Which of the following statements best explains why young children develop infections more often than older children and adolescents?
A)Cell-mediated immunity doesn't achieve full function until a child is roughly 5 years old.
B)The thymus doesn't begin to function until adolescence, so prior to this time, children don't produce enough T cells to adequately protect them from infectious agents.
C)Children don't develop all of the immunoglobulins they need to protect against infection until they are about 6 or 7 years of age.
D)Young children have comparatively small lymphoid tissues, which means they are less able to fight infection than are older children.

Question

Quizplus · Accepted Answer

A)Children do not develop adequate levels of certain immunoglobulins (namely, IgA, IgE, and IgG)until they are 6 or 7 years old, so prior to this time, they are at increased risk of infection. Note, however, that cell-mediated immunity achieves full function early in life. This occurs in part because the thymus begins producing T cells during the fetal period, and also because young children have lymphoid tissues that are quite large in comparison to the rest of their bodies.
B)Children do not develop adequate levels of certain immunoglobulins (namely, IgA, IgE, and IgG)until they are 6 or 7 years old, so prior to this time, they are at increased risk of infection. Note, however, that cell-mediated immunity achieves full function early in life. This occurs in part because the thymus begins producing T cells during the fetal period, and also because young children have lymphoid tissues that are quite large in comparison to the rest of their bodies.
C)Children do not develop adequate levels of certain immunoglobulins (namely, IgA, IgE, and IgG)until they are 6 or 7 years old, so prior to this time, they are at increased risk of infection. Note, however, that cell-mediated immunity achieves full function early in life. This occurs in part because the thymus begins producing T cells during the fetal period, and also because young children have lymphoid tissues that are quite large in comparison to the rest of their bodies.
D)Children do not develop adequate levels of certain immunoglobulins (namely, IgA, IgE, and IgG)until they are 6 or 7 years old, so prior to this time, they are at increased risk of infection. Note, however, that cell-mediated immunity achieves full function early in life. This occurs in part because the thymus begins producing T cells during the fetal period, and also because young children have lymphoid tissues that are quite large in comparison to the rest of their bodies.

Which of the Following Statements Best Explains Why Young Children