Question

The cork cambium, cork and secondary cortex are collectively called

• A. phellem
• B. periderm
• C. phellogen
• D. phelloderm

Answer 1

The correct option is A

Explanation of the correct answer:

1. In woody plants, cork cambium is the outermost lateral meristem.
2. Cork cambium, also called phellogen, is another meristematic tissue developed in the cortex region.
3. Due to the cambial ring activity, the outer layers such as cortex cells and epidermis get crushed.
4. This is the time when the cork cambium develops as a new protective layer.
5. Cork cambium starts to differentiate cells and form outer cork (phellem) and inner secondary cortex (phelloderm).

Explanation of the incorrect answers:

Option B:

1. The cork cambium starts to differentiate cells and form outer cork which is called phellem.

2. But cork cambium(phellogen) + outer cork(phellem) + secondary cortex(phelloderm) = periderm.

Option C:

1. Cork cambium, also called phellogen, is another meristematic tissue developed in the cortex region.

2. But cork cambium(phellogen) + outer cork(phellem) + secondary cortex(phelloderm) = periderm.

Option D:

1. Cork cambium starts to differentiate cells and form inner secondary cortex (phelloderm).

2. But cork cambium(phellogen) + outer cork(phellem) + secondary cortex(phelloderm) = periderm.

Final answer: The cork cambium, cork and secondary cortex are collectively called periderm.