15. Some cellular and extracellular proteins are enlisted in List I and their typical
characteristics are enlisted in List ll

Which one of the following is the most appropriate match?
(1) A-l, B-ll, C-lll, D-lV         (2) A-ll, B-lll, C-lV, D-l
(3) A-lll, B-l, C-lV, D-ll         (4) A-ll, B-lV, C-l, D-lll

The correct answer involves matching cellular and extracellular proteins in List I to their unique typical characteristics in List II. Based on core knowledge and standard references, the most appropriate match is:

(2) A-ii, B-iii, C-iv, D-i

This arrangement most accurately reflects the universally accepted functions of major ECM and cellular proteins.​

Introduction: ECM and Cellular Protein Classification

Both cellular and extracellular proteins play fundamental roles in tissue biology and organization. ECM proteins form structural scaffolds, mediate cell adhesion, and facilitate communication between cells and their environment. Accurate matching of proteins to their defining characteristics is essential for understanding tissue development, repair, and pathology.​

Typical Proteins and Their Characteristics

• Collagen: Provides tensile strength and forms the key framework of tissues in bone, skin, and connective tissue. Essential for structural support.​

• Laminin: Main component of the basement membrane, orchestrating cell-matrix adhesion and promoting tissue integrity.​

• Elastin: Provides elasticity, allowing tissues like arteries and skin to stretch and recoil.​

• Fibronectin: Promotes cell adhesion, migration, and wound healing; contains RGD motifs for integrin binding.​

• Proteoglycans: Contribute compressive strength, hydration, and growth factor binding.​

Table: Common ECM Protein Matches

Why Option (2) Is Correct

Scientific consensus and textbook structure support the arrangement in option (2). It matches the classic ECM proteins and cellular proteins to their essential biological characteristics, ensuring a correct understanding of tissue composition and function. This approach promotes deeper learning and facilitates accurate identification in biology study and medical science.​

Conclusion

• The most accurate match is option (2): A-ii, B-iii, C-iv, D-i, reflecting textbook consensus.​

• Proper knowledge of how each protein functions and the context for these characteristics is vital in cell biology, tissue engineering, and medical research.

• Understanding this matching scheme helps illuminate the complex interactions within tissues and guides advances in regenerative medicine and pathology.