Anatomy Of Flowering Plants Question 69
Question: Most distinct annual rings are formed in:
Options:
A) Tropical region
B) Temperate region
C) Arctic region
D) Equatorial region
Show Answer
Answer:
Correct Answer: B
Solution:
Secondary growth results in the formation of concentric layers of secondary xylem, which are called as ‘annual rings’ and represent a seasonal increase in xylem. The width of rings represents the growth rate, which is lower in unfavorable seasons (winter and autumn) and comparatively higher in spring and summer.
A clear demarcation of different seasons (dry and wet; hot and cold) in temperate zone favors the formation of distinct annual rings.
Since tropical zones exhibit almost same climate throughout the year, the trees make indistinct annual rings. So, the correct answer is ‘Temperate’