Older resin-clogged central secondary xylem and younger outer secondary xylem are respectively known as
Older resin-clogged central secondary xylem and younger outer secondary xylem are respectively known as
The correct option is B Duramen and alburnum
In dicotyledonous stems, during intra stellar secondary growth, a ring of cambium called vascular cambium is formed. In the plants growing temperate regions, the activity of vascular cambium is influenced by the existence of maximum seasonal variations. In the spring or early summer, due to the existence of favourable conditions, a large amount of secondary xylem is formed. it is called Springwood or early wood. In the autumn season, due to the presence of unfavourable conditions, less amount of wood is formed. it is called autumn wood or latewood. A spring wood and autumn wood together form into an annual ring. Every annual ring becomes sapwood, it is light coloured, peripheral functional wood and every sap wood gradually transform into heat wood, it is inner or central dark coloured non-functional wood contains resin clogged structures called tyloses.
So, the correct answer is 'Duramen and alburnum'.
In dicotyledonous stems, during intra stellar secondary growth, a ring of cambium called vascular cambium is formed. In the plants growing temperate regions, the activity of vascular cambium is influenced by the existence of maximum seasonal variations. In the spring or early summer, due to the existence of favourable conditions, a large amount of secondary xylem is formed. it is called Springwood or early wood. In the autumn season, due to the presence of unfavourable conditions, less amount of wood is formed. it is called autumn wood or latewood. A spring wood and autumn wood together form into an annual ring. Every annual ring becomes sapwood, it is light coloured, peripheral functional wood and every sap wood gradually transform into heat wood, it is inner or central dark coloured non-functional wood contains resin clogged structures called tyloses.
So, the correct answer is 'Duramen and alburnum'.
