Question

39. Why are annual rings formed in the flowering plants of temperate regions?
40. Define periderm​

Answer 1

Answer:

Answer of 39 question-Growth rings are formed by the seasonal activity of cambium. In plants of temperate regions, cambium is more active in spring and less active in autumn seasons. In temperate regions climatic conditions are not uniform throughout the year. However in tropics climatic conditions are uniform throughout the year.

Answer of 40 question-an outer layer of tissue especially : a cortical protective layer of many roots and stems that typically consists of phellem, phellogen, and phelloderm.

Explanation:

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Answer 2

Ans 39.Growth rings are formed by the seasonal activity of cambium. In plants of temperate regions, cambium is more active in spring and less active in autumn seasons. In temperate regions climatic conditions are not uniform throughout the year. However in tropics climatic conditions are uniform throughout the year.

40.Periderm is a component of secondary growth that is formed towards the surface of stems and roots, having phellem, phellogen and phelloderm.