Tag: cells in immune system
Questions Related to cells in immune system
Which is not a T-lymphocytes?
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Helper
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Suppressor
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Cytotoxic
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Repressor
- A T cell, or T lymphocyte, is a type of lymphocyte (a subtype of white blood cell) that plays a central role in cell-mediated immunity. T cells can be distinguished from other lymphocytes, such as B cells and natural killer cells, by the presence of a T-cell receptor on the cell surface. T-cells are originated from bone marrow and mature in the thymus gland.
- There are 3 main types of T-cells in mammals. They are - cytotoxic cells ( destroy virus-infected cells and tumour cells), helper cells (assist other WBC in immunologic processes including maturation of B cells into plasma cells and memory B cells, and activation of cytotoxic T cells and macrophages and suppressor cells (stop T cell-mediated immunity toward the end of an immune reaction).
What is true about Bt toxin ?
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The concerned Bacillus has antitoxins
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The inactive protoxin gets converted into active form in the insect gut
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Bt protein exists as active toxin in the Bacillus
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The activated toxin enters the ovaries of the pest to sterilize it and thus prevent its multiplication.
Anaplasia is
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Transfer of cancer cells
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Formation of tumour
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Loss of cell adeherence and cell differentioation
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Action of lysosomes over cells
Anaplasia is a condition of cells with poor cellular differentiation, losing the morphological characteristics of mature cells and their orientation with respect to each other and to endothelial cells. Such loss of structural differentiation is especially seen in most, but not all, malignant neoplasms. Hence, Anaplasia is the loss of adherence and cell differentiation.
B-lymphocytes differentiate and mature in
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Bone marrow
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Bursa of Fabricus
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Thymus
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Both A and B
- B cell activation occurs in the secondary lymphoid organs, such as the spleen and lymph nodes.
- After B cells mature in the bone marrow, they migrate through the blood secondary lymphoid organs to which receive a constant supply of antigen through circulating lymph.
- In birds, the bursa of Fabricius is the site of hematopoiesis, a specialized organ that is necessary for B cell development in birds.
- Hence, B-lymphocytes differentiate and mature in Bone marrow and Bursa of Fabricius.
- So, the correct answer is 'Both A and B'.
Cytotoxic T-cells are similar to natural killler cells in secretion of
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Interferons
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Lysozymes
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Perforins
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Prostaglandins
- Perforin is a pore-forming cytolytic protein found in the granules of cytotoxic T lymphocytes (CTL) and Natural Killer cells (NK cells).
- Upon degranulation, perforin binds to the target cell's plasma membrane, and oligomerises in a Ca2+ dependent manner to form pores on the target cell.
- Hence, Cytotoxic T-cells are similar to natural killer cells in the secretion of Perforins.
- So, the correct answer is 'Perforins'.
The site of production of ADA in the the body is _____________.
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Erythrocytes
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Lymphocytes
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Blood plasma
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Osteocytes
Lymphocytes are kind of white blood cells present in the bone marrow. ADA (adenosine deaminase) is an enzyme that is present in lymphocytes and is very important for the immune system to function. Its primary function in humans is the development and maintenance of the immune system.
T-cells in lymph nodes
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occur predominantly in the medullary region
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are only of the cytotoxic type
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are phagocytic
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are absent in Di George syndrome
T cells are so called because they are predominantly produced in the medullary region of thymus. They recognise foreign particles (antigen) by a surface expressed, highly variable, T cell receptor (TCR). There are two major types of T cells: the helper T cell and the cytotoxic T cell. As the names suggest helper T cells ‘help’ other cells of the immune system, whilst cytotoxic T cells kill virally infected cells and tumours. T cells with CD4 molecules bind peptides displayed on MHC II molecules. As discussed earlier, such peptides are derived from phagocytized sources, and thus these T cells interact with only with certain special, phagocytic cells.
Production of antibody molecules by plasma cells requires interactions of and
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Macrophages; plasma cells
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T-helper cells; B-cells
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Stromal cells; B-cells
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T-suppressor cells; plasma cells
Plasma cells are transported by the blood plasma and the lymphatic system. Plasma cells originate at the bone marrow and B cells differentiate into plasma cells that produce antibody molecules closely modeled after the receptors and requires interactions with Helper T cells.
Arrange the following sentences in sequential order.
a) Antigen gets broken down into smaller fragments.
b) An antigen is internalised by phagocytosis.
c) An antigen is attracted by chemotaxis and attaches to the cell surface.
d) Antigen fragments binds to the MHC I and MHC II and gets transported to the membrane.
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b, c , a, d
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c, b, a, d
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b, c , d, a
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b, a , c, d
Plasma cells are
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inactive T-cells carried in the plasma
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B-cells that are actively secreting antibody
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formed from blood plasma
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the same as memory cells
Plasma cells are transported by the blood plasma and the lymphatic system. They originate in the bone marrow: B cells differentiate into plasma cells that produce antibody molecules closely modeled after the receptors of the precursor B cell.