51.
The correct corresponding order of names of four aldoses with configuration given below
respectively, is
A
$$L$$ - erythrose, $$L$$ - threose, $$L$$ - erythrose, $$D$$ - threose
B
$$D$$ - threose, $$D$$ - erythrose, $$L$$ - threose, $$L$$ - erythrose
C
$$L$$ - erythrose, $$L$$ - threose, $$D$$ - erythrose, $$D$$ - threose
D
$$D$$ - erythrose, $$D$$ - threose, $$L$$ - erythrose, $$L$$ - threose
Answer :
$$D$$ - erythrose, $$D$$ - threose, $$L$$ - erythrose, $$L$$ - threose
52. Which of the following diseases is not correctly matched with the vitamins mentioned with it?
A
Vitamin $${B_2}$$ - Cracking of lips
B
Vitamin $$C$$ - Bone deformities
C
Vitamin $$D$$ - Osteomalacia
D
Vitamin $$A$$ - Night blindness
Answer :
Vitamin $$C$$ - Bone deformities
53. The pyrimidine bases present in $$DNA$$ are
A
cytosine and thymine
B
cytosine and uracil
C
cytosine and adenine
D
cytosine and guanine
Answer :
cytosine and thymine
54. Which is not a true statement ?
A
$$\alpha $$ - carbon of $$\alpha $$ - amino acid is asymmetric
B
All proteins are found in $$L$$ - form
C
Human body can synthesize all proteins they need
D
At $$pH = 7$$ both amino acids and carboxylic groups exist in the ionised form
Answer :
All proteins are found in $$L$$ - form
55. All of the following statements apply to proteins except
A
Proteins generally have no definite melting point
B
Proteins contain the grouping \[-CONH-\]
C
Proteins have high molecular weight
D
Proteins can only contain the elements $$C,H,O$$ and $$N.$$
Answer :
Proteins can only contain the elements $$C,H,O$$ and $$N.$$
56. Invert sugar is
A
a type of cane sugar
B
optically inactive form of sugar
C
mixture of glucose and galactose
D
mixture of glucose and fructose in equimolar quantities
Answer :
mixture of glucose and fructose in equimolar quantities
57. On hydrolysis of starch, we finally get
A
glucose
B
fructose
C
Both (A) and (B)
D
sucrose
Answer :
glucose
58. An example of biopolymer is
A
teflon
B
neoprene
C
nylon-66
D
$$DNA$$
Answer :
$$DNA$$
59. On boiling the egg, what structural changes are taking place in the egg white?
A
The colour of the egg changes from colourless to white.
B
$${2^ \circ }$$ and $${3^ \circ }$$ structures are destroyed but $${1^ \circ }$$ structure remains intact.
C
$${1^ \circ },{2^ \circ }$$ and $${3^ \circ }$$ structures of egg are destroyed.
D
A reversible change takes place which can be reversed by decreasing the temperature.
Answer :
$${2^ \circ }$$ and $${3^ \circ }$$ structures are destroyed but $${1^ \circ }$$ structure remains intact.
60. The correct statement in respect of protein haemoglobin is that it
A
acts as an oxygen carrier in the blood
B
forms antibodies and offers resistance to diseases
C
enzymes are specific biological catalysts that can normally function at very high temperature $$\left( {T \sim 1000K} \right)$$
D
enzymes are specific biological catalysts that possess well-defined active sites
Answer :
acts as an oxygen carrier in the blood