Q.71
Which of the following is used in scintillation detector ?
a)
Sodium bromide b) Naphthlene
c)
Anthracene d) Lead sulphate
Ans
71. D, A scintillator is a
material that exhibits scintillation — the property of luminescencewhen
excited by ionizing radiation. Luminescent materials, when struck by an
incoming particle, absorb its energy and scintillate, (i.e., re-emit the
absorbed energy in the form of light).Sometimes, the excited state is metastable,
so the relaxation back down from the excited state to lower states is delayed
(necessitating anywhere from a few microseconds to hours depending on the
material): the process then corresponds to either one of two phenomena,
depending on the type of transition and hence the wavelength of the emitted
optical photon: delayed fluorescence or phosphorescence, also called
after-glow.
Applications for scintillators
Scintillators are
used by the American government as Homeland Security radiation detectors.
Scintillators can also be used in neutron and high energy particle physics
experiments, new energy resource exploration, X-ray security, nuclear cameras,
computed tomography and gas exploration. Other applications of scintillators
include CT scanners and gamma cameras in medical diagnostics, and screens in
older style CRT computer monitors and television sets.
The use of a
scintillator in conjunction with a photomultiplier tube finds wide use in hand-held
survey meters used for detecting and measuring radioactive contamination and
monitoring nuclear material. Scintillators generate light in fluorescent tubes.
Scintillation detectors are also used in the petroleum industry as detectors
for Gamma Ray logs.
The
scintillation properties of lead sulfate (PbSO4), a scintillator
that shows promise as a high-energy photon detector.
Q.72
Which of the following is incorrect about Innate Immunity?
a)
Non specific
b)
Invade Foreign microorganism
c)
provide immunity which is not affected by infection
d)
Give active immunity
Ans 72. C, The innate immune system,
also known as non-specific immune system and first line of defense, is a
subsystem of the overall immune system that comprises the cells and mechanisms
that defend the host from infection by other organisms in a non-specific
manner. This means that the cells of the innate system recognize and respond to
pathogens in a generic way, but, unlike the adaptive immune system (which is
found only in vertebrates), it does not confer long-lasting or protective
immunity to the host. Innate immune systems provide immediate defense against
infection, and are found in all classes of plant and animal life. They include
both humoral immunity components and cell-mediated immunity components.
The innate immune
system is an evolutionarily older defense strategy, and is the dominant immune
system found in plants, fungi, insects, and primitive multicellular organisms.
The major
functions of the vertebrate innate immune system include:
- Recruiting immune cells to sites of infection, through the production of chemical factors, including specialized chemical mediators, called cytokines
- Activation of the complement cascade to identify bacteria, activate cells and to promote clearance of antibody complexes or dead cells
- The identification and removal of foreign substances present in organs, tissues, the blood and lymph, by specialised white blood cells
- Activation of the adaptive immune system through a process known as antigen presentation
- Acting as a physical and chemical barrier to infectious agents.
The
innate leukocytes include: Natural killer cells, mast cells, eosinophils,
basophils;
and the phagocytic cells including macrophages, neutrophils,
and dendritic cells, and function within the immune system by identifying and
eliminating pathogens that might cause infection.
Q.73
Black fluid is
a)
Homogenous coaltar acid solution
b)
Suspension of activated charcoal
c)
Cresol with soap solution d)
Non of these
Ans 73. A, Black fluids.–These shall be homogeneous dark brown solution
of coal tar acid or similar acids derived from petroleum with or without
hydrocarbon, and/or other phenolic compounds, and their derivatives and a
suitable emulsifier.
Q.74
Restriction endonuclease is used in recombinant DNA technology in ………reaction
a)
Type I b) Type II c) Type III d) Type III
Ans
74. B, A restriction enzyme
(or restriction endonuclease) is an enzyme that cuts DNA at or near
specific recognition nucleotide sequences known as restriction sites. Restriction
enzymes are commonly classified into three types, which differ in their
structure and whether they cut their DNA substrate at their recognition site,
or if the recognition and cleavage sites are separate from one another. To cut
DNA, all restriction enzymes make two incisions, once through each
sugar-phosphate backbone (i.e. each strand) of the DNA double helix.
Q.75
What is the weight of rectal suppository?
a)
3-5 g b) 4 g c) 2 g d) 6 g
Ans
75. C, Rectal suppositories for
adults are tapered at one end and usually weigh about 2 grams. Infant rectal
suppositories usually weight about 1 gram or about half that of adult
suppositories.
Q.76
Fusogen used in hybridoma of monoclonal Antibodies
a)
Polyethylene glycol b) Tweeen 40 c) SDS d) Tween 80
Ans
76. A, Polyethylene glycol (PEG) is
used as a fusogen to obtain hybridomas for monoclonal antibody production.
Induces cell hybridization.
Polyethylene
glycol is also commonly used to fuse B-cells with myeloma cells in monoclonal
antibody production.
Q.77
Prophase generation in DNA ligase
a)
. T4 bacteriophase b) Virus c) Bacteria d) Fungi
Ans
77. A, The DNA ligase from bacteriophage
T4 is the ligase most-commonly used in laboratory research.
Q.78
Engulfment of memberanous organ is done with
a)
Lysosome b)
Endoplasmic reticulum
c)
Mesosome d) Golgi apparatus
Ans
78. C
Q.79
Which of the following release cytolytic T4 prolierating cells that
is used in cancer
a)
IL1 b) IL6
c) IL8
d) IL2
Ans
79. D, IL-2 (Interleukin 2)
is manufactured using recombinant DNA technology and is marketed as a protein
therapeutic called Proleukin by Prometheus Laboratories, Inc. It has been
approved by the Food and Drug Administration (FDA) for the treatment of cancers
(malignant melanoma, renal cell cancer) in large intermittent toxic doses, and
is in clinical trials for the treatment of chronic viral infections, and as a
booster (adjuvant) for vaccines. The use of large, toxic doses of IL-2 given
every 6–8 weeks in HIV therapy, similar to its use in cancer therapy, has been
found recently to be ineffective in preventing progression to an AIDS diagnosis
in two large clinical trials. However, that does not mean that the drug is
ineffective in improving T-cell count. Many persons who underwent IL-2 therapy
enjoyed dramatic improvement in T-cell count, as well as overall health. But
the FDA determined that the risks and costs (experience of side-effects)
outweighed those benefits.
Q.80
Which is not serological species of Vibrio cholera
a)
Inaba b) Ogava c) Hejikoma d) Saukton
Ans
80. D, Vibrio cholerae
is a Gram-negative, comma-shaped bacterium. Some strains of V. cholerae
cause the disease cholera. V. cholerae is a facultative anaerobic
organism and has a flagellum at one cell pole.
El
Tor
is the name given to a particular strain of the bacterium Vibrio
cholerae, the causative agent of cholera. Also known as V.
cholera biotype eltor, it has been the dominant strain in the seventh
global pandemic. It is distinguished from the classic strain at a genetic
level, although both are in the serogroup O1 and both contain Inaba, Ogawa and Hikojima serotypes.
It is also distinguished from classic biotypes by the production of hemolysins.
No comments:
Post a Comment