What is heartwood What is sapwood What is the most abundant tissu.pdf

What is heartwood? What is sapwood? What is the most abundant tissue in the three-year-old
stem? What are three contrasting differences in structure between the sunflower stem and the
TNia stem? What are two techniques that can be used to determine the age of a woody twig?
Solution
1. Heart wood is the dead and inner wood tissue produced by cork cambium. It is dark in colr
and is distinguished from sap wood by its color and texture.
Sapwood is the outermost living wood tissue. It is also produced by cambium but is composed of
different types of cells. It is lightin color. It is involved conduction of water and minerals from
roots to all parts of tree.
2. In a three year old stem, the secondary xylem and phloem are bundant than primary xylem and
phloem. These vascular tissues conspicuously appear as annual rings by which the age of the tree
is known.
3.
4.
The age of a woody twig can be determined by counting the number of groups of bud scale scars
on it and he the number of terminal bud scale scars present.SunflowerTiliaAnnualperennialherb
exhibits no secondary growthtree exhibits secondary growthVascular bundles form a ring. Xylem
lies inside the vascular bundles. Phloem lies outside and phloem fibers are tough. The center of
stem is filled with ground tissue known as pithOne year old stem exhibits no secondary growth
and contains a layer of xylem and two later meristems called vascular and cork cambium.
During second year growth 2 rings of xylem is observed. During third year secondary xylem is
obseved and secondary phloem towards inside to xylem..

1. What is heartwood? What is sapwood? What is the most abundant tissue in the three-year-old
stem? What are three contrasting differences in structure between the sunflower stem and the
TNia stem? What are two techniques that can be used to determine the age of a woody twig?

Solution

1. Heart wood is the dead and inner wood tissue produced by cork cambium. It is dark in colr
and is distinguished from sap wood by its color and texture.
Sapwood is the outermost living wood tissue. It is also produced by cambium but is composed of
different types of cells. It is lightin color. It is involved conduction of water and minerals from
roots to all parts of tree.
2. In a three year old stem, the secondary xylem and phloem are bundant than primary xylem and
phloem. These vascular tissues conspicuously appear as annual rings by which the age of the tree
is known.
3.
4.
The age of a woody twig can be determined by counting the number of groups of bud scale scars
on it and he the number of terminal bud scale scars present.SunflowerTiliaAnnualperennialherb
exhibits no secondary growthtree exhibits secondary growthVascular bundles form a ring. Xylem
lies inside the vascular bundles. Phloem lies outside and phloem fibers are tough. The center of
stem is filled with ground tissue known as pithOne year old stem exhibits no secondary growth
and contains a layer of xylem and two later meristems called vascular and cork cambium.
During second year growth 2 rings of xylem is observed. During third year secondary xylem is
obseved and secondary phloem towards inside to xylem.