NEET Previous Year Questions (2014-21): Biomolecules Notes | Study Chemistry Class 12 - NEET

Q.1. The RBC deficiency is deficiency disease of:      (2021)
A: Vitamin B₁
B: Vitamin B₂
C: Vitamin B₁₂
D: Vitamin B₆
Ans: C
Solution: Vitamin B12 deficiency → Pernicious anaemia (RBC deficient in heamoglobin).

Q.2. Sucrose on hydrolysis gives:      (2020)
A: α-D-Glucose + β-D-Fructose
B: α-D-Fructose + β-D-Fructose
C: β-D-Glucose + α-D-Fructose
D: α-D-Glucose + β-D-Glucose
Ans: A
Solution:


Q.3. Which of the following is a basic amino acid?       (2020)
A: Tyrosine 
B: Lysine 
C: Serine
D: Alanine
Ans: B
Solution:

Basic part is more than acidic part so lysine is basic amino acid.

Q.4. The non-essential amino acid among the following is:    (2019)
A: Valine
B: Leucine
C: Alanine
D: Lysine
Ans: C

Q.5. The difference between amylose and amylopectin is    (2018)
A: Amylopectin have 1 → 4 α-linkage and 1→ 6α-linkage
B: Amylose have 1 → 4 α-linkage and 1→ 6β-linkage
C: Amylopectin have 1 → 4 α-linkage and 1→ 6β-linkage
D: Amylose is made up of glucose and galactose
Ans: A
Solution:
Amylose is long unbranched chain with α-D-Glucose with held by C1–C4 glucosidic linkage whereas amylopectin is branched chain polymer ofα-D glucose unit in which chain is formed by C1–C4 glycosidic linkage while branching occurs by C1–C6 glucosidic linkage.

Q.6. Which of the following compounds can form a zwitterion ?    (2018)
A: Aniline
B: Acetanilide
C: Benzoic acid
D: Glycine
Ans: D
Solution:
The molecule which forms zwitter ion is glycine.


Q.7. Which of the following statements is not correct :-     (2017)
A: Ovalbumin is a simple food reserve in egg-white
B: Blood proteins thrombin and fibrinogen are involved in blood clotting
C: Denaturation makes the proteins more active
D: Insulin maintanis sugar level in the blood of a human body
Ans: C

Q.8. In a protein molecule various amino acids are linked together by:    (2016)
A: dative bond
B: α-glycosidic bond
C: β-glycosidic bond
D: peptide bond
Ans: D
Solution:
Two amino acids on the protein are linked by a peptide bond. For example. Glycyl-l-alanine is formed when carboxyl group of glycine combines with the amino group of alanine.

Two amino acids on the protein are linked by a peptide bond. For example. Glycyl-l-alanine is formed when carboxyl group of glycine combines with the amino group of alanine.


Q.9. Which one given below is a non-reducing sugar ?    (2016)
A: Sucrose
B: Maltose
C: Lactose
D: Glucose
Ans: A
Solution:
Sucrose is non-reducing sugar because it has one -CHO group.

Q.10. The correct statement regarding RNA and DNA, respectively is:     (2016)
A: The sugar component in RNA is 2'-deoxyribose and the sugar component in DNA is arabinose.
B: The sugar component in RNA is arabinose and the sugar component in DNA is 2'-deoxyribose.
C: The sugar component in RNA is ribose and the sugar component in DNA is 2'-deoxyribose.
D: The sugar component in RNA is arabinose and the sugar component in DNA is ribose.
Ans: C
Solution:
In DNA, two helically twisted strands connected together by steps. Each strand consists of alternating molecules of deoxyribose at 2'-position and phosphate groups.
On another hand, in RNA, the pentose sugar has an identical structure with deoxyribose sugar except that there is an -OH group instead of -H on carbon atom 2'. Hence it is only called ribose.

Q.11. Which of the following hormones is produced under the condition of stress which stimulates glycogenolysis in the liver of human beings ?    (2014)
A: Adrenaline
B: Estradiol
C: Thyroxin
D: Insulin
Ans: A

Q.12. D(+) glucose reacts with hydroxyl amine and yields an oxime. The structure of the oxime would be:    (2014)
A: