Cancer cells and virus-infected body cells can be killed before activation of adaptive immunity by
phagocytosis
natural killer cells
B-lymphocytes
pinocytosis
T-lymphocytes
The Correct Answer is B
A. Phagocytosis: Phagocytes can engulf and destroy pathogens and debris, but they primarily target extracellular pathogens and particles. They do not specifically recognize and kill cancer cells or virus-infected body cells before adaptive immunity is activated.
B. Natural killer cells: Natural killer (NK) cells are part of the innate immune system and can detect and destroy virus-infected or cancerous cells without prior sensitization. They recognize cells with abnormal or missing MHC class I molecules, allowing them to act immediately, before the adaptive immune system is activated.
C. B-lymphocytes: B cells mediate adaptive immunity by producing antibodies after activation. They require antigen recognition and helper T cell signals, so they cannot kill infected or cancerous cells immediately in the absence of adaptive immune activation.
D. Pinocytosis: Pinocytosis is a cellular process of “cell drinking” where extracellular fluid and dissolved substances are taken up. It does not target abnormal or infected cells for destruction and plays no role in killing cancer or virus-infected cells.
E. T-lymphocytes: Cytotoxic T cells can kill virus-infected or cancer cells, but only after activation through antigen presentation by MHC molecules. They require adaptive immune activation, unlike natural killer cells that act immediately.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is A
Explanation
A. Thymus:The thymus is largest and most active during childhood, producing T lymphocytes and establishing adaptive immunity. With age, it gradually atrophies and is replaced by fatty tissue, leading to reduced production of new T cells in older adults.
B. Appendix:The appendix contains lymphoid tissue, but it does not undergo significant atrophy with age. Its lymphoid function persists, albeit reduced, and it remains structurally present throughout life.
C. Spleen:The spleen retains its structure and immune functions throughout life. Although some immune efficiency may decline with age, it does not undergo true atrophy like the thymus.
D. Tonsils:Tonsils may undergo partial shrinkage after adolescence, but this is variable, and they do not exhibit the pronounced age-related atrophy characteristic of the thymus.
E. Lymph nodes:Lymph nodes may decrease slightly in size with aging, but they generally remain functional throughout life and do not atrophy to the same extent as the thymus.
Correct Answer is D
Explanation
A. The two main types are T cells and macrophages:Macrophages are phagocytic cells, not lymphocytes. The main lymphocyte types are T cells and B cells, which have distinct roles in adaptive immunity.
B. T cells are the only form of lymphocyte found in lymphoid tissue:Both T cells and B cells are present in lymphoid tissues. Lymphoid organs support the activation, proliferation, and differentiation of multiple lymphocyte types.
C. T cells are the precursors of B cells:T cells and B cells develop separately from hematopoietic stem cells. T cells do not differentiate into B cells; they have distinct lineages and functions in immunity.
D. B cells produce plasma cells, which secrete antibodies into the blood:B cells differentiate into plasma cells upon activation. Plasma cells are specialized for antibody production, releasing large amounts of antigen-specific antibodies into the circulation, making this statement correct.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.