Biology

Human Immunity and Blood

2,051 Questions

Human immunity and blood questions cover the physiological mechanisms protecting the body against diseases and the components of blood. Topics include blood groups, cell mediated immunity, monoclonal antibodies, and blood coagulation. These biology topics frequently appear in general science sections of competitive exams.

Blood groupsCell mediated immunityMonoclonal antibodiesBlood coagulationCancer immunology

Human Immunity and Blood Questions

Multiple choice

Where are B lymphocytes located?

  1. Efferent lymph

  2. Blood and lymphoid tissue

  3. Blood

  4. Lymph nodes

  5. Reticuloendothelial cells
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

B lymphocytes are located here.

Multiple choice

Specific immunity to M. tuberculosis in mice, can be transferred to naive histocompatible recipients by which of the following?

  1. B-cells

  2. T-cells

  3. Macrophages

  4. Neutrophils

  5. IgG
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

T-cells are important for immunity to M. tuberculosis through the provision of Th1 cytokines,  such as IFN-gamma to activate macrophages containing the bacilli and perhaps also the participation of cytotoxic T-cells. The latter may kill macrophages,  which cannot be rescued by cytokines thereby releasing the bacteria to be taken up by fresh young macrophages. They can be activated to become killers.

Multiple choice

Lepromatous leprosy is characterised by ______________.

  1. poor T-cell responses

  2. good cell-mediated immunity

  3. good lepromin dermal response

  4. poor B-cell responses

  5. poor phagocytic ability
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Poor T-cell responses specific for the leprosy bacillus, prevent the host from mounting a killing response and the bacilli grow profusely.

Multiple choice

Which of the following is INCORRECT regarding blood coagulation in human beings?

  1. Platelets are the fragments of megakaryocytes.

  2. Primary haemostasis initially involves vasodailation.

  3. Platelet activation stimulates production of thromboxane.

  4. Fibrin monomers gets cross-linked by factor XIIIa.

  5. Clotting is initiated by exposure of tissue factor-bearing cells to plasma clotting factors.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Primary haemostasis initially involves vasoconstriction in response to vascular damage, which limits blood loss, and subsequent platelet adhesion to the damaged area and activation due to exposure of subendothelial matrix.

Multiple choice

Which among the following statements does not characterises an idiotype?

  1. It is independent of the constant region of the T-cell receptor.

  2. An epitope is an antigenic determinant.

  3. Idiotype is sometimes used to describe the collection of multiple idiotopes.

  4. The idiotype describes the distinctive sequence and region that makes any immunoglobing.

  5. The idiotype defines the surface and properties of the constant region of antigen receptors of T cells.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Idiotype defines the surface and properties of the variable region and of antigen receptors of T cells. Thus, determining the antigen specificity and therefore the idiotope of the molecule.