Tag: defence against infectious disease
Questions Related to defence against infectious disease
Platelets are
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Source of growth factors
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Involved in hemostasis
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Lead to blood clots
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All of the above
Platelets are parts of the blood that help the blood clot. They are smaller than red or white blood cells. Platelets are a natural source of growth factors. They circulate in the blood of mammals and are involved in hemostasis, leading to the formation of blood clots. Platelets release thread-like fibers to form these clots.
The process of blood clotting does not require
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Sodium ions
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Calcium ions
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Prothrombin
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Vitamin K
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Platelets
Blood clotting is the process by which blood changes from liquid to gel and stop bleeding. When the blood vessels get injured, platelets in blood produces prothrombin in the presence of vitamin K. The prothrombin then converts into the thrombin (active form) in the presence of thrombokinase and calcium ions. This thrombin then converts fibrinogen (inactive) into the fibrin (active). Fibrin thread then plugs the damaged part and appear like a clot. Thus, the correct answer is option A.
Name of cells which help in clotting of blood in mammals ____________.
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Platelets
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Thrombocytes
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Lymphocytes
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Monocytes
Platelet, also called thrombocyte, colourless, nonnucleated blood component that is important in the formation of blood clots (coagulation). Platelets are found only in the blood of mammals.
Blood platelets occur in the blood of ____________.
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Birds
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Mammals
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Reptiles
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Amphibians
Only mammals have platelets, tiny cells without nuclei that are responsible for plugging the leaks in the blood vessels. Other animals use more conventional systems of hemostasis. Some marine invertebrates have a single type of blood cell, responsible for hemostasis, but also for other types of defences. Non-mammalian vertebrates have specialized nucleated thrombocytes to do the job.
Blood platelets are.
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Nucleated cells
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Non-nucleated cells
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Non-nucleated cell fragments
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Nucleated cell fragments
Platelets are small, non-nucleated cells that are derived from megakaryocytes in the bone marrow. Platelets circulate in the blood, sense damage to a blood vessel and accumulate at these sites, where they initiate blood clotting. They are fragments of cytoplasm that are derived from the megakaryocytes of the bone marrow.
Instead of platelets, the non-mammals possess clotting factor in.
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Nucleated cells called thrombocytes
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RBC
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WBC
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Plasma
Only mammals have Platelets. Non-mammals possess thrombocytes which are nucleated cells which have been shown to have a haemostatic function paralleling that of mammalian platelets.
Megakaryocytes.
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Produce leucocytes
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Form blood platelets
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Are called bone cells
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Are carriers of oxygen
A megakaryocyte is a large bone marrow cell with a lobated nucleus responsible for the production of blood thrombocytes (platelets), which are necessary for normal blood clotting.
The life span of thrombocytes is
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4 to 5 weeks
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3 to 4 weeks
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3 to 7 days
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None of these
$1$ li. of oxygenated blood can deliver how much amount of $O _2$ to the tissue under normal conditions.
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$4$ ml
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$50$ ml
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$20$ ml
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$159$ ml
Ornithine cycle helps to remove _______ from blood.
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Urea
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$NH _3$
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Uric acid
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Arginine