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