biology MCQs - 9th class Chapter 08 Mcqs

1

What is the study of energy transformations in living organisms called?

A

Metabolism

B

Bioenergetics

C

Ecology

D

Genetics

2

Which molecule is considered the main energy-transfer molecule in the cell?

A

Glucose

B

NADPH

C

ATP

D

DNA

3

Who proposed that ATP is the main energy-transfer molecule in the cell in 1941?

A

Melvin Calvin

B

Sir Hans Krebs

C

Fritz Lipmann

D

Louis Pasteur

4

An ATP molecule consists of adenine, a ribose sugar, and how many phosphate groups?

A

One

B

Two

C

Three

D

Four

5

How much energy is released when one phosphate bond in ATP is broken?

A

7.3 kcal/mole

B

73 kcal/mole

C

730 kcal/mole

D

0.73 kcal/mole

6

The conversion of ATP to ADP is what type of process?

A

Energy-storing

B

Energy-releasing

C

Anabolic

D

Photosynthetic

7

Photosynthesis is the synthesis of glucose from carbon dioxide and what other reactant?

A

Oxygen

B

Nitrogen

C

Water

D

Hydrogen

8

Where do the light reactions of photosynthesis take place?

A

Stroma of chloroplasts

B

Thylakoid membranes of chloroplasts

C

Cytoplasm

D

Mitochondria

9

Where do the dark reactions (Calvin Cycle) of photosynthesis occur?

A

Thylakoid membranes of chloroplasts

B

Cytoplasm

C

Mitochondria

D

Stroma of chloroplasts

10

What are the high-energy molecules produced during light reactions?

A

ATP and Glucose

B

ATP and NADPH

C

Glucose and Oxygen

D

NADPH and CO2

11

During light reactions, what molecule is broken down to release oxygen?

A

Glucose

B

Carbon dioxide

C

Water

D

Chlorophyll

12

What is the primary function of dark reactions?

A

To produce ATP

B

To reduce carbon dioxide to make glucose

C

To release oxygen

D

To absorb sunlight

13

Who discovered the details of the dark reactions of photosynthesis?

A

Fritz Lipmann

B

Sir Hans Krebs

C

Melvin Calvin

D

Robert Hooke

14

In the Calvin cycle, CO2 combines with a 5-carbon compound to form an unstable intermediate of how many carbons?

A

3-carbon compound

B

4-carbon compound

C

6-carbon compound

D

7-carbon compound

15

What is the main pigment involved in photosynthesis?

A

Carotenoids

B

Chlorophyll-b

C

Xanthophyll

D

Chlorophyll-a

16

What colors of light does chlorophyll-a absorb most effectively?

A

Green and Yellow

B

Blue and Green

C

Red and Blue

D

Orange and Red

17

Substances that absorb visible light are known as?

A

Enzymes

B

Pigments

C

Hormones

D

Substrates

18

The oxidation of food to release energy inside cells is called what?

A

Photosynthesis

B

Digestion

C

Cellular respiration

D

Transpiration

19

What is the most common food used by cells for energy through respiration?

A

Fructose

B

Sucrose

C

Glucose

D

Lactose

20

Cellular respiration that occurs in the presence of oxygen is called?

A

Anaerobic respiration

B

Fermentation

C

Aerobic respiration

D

Glycolysis

21

What is the first phase of both aerobic and anaerobic respiration?

A

Krebs cycle

B

Electron transport chain

C

Glycolysis

D

Calvin cycle

22

In glycolysis, one molecule of glucose is broken down into two molecules of what?

A

Lactic acid

B

Acetyl-CoA

C

Pyruvic acid

D

Ethanol

23

Cellular respiration occurring in the absence of oxygen is known as?

A

Aerobic respiration

B

Photosynthesis

C

Anaerobic respiration

D

Krebs cycle

24

In alcoholic fermentation, pyruvic acid is broken down into ethanol and what other substance?

A

Oxygen

B

Water

C

Lactic acid

D

Carbon dioxide

25

Which type of fermentation occurs in the skeletal muscles of humans during intense exercise?

A

Alcoholic fermentation

B

Lactic acid fermentation

C

Acetic acid fermentation

D

Propionic fermentation

26

Which organisms are mentioned as being capable of making birds drunk from eating fermented berries?

A

Bacteria

B

Yeast

C

Fungi

D

Algae

27

The use of fermentation in yeast is important for which industries?

A

Dairy and Plastic

B

Brewing and Baking

C

Textile and Paper

D

Pharmaceutical and Fuel

28

Where does glycolysis occur in the cell?

A

Mitochondria matrix

B

Inner mitochondrial membrane

C

Chloroplast

D

Cytoplasm

29

After glycolysis, if oxygen is available, pyruvic acid moves into the?

A

Cytoplasm

B

Nucleus

C

Matrix of mitochondria

D

Ribosomes

30

The Krebs cycle was discovered by which British scientist?

A

Melvin Calvin

B

Fritz Lipmann

C

Sir Hans Krebs

D

Alexander Fleming

31

In the Krebs cycle, acetyl coenzyme-A is completely oxidized to what molecule?

A

Oxygen

B

Water

C

Carbon dioxide

D

Glucose

32

What are the energy-rich compounds produced during the Krebs cycle besides ATP?

A

NADH and FADH2

B

NADPH and FAD

C

Glucose and Oxygen

D

CO2 and H2O

33

Where does the electron transport chain occur in the mitochondria?

A

Outer membrane

B

Matrix

C

Inner membrane

D

Intermembrane space

34

In the electron transport chain, the energy from electrons is used to make what?

A

Glucose

B

ATP

C

NADH

D

Water

35

What is the final electron acceptor at the end of the electron transport chain?

A

Nitrogen

B

Carbon

C

Oxygen

D

Sulphur

36

What is the net profit of ATP molecules from one glucose molecule during anaerobic respiration?

A

36

B

12

C

4

D

2

37

What are the final products of aerobic respiration?

A

Lactic acid

B

Ethanol and CO2

C

CO2 and H2O

D

Glucose and Oxygen

38

Photosynthesis is what type of metabolic process?

A

Catabolic

B

Anabolic

C

Amphibolic

D

Exergonic

39

Cellular respiration is what type of metabolic process?

A

Anabolic

B

Endergonic

C

Catabolic

D

Photosynthetic

40

Photosynthesis occurs in which organelle?

A

Mitochondria

B

Ribosomes

C

Chloroplasts

D

Nucleus

41

Cellular respiration primarily occurs in the cytoplasm and which other organelle?

A

Chloroplasts

B

Mitochondria

C

Vacuole

D

Endoplasmic Reticulum

42

During which time does photosynthesis primarily occur?

A

All the time

B

In daytime only

C

In nighttime only

D

During dawn and dusk

43

In what form is energy invested in photosynthesis?

A

Chemical bond energy

B

Heat energy

C

Light energy

D

Kinetic energy

44

The breakdown of pyruvic acid into acetyl coenzyme-A releases NADH and what else?

A

Oxygen

B

Water

C

Carbon dioxide

D

ATP

45

What process results in the formation of two ATPs and two NADH from one glucose molecule?

A

Krebs Cycle

B

Electron Transport Chain

C

Fermentation

D

Glycolysis

46

How many net ATP molecules are produced in aerobic respiration from one glucose molecule?

A

2

B

4

C

18

D

36

47

What is the role of accessory pigments like chlorophyll-b and carotenoids?

A

Absorb the main light wavelengths

B

Absorb wavelengths not absorbed by chlorophyll-a

C

Reflect all light

D

Produce oxygen

48

The process where a molecule gains electrons is called?

A

Oxidation

B

Reduction

C

Hydrolysis

D

Phosphorylation

49

The process where a molecule loses electrons is called?

A

Reduction

B

Oxidation

C

Condensation

D

Fermentation

50

What is the byproduct of lactic acid fermentation?

A

Ethanol

B

CO2

C

Water

D

Lactic acid