Q.There were two cut logs of wood lying in the campus. One had growth rings and other didn't. Teacher said it is due to differences in their pattern of growth which is dependent on season. How?

Step 1. A growth ring is not a single event but the visible record of one full seasonal cycle of cambial activity: broad, pale, low-density spring (early) wood laid down in favourable conditions, followed by narrow, dark, high-density autumn (late) wood laid down in unfavourable conditions.

Step 2. For a distinct ring to be visible, the transition between spring wood and autumn wood has to be sharp — which only happens where the growing season and the dormant/unfavourable season are clearly distinguishable, i.e. a genuinely seasonal climate.

Step 3. In a region without such seasonal contrast (a fairly uniform climate year-round), the cambium keeps dividing at roughly the same rate and produces roughly uniform wood continuously, so there is no sharp spring-to-autumn boundary to see as a ring. …

Link visible growth rings to the seasonal alternation of spring wood and autu …

• Thinking growth rings indicate the tree's age only, without explaining WHY a ring forms in the first place (the answer must explain the wood-type alternation, not just state that rings = age). …