#### 12th Standard Chemistry Biomolecules English Medium Free Online Test One Mark Questions 2020 - 2021

12th Standard

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Chemistry

Time : 00:20:00 Hrs
Total Marks : 20
20 x 1 = 20
1. Which one of the following rotates the plane polarized light towards left?

(a)

D(+) Glucose

(b)

L(+) Glucose

(c)

D(-) Fructose

(d)

D(+) Galactose

2. Assertion: A solution of sucrose in water is dextrorotatory. But on hydrolysis in the presence of little hydrochloric acid, it becomes levorotatory. (AIIMS)
Reason: Sucrose hydrolysis gives unequal amounts of glucose and fructose. As a result of this change in sign of rotation is observed.
Codes:
(a) If both accretion and reason are true and reason is the correct explanation of assertion.
(b) If both assertion and reason are true but reason is not the correct explanation of assertion.
(c) If assertion is true but reason is false.
(d) if both assertion and reason are false.

(a)

If both accretion and reason are true and reason is the correct explanation of assertion

(b)

If both assertion and reason are true but reason is not the correct explanation of assertion

(c)

If assertion is true but reason is false.

(d)

if both assertion and reason are false.

3. In a protein, various amino acids linked together by __________

(a)

Peptide bond

(b)

Dative bond

(c)

$\alpha$-Glycosidic bond

(d)

$\beta$ - Glycosidic bond

4. The correct statement regarding RNA and DNA respectively is __________

(a)

the sugar component in RNA is an arabinos and the sugar component in DNA is ribose

(b)

the sugar component in RNA is 2’-deoxyribose and the sugar component in DNA is arabinose

(c)

the sugar component in RNA is an arabinose and the sugar component in DNA is 2’-deoxyribose

(d)

the sugar component in RNA is ribose and the sugar component in DNA is 2’-deoxyribose

5. Vitamin B2 is also known as __________

(a)

Riboflavin

(b)

Thiamine

(c)

Nicotinamide

(d)

Pyridoxine

6. Among the following L-serine is __________

(a)

(b)

(c)

(d)

7. Which of the following vitamins is water soluble?

(a)

Vitamin E

(b)

Vitamin K

(c)

Vitamin A

(d)

Vitamin B

8. If one strand of the DNA has the sequence ‘ATGCTTGA’, then the sequence of complementary strand would be ___________

(a)

TACGAACT

(b)

TCCGAACT

(c)

TACGTACT

(d)

TACGRAGT

9. Which of the following amino acids are achiral?

(a)

Alanine

(b)

Leucine

(c)

Proline

(d)

Glycine

10. Which among the following is called fruit sugar?

(a)

Glucose

(b)

Fructose

(c)

Sucrose

(d)

Maltose

11. Sucrose contains glucose and fructose linked by

(a)

C1 - C1

(b)

C1-C2

(c)

C1 - C4

(d)

C1 - C6

12. Inversion of sucrose refers to

(a)

oxidation of sucrose

(b)

reduction of sucrose

(c)

hydrolysis of sucrose to glucose and fructose

(d)

polymerisation of sucrose

13. Two amino acids say A, B react to give

(a)

two dipeptides

(b)

three dipeptides

(c)

four dipeptides

(d)

only one

14. Specificity of enzyme is due to

(a)

the sequence of amino acids

(b)

secondary structure

(c)

tertiary structure

(d)

all of the above

15. The storage of energy in plants and animals are

(a)

oils and fats

(b)

proteins

(c)

carbohydrates

(d)

vitamins

16. The number of primary and secondary alcoholic groups in fructose is

(a)

2,3

(b)

3,2

(c)

4,3

(d)

5,4

17. Carbohydrates in which large number of monosaccharide units linked to each other by oxide bridges are

(a)

non-sugars

(b)

polysaccharides

(c)

tetrasaccharides

(d)

both (a) and (b)

18. When starch is heated to 200°C - 250°C, the product is

(a)

dextrin

(b)

caramel

(c)

barley sugar

(d)

cellulose

19. Sucrose contains glucose and fructose linked by

(a)

C1- C1

(b)

C1- C2

(c)

C1- C4

(d)

C1- C6

20. Lactose on hydrolysis gives

(a)

two molecules of glucose

(b)

glucose and fructose

(c)

two molecules of fructose

(d)

glucose and galactose