AIPGE 2011: All Questions With Options & References

Discussion in 'NEET 2013 All india Exam' started by Guest, Jan 10, 2011.

  1. Guest

    Guest Guest

    1. Best test/Gold standard test for assessing betaHCG function/action?
    A. Radioimmunoassay/Bioassay

    2. Superior vena caval syndrome is most commonly caused by?
    C. Non small cell lung ca

    3.-Which among the following is not used to treat alcohol intoxication?

    4. Which among the following is the most common fungal infection seen in immuno competent patients?
    A. Aspergillus/B. Candida
  2. Guest

    Guest Guest

    284. All are true regarding phagocytosis by protozoa except?
    A. Amoeba n other unicellular org make their living out of it
    B. Phagocytose particles of <0. 5 microns size
    C. Phagocytose particles of > 0.5 microns size
    D. Digestion occurs within phagolysosomes

    Endocytosis pathways could be subdivided into four categories: namely, clathrin-mediated endocytosis, caveolae, macropinocytosis, and phagocytosis.[2]

    Clathrin-mediated endocytosis is mediated by small (approx. 100 nm in diameter) vesicles that have a morphologically characteristic crystalline coat made up of a complex of proteins that mainly associated with the cytosolic protein clathrin. Clathrin-coated vesicles (CCVs) are found in virtually all cells and from domains of the plasma membrane termed clathrin-coated pits. Coated pits can concentrate large extracellular molecules that have different receptors responsible for the receptor-mediated endocytosis of ligands, e.g. low density lipoprotein, transferrin, growth factors, antibodies and many others.
    Caveolae are the most common reported non-clathrin coated plasma membrane buds, which exist on the surface of many, but not all cell types. They consist of the cholesterol-binding protein caveolin (Vip21) with a bilayer enriched in cholesterol and glycolipids. Caveolae are small (approx. 50 nm in diameter) flask-shape pits in the membrane that resemble the shape of a cave (hence the name caveolae). They can constitute up to a third of the plasma membrane area of the cells of some tissues, being especially abundant in smooth muscle, type I pneumocytes, fibroblasts, adipocytes, and endothelial cells.[3] Uptake of extracellular molecules is also believed to be specifically mediated via receptors in caveolae.
    Macropinocytosis, which usually occurs from highly ruffled regions of the plasma membrane, is the invagination of the cell membrane to form a pocket, which then pinches off into the cell to form a vesicle (0.5–5 µm in diameter) filled with large volume of extracellular fluid and molecules within it (equivalent to ~100 CCVs). The filling of the pocket occurs in a non-specific manner. The vesicle then travels into the cytosol and fuses with other vesicles such as endosomes and lysosomes.[4]
    Phagocytosis is the process by which cells bind and internalize particulate matter larger than around 0.75 µm in diameter, such as small-sized dust particles, cell debris, micro-organisms and even apoptotic cells, which only occurs in specialized cells. These processes involve the uptake of larger membrane areas than clathrin-mediated endocytosis and caveolae pathway.

Share This Page