Biomass Energy Multiple Choice Questions on “Photosynthesis Process”.
1. What is photosynthesis?
a) Plants generating carbohydrates and oxygen from carbon dioxide, water and sunlight using chlorophyll
b) Algae generating carbohydrates and oxygen from carbon dioxide, water and sunlight using chlorophyll
c) Cyanobacteria generating carbohydrates and oxygen from carbon dioxide, water and sunlight using chlorophyll
d) Photoautotroph generating carbohydrates and oxygen from carbon dioxide, water and sunlight
Answer: d
Clarification: Photosynthesis is the process by which photoautotrophs generate food for themselves. They use carbon dioxide, water and sunlight to generate carbohydrates and oxygen. Photo means light.
2. What is the primary product of photosynthesis?
a) Glucose
b) Oxygen
c) Water
d) Carbon dioxide
Answer: a
Clarification: The primary product of photosynthesis is glucose. Oxygen is the by product. Water and carbon dioxide are the reactants.
3. Which of the following best indicates photosynthesis?
a) Carbon dioxide + water → oxygen + glucose
b) 6CO2 + 6H2O → C6H12O6 + 6O2 (in the presence of sunlight)
c) Carbon dioxide + water → glucose + oxygen (in the presence of sunlight)
d) Oxygen + glucose → carbon dioxide + water
Answer: b
Clarification: Photosynthesis occurs in the presence of sunlight. The balanced reaction of photosynthesis best describes the process of photosynthesis. The option with oxygen and glucose as reactants is not photosynthesis.
4. Which of the following organisms can perform photosynthesis?
a) Autotrophs
b) Algae
c) Photoautotrophs
d) Plants
Answer: c
Clarification: Photoautotrophs are organisms that perform photosynthesis to produce food for themselves. Algae and plants come under the category of photoautotrophs. All autotrophs are not necessarily photoautotrophs.
5. Which of the following are photoautotrophs?
a) Cyanobacteria, algae, plants
b) Archaebacteria
c) Deer
d) Tiger
Answer: a
Clarification: Cyanobacteria, algae and plants are photoautotrophs. Archaebacteria are chemoautotrophs. Deer and tiger are not autotrophs as they do not create their own food.
6. Conversion of usable sunlight energy into chemical energy is associated with _______
a) Red pigmentation
b) Green pigmentation
c) Orange pigmentation
d) Fruits
Answer: b
Clarification: Conversion of usable sunlight energy into chemical energy is associated with green pigmentation. This green pigmentation is called chlorophyll. Plants and algae consist of chlorophyll which is a key ingredient for photosynthesis.
7. Cyanobacteria have chloroplasts.
a) True
b) False
Answer: b
Clarification: Though cyanobacteria are photoautotrophs, they do not have chloroplasts. Instead, the chlorophyll is stored in thylakoids in their cytoplasm.
8. _______ and _______ is present in all chlorophylls.
a) A hydrophilic tail, a lipid soluble head
b) A hydrophobic tail, a lipid soluble head
c) A hydrophilic tail, a lipid insoluble head
d) A lipid soluble tail, a hydrophilic head
Answer: d
Clarification: A lipid soluble tail and a hydrophilic head is present in all chlorophylls. The tail is a lipid soluble hydrocarbon and the hydrophilic head consists of magnesium ion at its centre.
9. What type of chemical reactions are involved in photosynthesis?
a) Condensation reactions and redox reactions
b) Combustion
c) Double displacement
d) Single displacement
Answer: a
Clarification: The chemical reactions involved in photosynthesis are condensation reactions and redox reactions respectively. Combustion, single and double displacement reactions do not occur in photosynthesis.
10. What is the condensation reaction responsible for in the process of photosynthesis?
a) Electron transfer
b) Splitting out water molecules
c) Splitting out water molecules and phosphorylation
d) Electron transfer and phosphorylation
Answer: c
Clarification: Condensation reaction is responsible for splitting out water molecules and phosphorylation. Phosphorylation is the addition of a phosphate group to an organic compound. Electron transfer occurs in a redox reaction.
11. Where does the light-dependent reactions in the process of photosynthesis occur?
a) Stroma of chloroplasts
b) Thylakoid of chloroplasts
c) Inner membranes
d) Grana of chloroplasts
Answer: d
Clarification: The light-dependent reactions in the process of photosynthesis occur in the grana of chloroplasts. These reactions require the light energy to make energy-carrier molecules that are used further.
12. Where does the light-independent reactions in the process of photosynthesis occur?
a) Stroma of chloroplasts
b) Thylakoid of chloroplasts
c) Outer membranes
d) Grana of chloroplasts
Answer: a
Clarification: The light-independent reactions in the process of photosynthesis occur in the stroma of chloroplasts. The products of light reaction are used to make carbohydrates from carbon dioxide.
13. What is photoionisation? Assume presence of sunlight.
a) Freeing of electron from the molecule to form a negatively charged chlorophyll ion
b) Freeing of photoexcited electron from the molecule to form a positively charged chlorophyll ion
c) Absorbing of electron from the molecule to form a negatively charged chlorophyll ion
d) Absorbing of electron from the molecule to form a positively charged chlorophyll ion
Answer: b
Clarification: Electrons of chlorophyll molecule gain energy and move to higher energy level when light is absorbed. On gaining sufficiently high energy, the electron leaves the molecule thereby forming a positively charged chlorophyll ion. This process is called photoionisation.
14. Where does the energy to drive the electron transfer system come from?
a) Photosystem 1
b) Photosystem 3 and photosystem 2
c) Photosystem 1 and photosystem 2
d) Photosystem 1 and photosystem 3
Answer: c
Clarification: An electron transfer system (basically, a series of chemical reactions) carries two electrons to and fro across the thylakoid membrane. The energy for the system comes from photosystem 1 and photosystem 2.
15. Which of the following are products of light-dependent reactions?
a) ATP and glyceraldehyde 3-phosphate
b) Glyceraldehyde 3-phosphate and NADPH
c) Carbohydrates
d) ATP and NADPH
Answer: c
Clarification: The light-dependent reactions require direct energy of sunlight. They are a series of chemical reactions forming ATP and NADPH. These products are further used by light-independent reactions to produce carbohydrates.