Question

Amount of secondary xylem is more than secondary phloem because

• A. Cambium is more active on the outer side
• B. Cambium is more active on inner side
• C. Cambium has no rule
• D. Cambium is active equally on both sides but xylem is required

Answer 1

Answer: (B)

Cambium is more active on inner side

In the dicot stem, during intra stelar secondary growth, two types of cambia are formed. A strip of cambium formed between the xylem and phloem of a vascular bundle is called Intra fascicular cambium. Another strip of cambium is formed between vascular bundles by dedifferentiation of parenchyma present in the medullary rays is called Interfascicular cambium. Both intra and interfascicular cambia join together and form into a ring of cambium called vascular cambium. The activity of vascular cambium is influenced by maximum seasonal variations. Vascular cambium produces secondary xylem towards its inner side and secondary phloem towards its outer side. Due to this, more amount of secondary xylem is formed than secondary phloem.

So, the correct option is ‘Cambium is more active on the inner side’.