chemistry MCQs - 10th class Chapter 05 Mcqs

1

Which of the following is defined as a polyhydroxy aldehyde or ketone?

A

Protein

B

Lipid

C

Carbohydrate

D

Nucleic Acid

2

Carbohydrates are synthesized by plants through which process?

A

Respiration

B

Photosynthesis

C

Transpiration

D

Decomposition

3

Monosaccharides are the simplest sugars that cannot be what?

A

Hydrolyzed

B

Synthesized

C

Polymerized

D

Dissolved

4

Glucose is an example of a?

A

Pentahydroxy aldehyde

B

Pentahydroxy ketone

C

Disaccharide

D

Polysaccharide

5

Which of the following is a characteristic of monosaccharides?

A

Insoluble in water

B

Sour taste

C

White crystalline solids

D

Non-reducing

6

Oligosaccharides give how many units of monosaccharides on hydrolysis?

A

1 to 2

B

2 to 9

C

10 to 20

D

Hundreds

7

Sucrose on hydrolysis produces one unit of glucose and one unit of what?

A

Galactose

B

Fructose

C

Maltose

D

Lactose

8

Which of the following is an example of a polysaccharide?

A

Glucose

B

Sucrose

C

Starch

D

Lactose

9

What is a key characteristic of polysaccharides?

A

Sweet taste

B

Soluble in water

C

Crystalline solids

D

Tasteless and insoluble in water

10

Which is the only form of carbohydrate used directly by muscles for energy?

A

Fructose

B

Sucrose

C

Glucose

D

Starch

11

The brain needs which carbohydrate as an energy source?

A

Fat

B

Fructose

C

Glucose

D

Sucrose

12

Dietary fibre helps in lowering of which level?

A

Blood sugar

B

Cholesterol

C

Blood pressure

D

Energy

13

One gram of carbohydrates provides how many kilojoules of energy?

A

10

B

17

C

25

D

30

14

Dextrose is another name for what?

A

Fructose

B

Crystallized glucose

C

Sucrose

D

Lactose

15

Proteins are polymers of what?

A

Fatty acids

B

Nucleotides

C

Amino acids

D

Monosaccharides

16

The linkage between amino acids in a protein is called?

A

Glycosidic bond

B

Ester linkage

C

Peptide linkage

D

Hydrogen bond

17

How many different amino acids are there?

A

10

B

20

C

30

D

50

18

Amino acids that cannot be synthesized by the human body are called what?

A

Non-essential

B

Basic

C

Essential

D

Acidic

19

What percentage of the dry weight of a cell is made up of proteins?

A

About 20%

B

About 30%

C

About 40%

D

About 50%

20

Enzymes, which catalyze chemical reactions in the body, are what type of molecule?

A

Carbohydrates

B

Lipids

C

Proteins

D

Nucleic Acids

21

Gelatin, used in bakery items, is obtained by heating what?

A

Hides

B

Muscles

C

Bones

D

Hair

22

Lipids are macromolecules made up of what?

A

Amino acids

B

Fatty acids

C

Monosaccharides

D

Nucleotides

23

Oils and fats are esters of long-chain carboxylic acids with what molecule?

A

Glucose

B

Glycerol

C

Amino acid

D

Phosphate

24

At room temperature, oils exist in what form?

A

Solid

B

Liquid

C

Gas

D

Semi-solid

25

Fats are triglycerides of which type of fatty acids?

A

Unsaturated

B

Polyunsaturated

C

Saturated

D

Monounsaturated

26

Which of the following is an example of a saturated fatty acid?

A

Oleic acid

B

Linoleic acid

C

Palmitic acid

D

Arachidonic acid

27

Fats stored in the body serve what function?

A

Conducting heat

B

Insulating the body

C

Dissolving in water

D

Regulating blood sugar

28

Hydrogenation of vegetable oil is carried out in the presence of which catalyst?

A

Iron

B

Platinum

C

Nickel

D

Zinc

29

Nucleic acids are long-chain molecules made up of what?

A

Amino acids

B

Fatty acids

C

Monosaccharides

D

Nucleotides

30

A nucleotide consists of a nitrogenous base, a phosphate group, and what else?

A

A hexose sugar

B

A pentose sugar

C

An amino acid

D

Glycerol

31

The double helix structure of DNA was discovered by whom?

A

Hopkins and Funk

B

Watson and Crick

C

Louis Pasteur

D

Robert Brown

32

What is the function of the sugar and phosphate groups in a DNA chain?

A

Linking the bases

B

Forming the backbone

C

Storing genetic code

D

Providing energy

33

What is the primary function of DNA?

A

Synthesizing proteins directly

B

Providing energy to the cell

C

Permanent storage of genetic information

D

Catalyzing reactions

34

RNA is responsible for directing the synthesis of new what?

A

Carbohydrates

B

Lipids

C

Proteins

D

Cells

35

In 1912, who noticed that substances other than carbohydrates, proteins, and fats are needed for normal growth?

A

Funk

B

Watson

C

Hopkins

D

Crick

36

Vitamins that dissolve in fat are known as?

A

Water soluble vitamins

B

Fat soluble vitamins

C

Essential vitamins

D

Non-essential vitamins

37

Which of the following is a fat-soluble vitamin?

A

Vitamin C

B

Vitamin B complex

C

Vitamin A

D

Vitamin B1

38

An accumulation of which vitamin in the body can cause bone-pain?

A

Vitamin C

B

Vitamin B12

C

Vitamin D

D

Vitamin B6

39

A deficiency of Vitamin A can cause what condition?

A

Rickets

B

Scurvy

C

Night blindness

D

Anaemia

40

Rickets is caused by the deficiency of which vitamin?

A

Vitamin A

B

Vitamin C

C

Vitamin K

D

Vitamin D

41

Which vitamins are rapidly excreted from the body and are not toxic in large quantities?

A

Fat soluble

B

Water soluble

C

Vitamins A and D

D

Vitamins E and K

42

What is the role of enzymes like lipases and amylases in detergents?

A

To add fragrance

B

To soften fabrics

C

To remove stains

D

To colour the water

43

Lactase enzyme is used in the dairy industry to increase sweetness in what product?

A

Cheese

B

Yogurt

C

Butter

D

Ice cream

44

Denaturing of protein can be carried out by?

A

Cooling

B

Dissolving in water

C

Heating or changing pH

D

Adding sugar

45

Cotton is an example of pure?

A

Starch

B

Cellulose

C

Protein

D

Lipid

46

The main sugar in milk and dairy products is?

A

Sucrose

B

Maltose

C

Lactose

D

Fructose

47

Maltose is a disaccharide made of two molecules of what?

A

Fructose

B

Galactose

C

Glucose

D

Sucrose

48

Which macromolecules are responsible for transmitting genetic information from generation to generation?

A

Proteins

B

Carbohydrates

C

Lipids

D

Nucleic acids

49

Which substance is used to make leather by tanning?

A

Gelatin

B

Hides

C

Bones

D

Fats

50

The general formula of carbohydrates is?

A

$C_{n}(H_{2}O)_{2n}$

B

$C_{n}(H_{2}O)_{n}$

C

$C_{2n}(H_{2}O)_{n}$

D

$C_{n}(H_{2}O)$