Photosynthesis

Question 1

What is the primary function of photosynthesis?

Answer 1

To convert light energy into chemical energy in the form of glucose.

Question 2

Which organisms primarily perform photosynthesis?

Answer 2

Plants, algae, and some bacteria.

Question 3

What is the main pigment involved in photosynthesis?

Answer 3

Chlorophyll.

Question 4

In which part of the plant does photosynthesis primarily occur?

Answer 4

In the leaves.

Question 5

What are the two main stages of photosynthesis?

Answer 5

Light-dependent reactions and light-independent reactions (Calvin cycle).

Question 6

True or False: Photosynthesis occurs only in the presence of sunlight.

Answer 6

True.

Question 7

What is the chemical equation for photosynthesis?

Answer 7

6CO2 + 6H2O + light energy → C6H12O6 + 6O2.

Question 8

What is produced as a byproduct of photosynthesis?

Answer 8

Oxygen.

Question 9

Where do the light-dependent reactions take place?

Answer 9

In the thylakoid membranes of the chloroplasts.

Question 10

What is the role of water in photosynthesis?

Answer 10

Water is split to provide electrons and protons, releasing oxygen.

Question 11

Fill in the blank: The light-independent reactions are also known as the _____ cycle.

Answer 11

Calvin.

Question 12

What are the products of the light-dependent reactions?

Answer 12

ATP, NADPH, and oxygen.

Question 13

Which molecule acts as an electron carrier in photosynthesis?

Answer 13

NADP+.

Question 14

What is the primary energy source for photosynthesis?

Answer 14

Sunlight.

Question 15

True or False: The Calvin cycle requires light directly.

Answer 15

False.

Question 16

What is the initial carbon source for the Calvin cycle?

Answer 16

Carbon dioxide (CO2).

Question 17

Which enzyme is crucial for fixing carbon dioxide in the Calvin cycle?

Answer 17

Ribulose bisphosphate carboxylase/oxygenase (RuBisCO).

Question 18

What is the significance of chloroplasts in photosynthesis?

Answer 18

Chloroplasts are the organelles where photosynthesis occurs.

Question 19

What are the two types of chlorophyll found in plants?

Answer 19

Chlorophyll a and chlorophyll b.

Question 20

Fill in the blank: The _____ captures light energy during photosynthesis.

Answer 20

chlorophyll.

Question 21

What is photolysis?

Answer 21

The process of splitting water molecules using light energy.

Question 22

Which gas is absorbed by plants during photosynthesis?

Answer 22

Carbon dioxide (CO2).

Question 23

What role do accessory pigments play in photosynthesis?

Answer 23

They capture additional light wavelengths and transfer energy to chlorophyll.

Question 24

How does temperature affect the rate of photosynthesis?

Answer 24

Increased temperature generally increases the rate up to a certain point before it denatures enzymes.

Question 25

What is the effect of light intensity on photosynthesis?

Answer 25

Higher light intensity increases the rate of photosynthesis until a saturation point is reached.

Question 26

What is the role of ATP in photosynthesis?

Answer 26

ATP provides energy for the Calvin cycle.

Question 27

True or False: The oxygen produced in photosynthesis comes from carbon dioxide.

Answer 27

False.

Question 28

What is the main carbohydrate produced during photosynthesis?

Answer 28

Glucose.

Question 29

Fill in the blank: The _____ is the liquid surrounding the thylakoids in chloroplasts.

Answer 29

stroma.

Question 30

What is the purpose of the light-dependent reactions?

Answer 30

To convert solar energy into chemical energy (ATP and NADPH).

Question 31

What happens to the products of the light-dependent reactions?

Answer 31

They are used in the Calvin cycle to produce glucose.

Question 32

Which phase of photosynthesis directly requires sunlight?

Answer 32

Light-dependent reactions.

Question 33

What is the main role of the thylakoid membrane?

Answer 33

To house the components necessary for the light-dependent reactions.

Question 34

What do plants do with excess glucose produced during photosynthesis?

Answer 34

They can store it as starch.

Question 35

Fill in the blank: The _____ cycle is essential for the regeneration of ribulose bisphosphate (RuBP).

Answer 35

Calvin.

Question 36

Which part of the chloroplast contains chlorophyll?

Answer 36

Thylakoids.

Question 37

What is the role of RuBP in the Calvin cycle?

Answer 37

RuBP combines with CO2 to initiate the cycle.

Question 38

How does carbon dioxide enter the leaf?

Answer 38

Through stomata.

Question 39

What happens to the rate of photosynthesis when carbon dioxide levels increase?

Answer 39

The rate of photosynthesis increases until it reaches a saturation point.

Question 40

True or False: All wavelengths of light are equally effective for photosynthesis.

Answer 40

False.

Question 41

What is the main factor limiting photosynthesis in low light conditions?

Answer 41

Insufficient light intensity.

Question 42

What is the significance of the light-independent reactions?

Answer 42

They synthesize glucose using ATP and NADPH from the light-dependent reactions.

Question 43

Fill in the blank: The enzyme _____ is crucial for the conversion of carbon dioxide to glucose.

Answer 43

RuBisCO.

Question 44

What is the role of NADPH in photosynthesis?

Answer 44

NADPH provides reducing power for the Calvin cycle.

Question 45

Which process do plants use to store energy in the form of glucose?

Answer 45

Photosynthesis.

Question 46

What is the main product of the Calvin cycle?

Answer 46

G3P (glyceraldehyde-3-phosphate).

Question 47

Fill in the blank: The _____ is the site of the Calvin cycle in the chloroplast.

Answer 47

stroma.

Question 48

What happens to the G3P produced in the Calvin cycle?

Answer 48

It can be used to form glucose and other carbohydrates.

Question 49

Which environmental factor can reduce the rate of photosynthesis during hot weather?

Answer 49

Water availability.

Question 50

What is the relationship between photosynthesis and cellular respiration?

Answer 50

Photosynthesis produces glucose and oxygen, while cellular respiration uses them to produce energy.

Question 51

Fill in the blank: In the Calvin cycle, carbon fixation occurs when CO2 is attached to _____.

Answer 51

RuBP.

Question 52

What is photophosphorylation?

Answer 52

The process of generating ATP from ADP and inorganic phosphate using light energy.

Question 53

What is the role of the stroma in chloroplasts?

Answer 53

It is the site of the light-independent reactions (Calvin cycle).

Question 54

Fill in the blank: _____ is the first stable product formed in the Calvin cycle.

Answer 54

3-PGA (3-phosphoglycerate).

Question 55

What are the main inputs for the light-dependent reactions?

Answer 55

Light energy, water, and ADP/NADP+.

Question 56

Which two products of photosynthesis are essential for cellular respiration?

Answer 56

Glucose and oxygen.

Question 57

Fill in the blank: The _____ hypothesis explains how chlorophyll absorbs light.

Answer 57

resonance.

Question 58

What is the purpose of the light-harvesting complexes in photosynthesis?

Answer 58

To capture and funnel light energy to the reaction center.

Question 59

Which factor can lead to photorespiration, reducing photosynthesis efficiency?

Answer 59

High oxygen concentration.

Question 60

Fill in the blank: The enzyme _____ is responsible for the fixation of carbon dioxide in the Calvin cycle.

Answer 60

RuBisCO.

Question 61

What is the effect of increased temperature on the enzymes involved in photosynthesis?

Answer 61

Increased temperature can enhance enzyme activity up to an optimal point, beyond which enzymes may denature.

Question 62

What is the role of chloroplasts in plant cells?

Answer 62

To carry out photosynthesis.

Question 63

Fill in the blank: The light-dependent reactions produce _____ and NADPH.

Answer 63

ATP.

Question 64

What is the primary role of the electron transport chain in photosynthesis?

Answer 64

To transfer electrons and create a proton gradient for ATP production.

Question 65

Which type of photosynthesis occurs in plants that grow in hot, dry environments?

Answer 65

C4 photosynthesis.

Question 66

Fill in the blank: The _____ cycle is also known as the dark reactions.

Answer 66

Calvin.

Question 67

What is the role of the guard cells in leaves?

Answer 67

To regulate the opening and closing of stomata.

Question 68

True or False: All plants are capable of performing photosynthesis.

Answer 68

False.

Question 69

What is the main difference between C3 and C4 photosynthesis?

Answer 69

C4 plants have an additional step to fix CO2 and can efficiently photosynthesize in low CO2 conditions.

Question 70

Fill in the blank: The _____ is responsible for capturing light energy during photosynthesis.

Answer 70

chlorophyll.

Question 71

What is the primary source of carbon for photosynthesis?

Answer 71

Atmospheric carbon dioxide (CO2).

Question 72

What is the role of the ATP synthase enzyme in photosynthesis?

Answer 72

To synthesize ATP from ADP and inorganic phosphate using a proton gradient.

Question 73

Fill in the blank: The _____ is a series of proteins in the thylakoid membrane that transfer electrons.

Answer 73

electron transport chain.

Question 74

What happens to the energy captured during the light-dependent reactions?

Answer 74

It is stored in ATP and NADPH for use in the Calvin cycle.

Question 75

Fill in the blank: The _____ produces glucose as a final product of photosynthesis.

Answer 75

Calvin cycle.

Question 76

What is the main function of stomata in photosynthesis?

Answer 76

To allow gas exchange (CO2 in, O2 out).

Question 77

What is the effect of high temperatures on photosynthesis?

Answer 77

It can lead to increased rates of photorespiration, reducing efficiency.

Question 78

Fill in the blank: _____ is the process of converting light energy into chemical energy.

Answer 78

Photosynthesis.

Question 79

What is the significance of the proton gradient in photosynthesis?

Answer 79

It drives ATP synthesis during the light-dependent reactions.

Question 80

Fill in the blank: The _____ is the fluid-filled space in chloroplasts where the Calvin cycle occurs.

Answer 80

stroma.

Question 81

What molecule is regenerated at the end of the Calvin cycle?

Answer 81

Ribulose bisphosphate (RuBP).

Question 82

Fill in the blank: The _____ is a key enzyme in the light-independent reactions.

Answer 82

RuBisCO.

Question 83

What is the effect of light wavelength on photosynthesis?

Answer 83

Different wavelengths of light are absorbed differently; red and blue light are most effective.

Question 84

Fill in the blank: The _____ is the part of the chloroplast that contains chlorophyll.

Answer 84

thylakoid.

Question 85

What is the primary purpose of the light reactions?

Answer 85

To convert solar energy into chemical energy in the form of ATP and NADPH.

Question 86

Fill in the blank: The light-dependent reactions require _____ to proceed.

Answer 86

light.

Question 87

What is the main product of the light-dependent reactions?

Answer 87

ATP and NADPH.

Question 88

Fill in the blank: The _____ cycle uses ATP and NADPH from the light-dependent reactions.

Answer 88

Calvin.

Question 89

What is the significance of chlorophyll a and b?

Answer 89

They absorb light at different wavelengths, optimizing energy capture.

Question 90

Fill in the blank: The _____ cycle occurs in the stroma of chloroplasts.

Answer 90

Calvin.

Question 91

Which molecule is the final product of the Calvin cycle that can be used to form glucose?

Answer 91

G3P (glyceraldehyde-3-phosphate).