Which one of the following statements is true? 

• The specific rotation of enantiomers will be identical 

• The rate constant of a first order reaction has only time but no concentration units

• The value of pH + pOH depends on temperature 

• The bond disassociation energy (kJ/mol) of –C–C– will be greater than –C ≡C– 

Which one of the following statements on protein conformation is NOT true?

• Dihedral angles of side-chains in amino acids are depicted in the Ramachandran plot

• Infrared spectroscopy can be used to deduce hydrogen bonding in peptides

• Three dimensional structures of protein composed of ~100 amino acids can be obtained by nuclear magnetic resonance spectroscopy

• Globular proteins have α-helical and β-sheet components. 

Choose the correct answer from the following statements on biosynthesis

• In the biosynthesis of palmitate, all the carbon atoms are derived from activated malonate 

• The amino acids Met, Thr, Lys, Ile, Val and Leu are biosynthesized from oxaloacetate and pyruvate in most bacteria 

• Alanine is a major precursor for the biosynthesis of porphyrin

• Tryptophan is converted to L-DOPA in the biosynthesis of epinephrine 

Which one of the following statements on nucleic acids is NOT true? 

• The conformation of ribose in DNA is α-2'-deoxy-D-ribofuranose

• Hydrolysis of RNA takes place under alkaline conditions unlike DNA, as the 2'-hydroxyl in RNA acts as a nucleophile in an intramolecular displacement

• DNA can occur in different three-dimensional forms 

• In DNA, deamination of cytosine to uracil can occur in a non-enzymatic manner 

5.

A rectangular photo frame of size 30cm× 40cm has a photograph mounted at the centre leaving a 5cm border all around. The area of the border is

• 600 cm²

• 350 cm²

• 400 cm²

• 700 cm²

At birthday, every child gets 2 chocolates, every mother gets 1 chocolates, while no fathers gets a chocolate. In total 69 persons get 70 chocolates. If the number of children is half of the total number of mothers and fathers put together, then how many fathers are there?

• 22

• 23

• 24

• 69

Following are statements on β-turns:

(a) all the 20 coded amino acids have equal propensity to form β-turns.

(b) Pro cannot occur in β-turns

(c)Pro-Gly sequence strongly favours β-turns.

(d) In Asn-Gly β-turns, Asn can have positive Φ, Ψ values.

• (b), (d)

• (a), (c)

• (a), (d)

• (c), (d)

What is the significance of upwelling zone for marine ecosystems?

• It is responsible for uniformity of temperature in ocean to support the marine life

• It brings nutrients from deeper zones to relatively nutrient poor oceans surface thus increasing marine producity.

• It is responsible for uniform oxygenation of marine waters thus increasing marine productivity

• It helps in circulating decomposers from the bottom of ocean to surface for proper decomposition of dead material on the surface

Given below in column A are schematic representation of three types of pairwise species interaction and the name of some interaction are in column B

Select the best match for interaction between column A and B in each schematic figure.

• A-(iii), B-(ii), C-(iv)

• A-(iv), B-(ii), C-(iii)

• A-(ii), B-(iv), C-(i)

• A-(iii), B-(i), C-(ii)

Consider a single locus with 2 alleles which are at Hardy-weinberg equilbrium. If the frequency of one the homozygous genotypes is 0.64, what is the frequency of heterzygotes in the population?

• 0.16

• 0.20

• 0.32

• 0.36