Which tissue provides mechanical support and flexibility to the growing parts of a plant?
A. Collenchyma
B. Sclerenchyma
C. Xylem
D. Parenchyma
Answer: Option A
Solution (By JKSSB Mock Tests)
Collenchyma is a simple permanent tissue characterized by cells with thickened corners due to the deposition of cellulose and pectin. It provides mechanical support, tensile strength, and flexibility to the growing parts of the plant (like stems and petioles), allowing them to bend without breaking. Parenchyma is for storage, and sclerenchyma provides rigid support.
Explanation:
Filippo Pacini first observed Vibrio cholerae in 1854, but Robert Koch later independently identified it and demonstrated its role. Koch is often credited, but Pacini's discovery was earlier. John Snow linked cholera to water.
Explanation:
Rhizobium species form symbiotic root nodules in legumes and fix atmospheric nitrogen into ammonia. Azotobacter is free-living, Nitrosomonas nitrifies, Lactobacillus ferments.
No comments yet. Be the first to start the discussion!