FORESTRY
PLANT AND WOOD ANATOMY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Uniform environmental conditions
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Non-uniform environmental conditions
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Absence of secondary growth
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Absence of primary growth
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Detailed explanation-1: -Annual rings are made out of a year’s worth of spring and fall wood. Annual rings are formed in trees due to non-uniform climatic conditions throughout the year. Cambium is very active in the spring season but in winter the activity reduces.
Detailed explanation-2: -Annual rings and growth rings are formed due to fluctuation in the activity of cambium. Cambium is the meristematic layer responsible for cutting off vascular tissues – xylem and phloem. Initially, it is present in patches as a single layer between vascular bundles.
Detailed explanation-3: -As annual rings require sharp climatic variations that are not available in the tropical, arctic or grassland regions so they are now present in the plants over there.
Detailed explanation-4: -Annual rings are bands of secondary xylem and xylem rays. Sometimes drought conditions prevail during the middle of a growing season resulting in formation of more than one annual ring. These are called as pseudo annual rings.