Life Sciences
GATE XL year:2020 PYQs
Build your understanding with focused practice from past exam papers.
Questions 21–30 of 125. Imported answers require independent review unless marked reviewed.
Question 11
Open questionXL-PMCQ2 marksNeeds review
Which one of the following hexoses will give an osazone that has a different melting point from that of the osazone obtained from D (+) glucose?
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Open questionXL-PNAT2 marksNeeds review
A molecule in solution crystallizes into two different crystal forms with rate constants of 0.02 s
and 0.13 s
. If the crystallization is assumed to be under kinetic control, then the half-life (in seconds, rounded off to one decimal place) of the molecule is _________.Log in to check the answer
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Open questionXL-PNAT2 marksNeeds review
The standard potential (
) for a cell reaction given below is +0.7 V. The standard reaction free energy (
) for this cell is ______ kJ mol
(correct up to two decimal places). (Given: Faraday constant, F = 96500 C mol
)Au
(aq) + 3 Ag (s)
Au (s) + 3 Ag
(aq)Log in to check the answer
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Open questionXL-PNAT2 marksNeeds review
The activation energy (
) estimated for a reaction from the Arrhenius equation is 21 kJ mol
. If the frequency factor is assumed to be independent of temperature, then the ratio of the rate constants determined at 298 K and 260 K is ________ (rounded off to two decimal places). (Given: Gas constant, R = 8.315 J K
mol
)Log in to check the answer
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Open questionXL-PNAT2 marksNeeds review
At a given pressure, a substance is heated from 2000 K to 2600 K. If the entropy of the substance is 60 J K
mol
, and is assumed to be constant over the given temperature range, then the change in the chemical potential (in kJ mol
) of the substance is ____________.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 1
Open questionXL-QMCQ1 markNeeds review
Which one of the following hormones initiates a signaling cascade by directly binding to an intra-cellular receptor?
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Which one of the following bonds is NOT present in ATP?
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The reaction involved in the direct conversion of L-phenylalanine to L-tyrosine is
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The human major histocompatibility complex (MHC) is
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Har Gobind Khorana and Marshal Nirenberg elucidated the genetic code by using a cell-free protein synthesizing system. It was found that poly(U) and poly(C) result in the synthesis of poly(L-Phe) and poly(L-Pro), respectively. Based on these observations, which one of the following conclusions is correct?
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