________ lacks the capacity to remember a pathogen or react differently to it in the future, whereas ________ utilizes memory cells to adapt to a given pathogen and ward it off more easily in the future.

Choice A rationale

Hemopoiesis is the general term for blood cell formation. Myeloid hemopoiesis refers to the formation of red blood cells, granulocytes, monocytes, and platelets, which primarily occurs in the red bone marrow. Lymphoid hemopoiesis refers to the formation of lymphocytes, which occurs in lymphatic organs such as the lymph nodes, thymus, and spleen, but also significantly in the bone marrow for B-cell maturation and T-cell precursors. The statement incorrectly implies that lymphoid hemopoiesis occurs *only* in lymphatic organs and myeloid *only* in bone marrow, and the phrasing reverses their typical associations.

Choice B rationale

The statement is false. Hemopoiesis is indeed the formation of blood cells. Myeloid hemopoiesis, the formation of most blood cell types (erythrocytes, granulocytes, monocytes, platelets), predominantly occurs in the red bone marrow. Lymphoid hemopoiesis, the formation of lymphocytes, occurs in lymphoid tissues (lymph nodes, thymus, spleen) but also originates from stem cells in the bone marrow, with B cells maturing there and T cell precursors migrating to the thymus. The original statement incorrectly defines the primary sites and the relationship between lymphoid and myeloid hemopoiesis.

Choice C rationale

The statement contains fundamental inaccuracies regarding the primary sites of lymphoid and myeloid hemopoiesis. While there are overlaps and precursor origins in bone marrow for both lineages, the generalized and exclusive assignments made in the statement are incorrect, making it fully false rather than partially true.

Choice D rationale

The processes of lymphoid and myeloid hemopoiesis and their respective sites of formation are well-established scientific facts. There is no ambiguity or lack of information to render the statement "undetermined.”. The current understanding of hematopoiesis clearly refutes the claim. .

Choice D rationale

Hyposecretion, or inadequate hormone release, can indeed result from a combination of factors. Tumors or lesions directly destroying glandular tissue (primary hyposecretion), interference with the gland's ability to receive stimulating signals (secondary hyposecretion), or inadequate trophic hormone stimulation from a higher center all lead to insufficient hormone production.

Choice A rationale

Tumors or lesions that destroy an endocrine gland directly impair its ability to synthesize and secrete hormones, leading to primary hyposecretion. For example, damage to pancreatic islet cells can cause insufficient insulin production, leading to diabetes mellitus.

Choice B rationale

Tumors or lesions that interfere with a gland's ability to receive signals from another gland, such as the pituitary, result in secondary hyposecretion. If the adrenal cortex cannot respond to ACTH due to receptor damage, it will not produce sufficient corticosteroids.

Choice C rationale

Inadequate stimulation of the gland, such as insufficient release of a trophic hormone from the pituitary or hypothalamus, leads to insufficient hormone production. For example, if the pituitary does not release enough TSH, the thyroid gland will exhibit hyposecretion of thyroid hormones.