BLOSUM matrix is used for
BLOSUM matrix is used for
Select an option to attempt
Correct Answer: Option D
Explanation
Virus-free plant propagation exploits the fact that apical meristematic cells at the shoot apex divide rapidly and typically remain free from systemic viral infection because: (1) Viruses spread through the vascular system (phloem), which is not yet established in newly dividing meristematic cells; (2) The apical dome (the distal 0.1–0.5 mm, containing the true meristem) lacks vascular connections; (3) Cell division rate may outpace viral spread. Very small meristem tips (0.1–0.3 mm, with only 1–2 leaf primordia) excised under sterile conditions and cultured on appropriate media produce virus-free plants. Combined with thermotherapy (37°C treatment) or chemotherapy (antiviral ribavirin), success rates are further improved.