Q.1
In corn there are 10 chromosomes per set and the species is diploid. A karyotype
was performed from the endosperm cells grown in tissue culture in a medium
containing colchicine. What is the total number of chromosomes in an endosperm
cell after the first round of cell divisions?
(a) 5
(b) 14
(c) 15
(d) 30
Q.2 Three of the
four eukaryotic rRNAs are synthesized from a single transcription unit
consisting of the rDNA. Which one of the following does NOT belong to this
group?
(a) 5.8S
(b) 5S
(c) 18S
(d) 28S
Q.3 When �-[32
P]-ATP is incubated in an eukaryotic cell extract that is capable of
transcription and RNA processing where does the label appear in the m-RNA?
(a) Every phosphate group of the m RNA is
labelled
(b) Only the 5-end of the m RNA is
labelled provided the first base is A
(c) Only the 3-end of the m-RNA is
labelled provided the last base is A
(d) The label does not appear at all in
m-RNA
Q.4 Which particle
converts cholesterol to cholesterol esters?
(a) LDL
(b) Chylomicrons
(c) VLDL
(d) HDL
Q.5 A patient
presents with lethargy and a 10-fold increase in plasma ammonia and glutamine
levels due to a defect in the urea cycle. The build-up of what other metabolite
in the plasma is consistent with a defect in ornithine transcarbamoylase and not
carbamoyl phosphate synthetase I?
(a) Urea
(b) Arginine
(c) Ornithine
(d) Citrulline
Q.6 Tay-Sachs
Disease, characterized by intralysosomal accumulation of the GM2 ganglioside,
results from a deficiency in
(a) Sphingomyelinase.
(b) Galactocerebrosidase.
(c) Glucocerebrosidase.
(d) Hexosaminidase A.
Q.7 Which of the
following assays is currently being used for the detection of Helicobacter
pylori?
(a) Agglutination
(b) Complement fixation
(c) Enzyme-linked immunosorbent assay
(d) Immunodiffusion
Q.8 An individual
was found to be heterolo-gous for IgG1 allotypes 3 and 12. The
different possible IgG1 antibodies produced by this individual will
never have
(a) Two H chains of allotype 12
(b) Two L chains of either Κ or Λ
(c) Two H chains of allotype 3
(d) Two H chains, one of allotype 3 and one of
allotype 12
Q.9 The resting
membrane potential
(a) Occurs only in nerve and muscle cells
(b) Is the same in all cells.
(c) Is oriented so that the cell's interior is
positive with respect to the extracellular fluid.
(d) Requires the separation of most of the cell's
charged particles.
Q.10 Which of the
following is NOT part of Koch's postulates?
(a) The microorganism is never found in healthy
animals.
(b) The microorganisms is always found in diseased
animals.
(c) The microorganism must cause disease in healthy
animals.
(d) The microorganism must secrete a toxin in
culture.
