses are characterized by the sudden onset of severe symptoms that typically last for a short duration. These conditions usually resolve within a defined period, unlike chronic illnesses that persist over a longer time frame. Pain and syndrome are not specific types of illnesses but rather symptoms or clinical manifestations that can occur in various health conditions.