Question

Which wood burns for a short period of time?
A) Gymnosperms
B) Angiosperm
C) Dicotyledons
D) Monocotyledons

Answer 1

Monocot does not show secondary growth as it lacks a cambium ring, so it does not form woods. On the other hand, coal is produced from dicotyledenous plants that show secondary growth.

Complete step by step answer: Due to secondary growth in dicot plants, several kinds of woods are formed and these are:

1. Springwood: We know that secondary growth occurs due to the cambial activity and its activity is not similar throughout the year. Like in the spring season, it is very active and produces a lot of xylem elements having wider cavities and the wood formed is called springwood or earlywood.
2. Autumn wood: During the autumn season, cambium is not very active, and hence, form very fewer xylem elements having narrower vessels, and the wood formed is called autumn or latewood.
3. Heartwood: It is present in the innermost or central area of the wood where there is deposition of tannin, resins, gums and oils. These things make this area hard and resistance to attack of insects and hence, these parts are often used for furniture making. This part donot conduct water, it only provides mechanical support to the plant.
4. Sapwood: These are present in the periphery of the wood, and they are mainly meant for the conduction of water from root to leaf. Gymnosperm produces firewood having wide calorific value and can provide a large amount of energy than coal.
   Hence, the correct answer is option C.

Note: Vascular bundle consists of xylem and phloem. In dicot plants, there is a cambium present between the xylem and phloem, which is responsible for secondary growth in them. This type of vascular bundle is called an open type of vascular bundle. While, in monocots, there is no such cambium ring in between the vascular bundle, this condition is called the closed type of vascular bundle.