1. Which of the following substances is not present in nucleic acids ?
A.
Cytosine
B.
Adenine
C.
Thymine
D.
Guanidine
Answer :
Guanidine
is neither a purine nor a pyrimidine base 2. Night blindness is caused by deficiency of
A.
vitamin $${B_{12}}$$
B.
vitamin $$A$$
C.
vitamin $$C$$
D.
vitamin $$E$$
Answer :
vitamin $$A$$
3. Among the following organic acids, the acid present in rancid butter is :
A.
Pyruvic acid
B.
Lactic acid
C.
Butyric acid
D.
Acetic acid
Answer :
Butyric acid
4. Guanine is an example of
A.
a nitrogenous base
B.
a nucleoside
C.
a nucleotide
D.
a phosphate derivative
Answer :
a nitrogenous base
5. Among the three compounds shown below, two yield the same product on reaction with warm $$HN{O_3}.$$ The exception is :
A.
B.
C.
D.
Answer :
6. Which one of the following chemical units is certainly to be found in enzyme?
A.
B.
C.
D.
Answer :
7. The cell membranes are mainly composed of
A.
carbohydrates
B.
proteins
C.
phospholipids
D.
fats
Answer :
phospholipids
8.
Study the structures of $$\alpha {\text{ - }}D{\text{ - }}\left( + \right)$$ glucopyranose and $$\beta {\text{ - }}D{\text{ - }}\left( + \right)$$ glucopyranose and mark the correct statement.
A.
Structures I and II are enantiomers.
B.
Structures I and II are anomers.
C.
The two structures I and II differ in the configuration of $${C_1}$$ and $${C_4}.$$
D.
Both the structures I and II give 2, 4-$$DNP$$ test.
Answer :
Structures I and II are anomers.
9. The human body does not produce
A.
$$DNA$$
B.
vitamins
C.
hormones
D.
enzymes
Answer :
vitamins
10. Maltose is made up of
A.
two $$\alpha {\text{ - }}D{\text{ - }}$$ glucose
B.
normal $$\beta {\text{ - }}D{\text{ - }}$$ glucose
C.
$$\alpha {\text{ - }}$$ and $$\beta {\text{ - }}D{\text{ - }}$$ glucose
D.
fructose
Answer :
two $$\alpha {\text{ - }}D{\text{ - }}$$ glucose