Practice Start Test

Biomolecules

NEET Biology · 137 questions · Page 8 of 14 · Click an option or "Show Solution" to reveal answer

Q71
Which of the following is not a fat soluble vitamin?
A Vitamin B complex
B Vitamin D
C Vitamin E
D Vitamin A
Correct Answer
Option A
Solution

Vitamin B complex is not a fat soluble vitamin. It is a water soluble vitamin.

Q72
Which one of the following statements is not true regarding (+) lactose?
A On hydrolysis (+) lactose gives equal amount of D(+) glucose and D(+) galactose.
B (+) Lactose is a β\beta -glucoside formed by the union of a molecule of D(+) glucose and a molecule of D(+) galactose.
C (+) Lactose is a reducing sugar and does not exihibit mutarotation.
D (+) Lactose, C 12 H 22 O 11 contains 8-OH groups
Correct Answer
Option C
Solution

(+) Lactose is a reducing sugar and all reducing sugar shows mutarotation.

Q73
Fructose reduces Tollen's reagent due to
A asymmetric carbons
B primary alcoholic group
C secondary alcoholic group
D enolisation of fructose followed by conversion to aldehyde by base
Correct Answer
Option D
Solution

Under alkaline conditions of the reagent, fructose gets converted into a mixture of glucose and mannose (Lobry de Bruyn van Ekenstein rearrangement) both of which contain the –CHO group and hence reduce Tollens’ reagent to give silver mirror test.

Q74
Which one of the following does not exhibit the phenomenon of mutaroation?
A (+) Sucrose
B (+) Lactose
C (+) Maltose
D (−-) Fructose
Correct Answer
Option A
Solution

Sucrose does not show mutarotation.

Only those sugars which have a free aldehyde or ketone group are capable of showing mutarotation.

Q75
The segment of DNA which acts as the instrumental manual for the synthesis of the protein is
A ribose
B gene
C nucleoside
D nucleotide
Correct Answer
Option B
Solution

The DNA sequence that codes for a specific protein is called a Gene and thus every protein in a cell has a corrosponding gene.

Q76
Which of the following hormones contains iodine?
A Testosterone
B Adrenaline
C Thyroxine
D Insulin
Correct Answer
Option C
Solution

Thyroxine contains iodine

Q77
Which of the following is an amine hormone?
A Insulin
B Progesterone
C Thyroxine
D Oxypurin
Correct Answer
Option C
Solution

Thyroxine is an amino hormone.

Q78
In DNA, the complimentary bases are
A adenine and guanine; thymine and cytosine
B uracil and adenine; cytosine and guanine
C adenine and thymine; guanine and cytosine
D adenine and thymine; guanine and uracil.
Correct Answer
Option C
Solution

DNA contains two types of nitrogeneous bases Purine →\to Adenine (A) and guanine (G) Pyrimidine →\to Cytosine (C) and thymine (T) The purine and pyrimidine bases pair only in certain combination.

Adenine pairs with thymine (A : T) by two hydrogen bonds and guanine with cytosine (G : C) by three hydrogen bonds.

Q79
Which of the following vitamins is water-soluble?
A Vitamin E
B Vitamin K
C Vitamin A
D Vitamin B
Correct Answer
Option D
Solution

Vitamin B is water soluble whereas all other are water insoluble.

Q80
RNA and DNA are chiral molecules, their chirality is due to
A chiral bases
B chiral phosphate ester units
C DD-sugar component
D LL-sugar component
Correct Answer
Option C
Solution

Each nucleic acid consists of a pentose sugar a heterocyclic base, and phosphoric acid.

The sugar present in DNA is -D (–) -2-deoxy ribose and the sugar present in RNA is D (–)- ribose.

The chirality of DNA and RNA molecules are due to the presence of sugar components.

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