Question

Choose the correct statements among the following
A) By the deposition of the organic compounds the heartwood is resistance to attacking of Insects
B) Growth ring is produced with the activity of autumn wood
C) The function of phellogen is to provide protection layer to the broken parts of outer cortical and epidermal layers, in the secondary growth of vascular cambium

• A. A, B, C
• B. Both A & B
• C. Both B & C
• D. Both A & C

Hint:

One annual ring = One spring wood band + One autumn wood band.
They represent the seasonal environmental variations in vascular cambium activity over one year.

Answer 1

The Correct Option is D

Step 1: Confirm the heartwood statement.
As secondary xylem ages near the centre of a trunk, it stops conducting water and instead fills up with tannins, resins, oils and gums, this deposition is exactly what makes heartwood dark, durable and resistant to insect or fungal attack, so statement A is correct.
Step 2: Confirm the phellogen statement.
During secondary growth the cork cambium, or phellogen, produces new protective tissue that replaces the outer cortex and epidermis once they get stretched and broken by the expanding girth, so statement C is correct too.
Step 3: Check the growth ring statement.
A growth ring is not produced by autumn wood alone, it is the visible boundary formed because spring wood, with larger vessels and lighter colour, and autumn wood, with smaller vessels and denser colour, are laid down together in a yearly cycle, so crediting autumn wood alone makes statement B incorrect.
Final answer: Option 4, statements A and C are correct while B is false.