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

What are immune checkpoints?

  1. Molecules that regulate the immune response

  2. Molecules that activate the immune response

  3. Molecules that suppress the immune response

  4. Molecules that are expressed on cancer cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Immune checkpoints are molecules that regulate the immune response. These molecules can be expressed on immune cells or cancer cells, and they can either activate or suppress the immune response.

Multiple choice

What are the main types of tumor antigens?

  1. Mutated proteins

  2. Overexpressed proteins

  3. Proteins that are normally expressed in low levels

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Tumor antigens can be classified into three main types: mutated proteins, overexpressed proteins, and proteins that are normally expressed in low levels. Mutated proteins are proteins that have been altered due to mutations in the DNA of cancer cells. Overexpressed proteins are proteins that are expressed at higher levels in cancer cells compared to normal cells. Proteins that are normally expressed in low levels are proteins that are expressed at low levels in normal cells, but are expressed at higher levels in cancer cells.

Multiple choice

Which immune cells are primarily responsible for recognizing and destroying cancer cells?

  1. Cytotoxic T cells

  2. Natural killer cells

  3. Helper T cells

  4. Regulatory T cells
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cytotoxic T cells are a type of immune cell that is primarily responsible for recognizing and destroying cancer cells. These cells can recognize tumor antigens presented on the surface of cancer cells and kill them through the release of cytotoxic molecules.

Multiple choice

Which of the following is an example of an immune checkpoint molecule?

  1. PD-1

  2. CTLA-4

  3. ICOS

  4. CD28
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

PD-1 (Programmed cell death protein 1) is an example of an immune checkpoint molecule. It is expressed on the surface of T cells and plays a role in regulating the immune response. In cancer, PD-1 can interact with its ligand PD-L1, which is expressed on cancer cells, leading to the suppression of T cell activity and allowing cancer cells to escape immune surveillance.

Multiple choice

What is the significance of tumor-infiltrating lymphocytes (TILs) in cancer?

  1. They indicate a strong anti-tumor immune response

  2. They are associated with poor prognosis

  3. They are not relevant to cancer development or progression

  4. They promote tumor growth and metastasis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Tumor-infiltrating lymphocytes (TILs) are immune cells, such as T cells, that infiltrate and accumulate within the tumor microenvironment. The presence of TILs is often associated with a strong anti-tumor immune response and a better prognosis for cancer patients. TILs can recognize and attack cancer cells, contributing to tumor regression and improved patient outcomes.

Multiple choice

What is the structure of a BCR?

  1. A single immunoglobulin molecule

  2. A complex of immunoglobulin molecules and other proteins

  3. A transmembrane protein

  4. A cytoplasmic protein
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

BCRs are composed of a membrane-bound immunoglobulin molecule, called the antigen-binding fragment (Fab), and a transmembrane protein, called the Fc fragment. The Fab fragment is responsible for binding to antigens, while the Fc fragment is responsible for signaling to the B cell.

Multiple choice

How many different types of BCRs can a single B cell express?

  1. One

  2. Two

  3. Several

  4. Hundreds
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A single B cell can express several different types of BCRs, each with a different specificity for antigen. This allows B cells to recognize a wide range of different antigens.

Multiple choice

What happens when a BCR binds to an antigen?

  1. The B cell is activated

  2. The B cell produces antibodies

  3. The B cell differentiates into a memory B cell

  4. The B cell dies
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When a BCR binds to an antigen, the B cell is activated. This activation process leads to the production of antibodies and the differentiation of B cells into memory B cells.

Multiple choice

What is the difference between a BCR and an antibody?

  1. BCRs are expressed on the surface of B cells, while antibodies are secreted by B cells

  2. BCRs are specific for a single antigen, while antibodies can recognize multiple antigens

  3. BCRs are composed of immunoglobulin molecules, while antibodies are composed of different types of proteins

  4. BCRs are involved in the activation of B cells, while antibodies are involved in the effector phase of the immune response
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

BCRs are expressed on the surface of B cells and are responsible for recognizing and binding to antigens. Antibodies are secreted by B cells and are responsible for neutralizing pathogens and activating other immune cells.

Multiple choice

What is the role of B cells in the adaptive immune response?

  1. To produce antibodies

  2. To activate T cells

  3. To help T cells differentiate into memory T cells

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

B cells play a critical role in the adaptive immune response by producing antibodies, activating T cells, and helping T cells differentiate into memory T cells.

Multiple choice

What is the role of B cells in the innate immune response?

  1. To produce antibodies

  2. To activate T cells

  3. To help T cells differentiate into memory T cells

  4. None of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

B cells are not involved in the innate immune response.

Multiple choice

What is the role of B cells in autoimmune diseases?

  1. To produce antibodies against self-antigens

  2. To activate T cells that attack self-tissues

  3. To help T cells differentiate into memory T cells that attack self-tissues

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In autoimmune diseases, B cells can produce antibodies against self-antigens, activate T cells that attack self-tissues, and help T cells differentiate into memory T cells that attack self-tissues.

Multiple choice

What is the role of B cells in cancer?

  1. To produce antibodies against cancer cells

  2. To activate T cells that attack cancer cells

  3. To help T cells differentiate into memory T cells that attack cancer cells

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

B cells can play a role in cancer by producing antibodies against cancer cells, activating T cells that attack cancer cells, and helping T cells differentiate into memory T cells that attack cancer cells.

Multiple choice

What is the role of B cells in transplantation?

  1. To produce antibodies against donor antigens

  2. To activate T cells that attack donor tissues

  3. To help T cells differentiate into memory T cells that attack donor tissues

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In transplantation, B cells can produce antibodies against donor antigens, activate T cells that attack donor tissues, and help T cells differentiate into memory T cells that attack donor tissues.

Multiple choice

What is the role of B cells in allergy?

  1. To produce antibodies against allergens

  2. To activate T cells that attack allergens

  3. To help T cells differentiate into memory T cells that attack allergens

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In allergy, B cells can produce antibodies against allergens, activate T cells that attack allergens, and help T cells differentiate into memory T cells that attack allergens.