Hello sir I want to know about TIFR GS Biology so here can you please give me Answer Key for practice ?

Hey as The Tata Institute of Fundamental Research ( TIFR ) is India’s premier institution for advanced research in fundamental sciences. The Institute runs a graduate program leading to the award of Ph.D. degree, as well as M.Sc. and Integrated Ph.D. in certain with subjects.

Subjects

Chemistry

Physics

Mathematics

Biology

Computer & System Science

Here I am giving you TIFR GS Biology paper

If the ratio of (A + G)/(T + C) in one strand of DNA is 0.70, what is the same ratio in the complementary strand?
a. 0.70
b. 1.43
c. 0.35
d. 0.30

DNA was isolated from wild type (W) and mutant (M) E.coli cells and separated by
density gradient centrifugation technique. DNA from M strain acquired a lower
position. This indicates that the mutation is caused by:
a. Deletion
b. Insertion
c. Missense mutation
d. Point mutation

Cotrans formation between two genes is more likely if they are:
a. close to one another
b. far apart from one another
c. both next to the F factor
d. both oriented in the same direction

How is it possible for ions to be at equilibrium across a plasma membrane and yet not be at the same concentration on both sides?
a. Because the mobility of ions is restricted across the plasma membrane
b. Because there is a charge difference across the plasma membrane
c. Because of voltage gated ion channels in the plasma membrane
d. Because of the presence of leak ion channels in the plasma membrane

One of the most accurate methods for placing an individual at the scene of a crime
is DNA finger printing. This involves the following steps:
(1)Denaturation of DNA
(2)Recognition of repetitive sequences
(3)Gel electrophoresis
(4)Digestion of DNA with restriction endonucleases
(5)Use of a radiolabeled DNA probe
(6)Transfer of DNA to nitrocellulose
(7)Extraction of DNA

The correct order of these steps is:
a.(7, 1, 3, 6, 4,5, 2)
b.6, 7, 1, 3, 4, 5, 2)
c.(7, 4, 3, 1, 6, 5, 2)
d.(7, 3, 6, 4, 2, 5, 1)

. Animal cells are labeled with radioactive amino acids. In which of the following
molecules would you detect radioactivity:

I. Proteins
II. RNA
III. Ribosomes
IV. Glycolipids
a. I
b. I & III
c. II
d. I & IV

. Protein gels (SDSPAGE) are usually run vertically whereas DNA gels (agarose)
are usually run horizontally. A student desires to run a protein gel horizontally and a
DNA gel vertically. Which of the following statements will best explain his results?

a. The protein gel experiment will not work because the proteins need gravity to move
. The DNA gel will be fine.
b. Both the protein and the DNA gel experiments will not work. Protein gels have to be run vertically and DNA gels have to be run horizontally.
c. Both the protein and the DNA gel experiments will work as the principles behind their functioning do not depend upon gravity.
d. The protein gel experiment will work but the DNA gel experiment will not.

The molar absorption coefficient (extinction coefficient) of NADH at 340nm is 6220
l/mol/cm, whereas that of NAD at the same wavelength is 0. What absorbance will be
observed when 340nm light passes through a 1 cm cuvette containing 10 micro
molar NADH and 10 micromolar NAD?
a. 0.031
b. 0.062
c. 0.31
d. 0.62

. The different beak morphologies of Darwin’s Finches on the Galapagos Islands is
best explained by

a. Genetic variation
b. Dietary differences
c. Different habitats
d. All of the above

Because of widespread pollution in England during the industrial revolution,
areas near factories became darkened with soot. During this period, a darker form of the peppered moth (Biston betularia) found to be more predominant over the lighter form This was because
a. The darker pigments allowed the moths to resist the effects of soot
b. The pollutants caused toxicity, resulting in darker wings
c. The darker form was better camouflaged from predators
d. The food source of the lighter form was wiped out

. Let us consider three independently assorting autosomal genes in Drosophila: A,
B and C. What is the probability that a female of genotype AaBBCc when crossed to
a male of AAbbCc will produce an
offspring of genotype AABbcc?
a. 1/2
b. 1/4
c. 1/8
d. 1/16

Two students independently isolated lactate dehydrogenase from chicken heart
and measured its activity as a function of substrate concentration, each determining
Vmax and Km of their own preparation. They both got the same Km but different
Vmax. One student said they had isolated different forms of the same enzyme, the
other said they had isolated the same form. To resolve their argument they must

a. Measure the molecular weight of the enzyme
b. Measure enzyme activity as a function of time after addition
of substrate
c. Determine the turnover number of each preparation
d. All of the above