What are the constituent of phloem

Hint: Vascular plants have vascular bundles which help in the transportation of various substances. There are two types of vascular bundles found in plants - Xylem and Phloem. Complete answer: Phloem is basically a living tissues which helps in conduction of soluble organic compounds which are produced during the process of photosynthesis downwards from leaves, The components of phloem are: - >Sieve element :They are long tubular structures and are placed one above the other forming a sieve tube. They lack a nucleus. Sometimes they have a special type of thickening called nacreous thickening. Sieve tubes are syncytes i.e. formed by fusion of cells. >Companion cell:They are living, and are associated with sieve tubes, the common wall between companion cell and sieve tube shows the presence of five pits which are transversed by plasmodesmata. The companion cells are absent in pteridophytes and gymnosperms. >Phloem parenchyma :These cells are living and store food in the form of starch and fats. They are absent in monocots. In secondary phloem, they are oriented in vertical as well as radial direction. The cells of the radial system are called phloem ray cells. Main function of phloem parenchyma is translocation and storage of food reserves. >Phloem fibers : They have cellulose and lignified thickenings. They are non – living cells that provide mechanical support to plants. They are also known as bast fibres. They have a great commercial use as they have great tensile strengt...

ADVERTISEMENTS: In this article, we will discuss about the complex tissues of plant cell. Xylem and phloem are the two complex tissues which are discussed hereunder. The complex tissues are heterogeneous in nature, being com­posed of different types of cell elements. The latter remain contiguous and form a struc­tural part of the plant, adapted to carry on a specialised function. Xylem and phloem are the complex tissues which constitute the component parts of the vascular bundle. They are also called vascular tissues. ADVERTISEMENTS: The vascular system occupies a unique position in the plant body, both from the point of view of prominence and physiological importance. The term ‘vascular plants’ has been in use since a long time. In recent years a new phylum Tracheophyta has been introduced to include all vascular plants; it covers pteridophyta and spermatophyta of old classifications. Vascular bundles form a continuous and inter­connected system in the different organs of the plants. They are primarily responsible for transport of water and solutes and elaborated food matters. Xylem: Xylem is a complex tissue forming a part of the vascular bundle. It is primarily ins­trumental for conduction of water and solutes, and also for mechanical support. Primary xylem originates from the procambium of apical meristem, and secondary xylem from the vascular cambium. As a complex tissue it consists of different types of cells and elements, living and non-living. ADVERTISEMENTS: The t...

ADVERTISEMENTS: In this article, we will discuss about the complex tissues of plant cell. Xylem and phloem are the two complex tissues which are discussed hereunder. The complex tissues are heterogeneous in nature, being com­posed of different types of cell elements. The latter remain contiguous and form a struc­tural part of the plant, adapted to carry on a specialised function. Xylem and phloem are the complex tissues which constitute the component parts of the vascular bundle. They are also called vascular tissues. ADVERTISEMENTS: The vascular system occupies a unique position in the plant body, both from the point of view of prominence and physiological importance. The term ‘vascular plants’ has been in use since a long time. In recent years a new phylum Tracheophyta has been introduced to include all vascular plants; it covers pteridophyta and spermatophyta of old classifications. Vascular bundles form a continuous and inter­connected system in the different organs of the plants. They are primarily responsible for transport of water and solutes and elaborated food matters. Xylem: Xylem is a complex tissue forming a part of the vascular bundle. It is primarily ins­trumental for conduction of water and solutes, and also for mechanical support. Primary xylem originates from the procambium of apical meristem, and secondary xylem from the vascular cambium. As a complex tissue it consists of different types of cells and elements, living and non-living. ADVERTISEMENTS: The t...

Hint: Vascular plants have vascular bundles which help in the transportation of various substances. There are two types of vascular bundles found in plants - Xylem and Phloem. Complete answer: Phloem is basically a living tissues which helps in conduction of soluble organic compounds which are produced during the process of photosynthesis downwards from leaves, The components of phloem are: - >Sieve element :They are long tubular structures and are placed one above the other forming a sieve tube. They lack a nucleus. Sometimes they have a special type of thickening called nacreous thickening. Sieve tubes are syncytes i.e. formed by fusion of cells. >Companion cell:They are living, and are associated with sieve tubes, the common wall between companion cell and sieve tube shows the presence of five pits which are transversed by plasmodesmata. The companion cells are absent in pteridophytes and gymnosperms. >Phloem parenchyma :These cells are living and store food in the form of starch and fats. They are absent in monocots. In secondary phloem, they are oriented in vertical as well as radial direction. The cells of the radial system are called phloem ray cells. Main function of phloem parenchyma is translocation and storage of food reserves. >Phloem fibers : They have cellulose and lignified thickenings. They are non – living cells that provide mechanical support to plants. They are also known as bast fibres. They have a great commercial use as they have great tensile strengt...