Basic Biochemistry & Biomolecules

• Function of Amyloplasts: Amyloplasts are non-pigmented plastids (leucoplasts) specialized for the polymerization and long-term storage of starch (amylose and amylopectin) in nutrient storage organs such as roots, tubers (potatoes), and seed endosperms.
• Plastid Specializations: Proteinoplasts/aleuroplasts store proteins, while elaioplasts store lipids/oils. Amyloplasts in root columella cells also serve as statoliths for gravity perception (gravitropism).

Correct option: (2) Storage of starch

• Statement (I) is False: Chloroplasts are fully differentiated, highly active photosynthetic plastids; chromoplasts and gerontoplasts typically represent terminal, non-photosynthetic or degenerative plastid stages.
• Statement (II) is True: According to the Endosymbiotic Theory (Lynn Margulis), chloroplasts originated from ancestral photosynthetic cyanobacteria engulfed by early eukaryotic cells, retaining a circular genome, 70S ribosomes, and a double-membrane envelope.
• Conclusion: Statement (I) is false but Statement (II) is true.

Correct option: (4) Statement (I) is false but Statement ({I) is true.

• Definition of Isoschizomers: Restriction endonucleases that recognize the identical target nucleotide sequence.
• Hpall and Mspl: Both enzymes recognize the tetranucleotide palindromic sequence $5'\text{-CCGG-3'}$. They differ in methylation sensitivity: HpaII is inhibited if the internal cytosine is methylated ($5'\text{-C}^m\text{CGG-3'}$), whereas MspI cleaves whether the internal cytosine is methylated or unmethylated, making them indispensable tools for studying DNA methylation.
• Neoschizomers: Enzymes that recognize the same sequence but cleave at different positions.

Correct option: (2) Hpall and Mspl