The correct answer is (1) A, B, and C:

• (A) Chlorophylls a and b are abundant in green plants.

• (B) Chlorophylls c and d are found in some protists and cyanobacteria.

• (C) Of different types of bacteriochlorophyll, type a is the most widely distributed.

Statement D is incorrect—bacteriochlorophyll a, not b, is the most widely distributed in photosynthetic bacteria.

Chlorophyll Types and Distribution: Plant and Bacterial Pigments

Introduction

Key phrase: types and distribution of chlorophylls bacteriochlorophyll green plants cyanobacteria protists

Chlorophylls are the core pigments for light absorption and energy transfer in oxygenic and anoxygenic photosynthesis. Their different forms—chlorophylls a, b, c, d, and bacteriochlorophylls—are distributed according to organism type and ecological niche.

Explanation of Each Statement

• A. Chlorophylls a and b are abundant in green plants.

  • Correct. Chlorophyll a is present in all green plants, algae, and cyanobacteria. Chlorophyll b is also widespread in land plants and green algae.

• B. Chlorophylls c and d are found in some protists and cyanobacteria.

  • Correct. Chlorophyll c occurs in many algal protists such as dinoflagellates and diatoms, while chlorophyll d is found in certain cyanobacteria and red algae.

• C. Out of different types of bacteriochlorophyll, type a is the most widely distributed.

  • Correct. Bacteriochlorophyll a is found in numerous photosynthetic bacteria including purple and green bacteria and is more common than type b.

• D. Out of different types of bacteriochlorophyll, type b is the most widely distributed.

  • Incorrect. Bacteriochlorophyll b is less common; type a is the most prevalent in anoxygenic bacteria.

Key Facts: Chlorophyll and Bacteriochlorophyll Distribution

• Chlorophyll a: Universal in oxygenic photosynthesis.

• Chlorophyll b: Associated with green plants, land plants, and many algae.

• Chlorophyll c/d: Primarily in certain algae and cyanobacteria.

• Bacteriochlorophyll a: Most widely distributed among photosynthetic bacteria; b is less common.