11. The two main differences between $$RNA$$ and $$DNA$$ are
A
ribose sugar and thymine in $$RNA$$
B
deoxyribose sugar and uracil in $$DNA$$
C
ribose sugar and uracil in $$RNA$$
D
deoxyribose sugar and guanine in $$DNA$$
Answer :
ribose sugar and uracil in $$RNA$$
12.
Amino acids are classified as acidic, basic or neutral depending upon the relative number of amino and carboxyl groups in their molecule. Which of the following are acidic?
\[\begin{align}
& \left( \text{i} \right){{\left( C{{H}_{3}} \right)}_{2}}CH\underset{\begin{smallmatrix}
|\,\,\,\,\,\, \\
N{{H}_{2}}\,\,
\end{smallmatrix}}{\mathop{-CH-}}\,COOH \\
& \left( \text{ii} \right)HOOC-C{{H}_{2}}-C{{H}_{2}}\underset{\begin{smallmatrix}
|\,\,\,\,\,\, \\
N{{H}_{2}}\,\,
\end{smallmatrix}}{\mathop{-CH-}}\,COOH \\
& \left( \text{iii} \right){{H}_{2}}N-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-COOH \\
& \left( \text{iv} \right)HOOC-C{{H}_{2}}\underset{\begin{smallmatrix}
|\,\,\,\,\,\, \\
N{{H}_{2}}\,\,
\end{smallmatrix}}{\mathop{-CH-}}\,COOH \\
\end{align}\]
A
(ii) and (iv)
B
(iii) and (iv)
C
(i) and (ii)
D
(ii) and (iii)
Answer :
(ii) and (iv)
13. Denaturation of protein leads to loss of its biological activity by
A
formation of amino acids
B
loss of primary structure
C
loss of both primary and secondary structure
D
loss of both secondary and tertiary structures
Answer :
loss of both secondary and tertiary structures
14. Which base is present in $$RNA$$ but not in $$DNA$$ ?
A
Guanine
B
Cytosine
C
Uracil
D
Thymine
Answer :
Uracil
15. Cellulose present in plants act as a food for cattle but not for human beings because
A
human body does not contain cellulose hence cellulose cannot be broken into $$D$$ - glucose
B
human saliva cannot break down plant cellulose in small pieces
C
bile juice present in cattle helps them to digest cellulose
D
human beings have a smaller stomach than cattle
Answer :
human body does not contain cellulose hence cellulose cannot be broken into $$D$$ - glucose
16. The melting points of amino acids are higher than the corresponding halo-acids because
A
amino acids exist as zwitter ions resulting in strong dipole - dipole attraction
B
amino acids are optically active
C
due to higher molecular mass of $$ - N{H_2}$$ group molecular mass of amino acids is higher
D
they interact with water more than halo-acids and have salt like structure
Answer :
amino acids exist as zwitter ions resulting in strong dipole - dipole attraction
17. Deficiency of vitamin $$E$$ causes
A
rickets
B
scurvy
C
muscular weakness
D
beri-beri
Answer :
muscular weakness
18. The $$\alpha $$ - amino acid which contains the aromatic side chain is
A
proline
B
tyrosine
C
valine
D
serine
Answer :
tyrosine
19. $$RNA$$ is a
A
Single helix strand
B
double helix strand
C
right hand twisted double helix strand
D
triple helix strand
Answer :
Single helix strand
20. Which of the following is correct statement?
A
Starch is a polymer of $$\alpha $$ - glucose
B
Amylose is a component of cellulose
C
Proteins are composed of only one type of amino acid
D
In cyclic structure of fructose, there are four carbons and one oxygen atom
Answer :
Starch is a polymer of $$\alpha $$ - glucose