Multiple Choice QuestionsA student wishes to study the cell structure under a light microscope having 10X eyepiece and 45X objective. He should illuminate the object by which one of the following colours of light so as to get the best possible resolution?
Yellow
Green
Blue
Red
The net pressure gradient that causes the fluid to filter out of the glomeruli into the capsule is
20 mm Hg
75 mm Hg
30 mm Hg
50 mm Hg
Centromere is required for
transcription
crossing over
cytoplasmic cleavage
movement of chromosomes towards poles
Damage to thymus in a child may lead to
a reduction in haemoglobin content of blood
a reduction in stem cell production
loss of antibody mediated immunity
loss of cell mediated immunity
G-6-P dehydrogenase deficiency is associated with haemolysis of
lymphocytes
RBCs
platelets
leucocytes
Which of the following substances, if introduce in the blood stream, would cause coagulation, at the site of its introduction?
Fibrinogen
Prothrombin
Heparin
Thromboplastin
D.
Thromboplastin
Lipoproteinaceous, thromboplastin is released by the injured tissue. It reacts with Ca2+ ions present in blood and forms prothrombinase enzyme. Later, in the presence of Ca2+ ions, it inactivates heparin (anticoagulant) and catalyses prothrombin (inactive plasma protein) into an active thrombin protein.
Thrombin acts as an enzyme and catalyses fibrinogen (soluble plasma protein) into an insoluble fibre like polymer, fibrin. These form a dense network upon the wound and trap blood corpuscles and thus form a clot. This further seals the wound and stops bleeding
In blood vessels, thromboplastin does not release due to which blood does not clot. However, external thromboplastin causes blood clotting at the site of its introduction due to formation of prothrombinase enzyme.
Nucleotide are building blocks of nucleic acids, nucleotide is a composite molecule formed by
(base-sugar-phosphate)n
base-sugar-OH
base-sugar-phosphate
sugar-phosphate
Enzymes, vitamins and hormones can be classified into a single category of biological chemicals, because all of these
enhance oxidative metabolism
are conjugated proteins
are exclusively synthesized in the body of a living organism as at present
help in regulating metabolism
In a man, abducens nerve is injured. Which one ofthe following functions will be affected?
Movement of the eye ball
Swallowing
Movement of the tongue
Movement of the neck
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