Adaptive immunity

Antibodies are classified by size, location, and function, and which one of the following represents the most common type of immunoglobulin?

• A) IgM

• B) IgG

• C) IgA

• D) IgD

• E) MHC

The advantage of having memory cells in specific defenses is that

• A) they remain in an active state, continuously producing antibodies

• B) if exposed to an antigen a second time, they quickly become plasma cells

• C) they prevent production of other proteins so that antibodies can be produced

• D) they produce antibodies and can become phagocytic

• E) they prevent viruses from entering the body a second time

Which one of the following types of T cells is a critical component of the immune system because it stimulates and enhances the activity of other components of the immune system?

• A) T suppressor cell

• B) T memory cell

• C) T helper cell

• D) cytotoxic T cell

• E) natural killer cells

Which one of the following is correct regarding the structure of an antibody?

• A) An antibody is made up of two polypeptide chains linked by hydrogen bonds.

• B) The four polypeptide chains that make up an antibody molecule are linked by disulfide bonds.

• C) The constant regions of the polypeptides in an antibody form antigen-binding sites.

• D) Only one polypeptide in an antibody has a constant region and a variable region.

• E) The polypeptides making up an antibody are connected by hydrogen bonds.

Clonal selection implies that

• A) brothers and sisters have similar immune responses.

• B) antigens increase mitosis in specific lymphocytes.

• C) only certain cells can produce interferon.

• D) a B cell has multiple types of antigen receptors.

• E) the body selects which antigens it will respond to.

For one person to produce over a million different antibody molecules could not possibly require over a million different genes. Instead, this variability is accounted for by which processes?

• A) alternative splicing of exons after transcription

• B) increased rate of mutation in the RNA molecules

• C) DNA rearrangements followed by alternative splicing of the transcripts

• D) DNA rearrangements in the thymus cells

• E) crossing-over between the light and heavy chains of each antibody molecule during meiosis I

Which one of the following best explains why people get so many colds in their lifetime?

• A) The immune system has a hard time identifying the viruses that cause the colds.

• B) The viruses that cause these colds constantly produce new antibodies, which cause the symptoms.

• C) These individuals do not produce enough white blood cells.

• D) The viruses that cause colds evolve rapidly, which results in a change in their antigenic structure.

• E) The B cells of these individuals destroy their T cells.

Which one type of cells are responsible for producing and releasing antibodies?

• A) red bone marrow

• B) B lymphocytes

• C) T lymphocytes

• D) macrophages

• E) natural killer cells

Clonal selection is an explanation for how

• A) a single type of stem cell can produce both red blood cells and white blood cells.

• B) V, J, and C gene segments are rearranged.

• C) an antigen can provoke production of high levels of specific antibodies.

• D) HIV can disrupt the immune system.

• E) macrophages can recognize specific T cells and B cells.