Baby Li Is Participating in a Research Study in Which

question 36

Multiple Choice

Baby Li is participating in a research study in which his physical growth is measured once a day. Li's parents were surprised to find out that monthly measurements of height showed gradual increases, but daily measurements revealed growth spurts that sometimes lasted up to 24 hours. This example supports the assertion that physical growth is:

• A) primarily characterized by continuity.
• B) primarily characterized by discontinuity.
• C) both continuous and discontinuous.
• D) characterized neither by continuity nor discontinuity.

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Definitions:

Targeted Areas

Specific geographic or thematic areas identified for focused intervention or study.

Hormones

Chemical messengers produced by the endocrine glands that travel through the bloodstream to target organs or tissues, influencing various bodily functions.

Humoral Immunity

One of the three general categories of immune response, in which invading antigens are presented by macrophages to B-lymphocytes. (“B” stands for bursa, an organ in which such cells are produced in birds. B-lymphocytes derive from the liver and bone marrow in humans.) This causes the B-cells to reproduce—a process reinforced by the lymphokine secretion from the helper T-cells. Some of the activated B-cells remain as memory B-cells. Others go on to be plasma cells, secreting antibodies called immunoglobulins that neutralize antigens in a number of different ways, such as clumping, presenting the antigen to phagocytic cells, or rupturing the antigen.