1. Which pigment is primarily responsible for photosynthesis in algae?
A) Chlorophyll b
B) Chlorophyll a
C) Phycocyanin
D) Carotenoids
Answer: B) Chlorophyll a
2. Algae contribute to carbon fixation primarily through which process?
A) Chemosynthesis
B) Fermentation
C) Photosynthesis
D) Respiration
Answer: C) Photosynthesis
3. Algae are responsible for fixing approximately what percentage of the Earth’s carbon?
A) 10%
B) 20%
C) 30-50%
D) 70%
Answer: C) 30-50%
4. What type of algae is most efficient in carbon fixation?
A) Green algae
B) Red algae
C) Diatoms
D) Brown algae
Answer: C) Diatoms
5. In carbon fixation, algae convert CO2 into what compound during photosynthesis?
A) Oxygen
B) Carbohydrates
C) Proteins
D) Lipids
Answer: B) Carbohydrates
6. Which enzyme is essential for the carbon fixation process in algae?
A) ATP synthase
B) Rubisco
C) Hexokinase
D) Phosphatase
Answer: B) Rubisco
7. The carbon-concentrating mechanism (CCM) in algae helps to:
A) Increase oxygen uptake
B) Reduce photorespiration
C) Fix nitrogen
D) Store energy
Answer: B) Reduce photorespiration
8. Algae play a crucial role in carbon fixation in which environment?
A) Terrestrial ecosystems
B) Deep soil layers
C) Aquatic ecosystems
D) Mountain regions
Answer: C) Aquatic ecosystems
9. Diatoms store fixed carbon in the form of:
A) Glycogen
B) Starch
C) Lipids
D) Proteins
Answer: C) Lipids
10. Which form of carbon is absorbed by algae for fixation?
A) Carbon monoxide
B) Carbon dioxide
C) Carbonic acid
D) Bicarbonates
Answer: B) Carbon dioxide
11. Marine algae contribute to carbon fixation in the ocean through:
A) Bioluminescence
B) Primary production
C) Secondary production
D) Nitrogen fixation
Answer: B) Primary production
12. The ocean’s “biological pump” refers to:
A) Mixing of nutrients
B) Upwelling of water
C) Transfer of carbon to deep-sea sediments
D) Conversion of oxygen into carbon
Answer: C) Transfer of carbon to deep-sea sediments
13. Which group of algae is a significant contributor to the global carbon cycle?
A) Cyanobacteria
B) Dinoflagellates
C) Diatoms
D) All of the above
Answer: D) All of the above
14. The carbon fixation pathway in algae is known as:
A) Glycolysis
B) Calvin cycle
C) Krebs cycle
D) Beta-oxidation
Answer: B) Calvin cycle
15. Algae’s role in carbon fixation helps mitigate:
A) Acid rain
B) Climate change
C) Soil erosion
D) Habitat destruction
Answer: B) Climate change
16. Algae use carbon fixation to support which of the following?
A) Cell respiration
B) Growth and reproduction
C) Nitrogen release
D) Waste removal
Answer: B) Growth and reproduction
17. What is the primary habitat of algae that contributes to carbon fixation?
A) Deserts
B) Polar ice caps
C) Water bodies
D) Underground caves
Answer: C) Water bodies
18. Algae store excess fixed carbon in the form of:
A) Lipids and starch
B) Proteins and nucleic acids
C) Vitamins
D) Mineral deposits
Answer: A) Lipids and starch
19. Which algae are known for their role in carbon fixation and forming coral reefs?
A) Green algae
B) Zooxanthellae
C) Red algae
D) Brown algae
Answer: B) Zooxanthellae
20. Carbon fixation in algae occurs in which part of the cell?
A) Nucleus
B) Mitochondria
C) Chloroplast
D) Ribosome
Answer: C) Chloroplast
21. Which gas is released as a by-product of carbon fixation in algae?
A) Carbon dioxide
B) Oxygen
C) Methane
D) Nitrogen
Answer: B) Oxygen
22. Which of these algae is most abundant in the oceans?
A) Cyanobacteria
B) Spirogyra
C) Volvox
D) Laminaria
Answer: A) Cyanobacteria
23. The process of carbon fixation in algae reduces:
A) Atmospheric nitrogen levels
B) Ocean salinity
C) Global CO2 levels
D) Soil nutrient content
Answer: C) Global CO2 levels
24. Which nutrient is vital for the growth of algae in carbon fixation?
A) Sodium
B) Nitrogen
C) Sulfur
D) Potassium
Answer: B) Nitrogen
25. Algal blooms can affect carbon fixation by:
A) Decreasing oxygen production
B) Increasing CO2 absorption
C) Blocking sunlight
D) Increasing ocean acidity
Answer: C) Blocking sunlight
26. Which feature makes algae efficient in carbon fixation?
A) High metabolic rate
B) Simple cell structure
C) Large surface area
D) Presence of specialized pigments
Answer: D) Presence of specialized pigments
27. The study of algae’s role in carbon fixation is termed:
A) Mycology
B) Phycology
C) Limnology
D) Ecology
Answer: B) Phycology
28. Algae contribute to the formation of which fossil fuel?
A) Natural gas
B) Coal
C) Oil
D) Peat
Answer: C) Oil
29. How do algal mats impact carbon fixation?
A) They trap and store carbon
B) They release CO2 into the atmosphere
C) They prevent photosynthesis
D) They consume oxygen
Answer: A) They trap and store carbon
30. Algae can be genetically engineered to:
A) Produce more carbon dioxide
B) Enhance carbon fixation efficiency
C) Reduce chlorophyll levels
D) Destroy greenhouse gases
Answer: B) Enhance carbon fixation efficiency
