In plant anatomy, the 'Periderm' is a secondary protective tissue that replaces the epidermis in stems and roots undergoing secondary growth. It consists of three main layers: the phellem, phellogen, and phelloderm. The 'phellem' is also known as: MCQ with Answer and Explanation
In plant anatomy, the 'Periderm' is a secondary protective tissue that replaces the epidermis in stems and roots undergoing secondary growth. It consists of three main layers: the phellem, phellogen, and phelloderm. The 'phellem' is also known as:
A. Vascular cambium
B. Secondary cortex
C. Cork cambium
D. Cork
Answer: Option D
Solution (By JKExamLibrary)
The periderm is the outer protective covering of stems and roots that have undergone secondary growth (thickening), replacing the primary epidermis. It is composed of three distinct layers: 1) Phellem (cork): The outermost layer, consisting of dead, compactly arranged cells with suberized (waterproof) walls that provide protection and prevent water loss. 2) Phellogen (cork cambium): The middle, meristematic layer that produces phellem outwards and phelloderm inwards. 3) Phelloderm (secondary cortex): The innermost layer, consisting of living, parenchymatous cells.
Consider the following statements about the plant root:
1. Root hairs increase absorption surface area.
2. The root cap protects the root tip.
3. The zone of elongation is responsible for root growth in length.
Which of the above is/are correct?
Explanation:
Hemoglobin in red blood cells binds oxygen in the lungs and releases it in tissues. Each hemoglobin molecule can bind four O₂ molecules. It also carries some CO₂.
Explanation:
Folic acid prevents neural tube defects like spina bifida. It is recommended during early pregnancy. B₁₂ is for DNA synthesis, D for bone, K for clotting.
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