Why are xylem and phloem called complex tissue

Xylem and phloem are known as complex tissues as they are made up of more than one type of cells. These cells work in a coordinated manner, as a unit, to perform the various functions of the xylem and phloem. Xylem helps in conducting water and minerals. It also provides mechanical support to plants. It is made up of the following components: 1 Tracheids (xylem vessels and xylem tracheids) 2 Xylem parenchyma 3 Xylem fibres Tracheids are elongated, thick-walled dead cells with tapering ends. Vessels are long, tubular, and cylindrical structures formed from the vessel members, with each having lignified walls and large central cavities. Both tracheids and vessels lack protoplasm. Xylem fibres consist of thick walls with an almost insignificant lumen. They help in providing mechanical support to the plant. Xylem parenchyma is made up of thin-walled parenchymatous cells that help in the storage of food materials and in the radial conduction of water. Phloem helps in conducting food materials. It is composed of: 1 Sieve tube elements 2 Companion cells 3 Phloem parenchyma 4 Phloem fibres Sieve tube elements are tube-like elongated structures associated with companion cells. The end walls of sieve tube elements are perforated to form the sieve plate. Sieve tube elements are living cells containing cytoplasm and nucleus. Companion cells are parenchymatous in nature. They help in maintaining the pressure gradient in the sieve tube elements. Phloem parenchyma helps in the storage of...

The anatomy of flowering plants includes the organisation of cells and tissues within the bodies of flowering plants. Tissues are formed by a group of cells to perform a function., Plant tissues are classified into two types based on their ability to divide. They are Merismatic and permanent tissue. Merismatic tissue This is the simple tissue that has the ability to continuous cell division. In this type of tissue, growth occurs in the roots and shoot tips of the plant. Based on the region of meristematic tissue in the plant body, we can group the meristems into three types. They are: • Apical Meristems – These meristems are situated at the tips of roots and shoots. • Intercalary Meristems – The intercalary meristems are situated at the internodes or the foundation of the leaves. • Lateral Meristems – These are available on the lateral side of the stem and foundation of a plant. Permanent tissue These tissues are derived from the merismatic tissues and have lost their capacity to divide. This type of tissue can be found in mature plants. They are classified into two types- Simple and complex tissue Simple tissue: This is also called homogeneous tissue which consists of a single type of cells. Simple tissues are of three types which are parenchyma, collenchyma and sclerenchyma. • Parenchyma: These tissues are found in the delicate pieces of a plant like the roots, stems, leaves, and blossoms. The cells of this tissue contain huge intercellular spaces between them. Every cel...

Xylem and phloem are known as complex tissues as they are made up of more than one type of cells. These cells work in a coordinated manner, as a unit, to perform the various functions of the xylem and phloem. Xylem helps in conducting water and minerals. It also provides mechanical support to plants. It is made up of the following components: Tracheids (xylem vessels and xylem tracheids) Xylem parenchyma Xylem fibres Tracheids are elongated, thick-walled dead cells with tapering ends. Vessels are long, tubular, and cylindrical structures formed from the vessel members, with each having lignified walls and large central cavities. Both tracheids and vessels lack protoplasm. Xylem fibres consist of thick walls with an almost insignificant lumen. They help in providing mechanical support to the plant. Xylem parenchyma is made up of thin-walled parenchymatous cells that help in the storage of food materials and in the radial conduction of water. Phloem helps in conducting food materials. It is composed of: Sieve tube elements Companion cells Phloem parenchyma Phloem fibres Sieve tube elements are tube-like elongated structures associated with companion cells. The end walls of sieve tube elements are perforated to form the sieve plate. Sieve tube elements are living cells containing cytoplasm and nucleus. Companion cells are parenchymatous in nature. They help in maintaining the pressure gradient in the sieve tube elements. Phloem parenchyma helps in the storage of food and is m...

In this explainer, we will learn how to describe the structure and function of different tissues found in plants. Have you ever wondered while eating a stick of celery why it is so crunchy? Or have you ever wondered while enjoying a pear why it feels a little gritty? This is because of the different types of cells found in specific plant tissues, as well as the chemical and structural components they contain. A tissue is a group of specialized cells that carry out a particular function. In celery, many cells group together to make the tissues found in the stalk, which you can see tapering into leaves in the image below. Figure 1 The pressure of water on the cell walls in this stalk tissue gives it a signature crunch when bitten into. Lignin is an organic polymer that deposits in the cell walls of some plant cells to provide mechanical support to resist various stresses, and it is what gives the pear fruit its gritty texture. Plants are fantastically diverse in their internal structure, but most of them have certain properties and tissues in common. Definition: Tissue A tissue is a group of specialized cells that work together to carry out specific functions. There are two main types of tissues in plants: simple tissues and compound (or complex) tissues. The micrograph below shows part of a cross section of a pumpkin stem revealing some of the differences between simple and compound tissues. Figure 2 Simple tissues are generally composed of one type of cell. There are three...

Comparison chart Phloem versus Xylem comparison chart Phloem Xylem Function Transportation of food and nutrients such as sugar and amino acids from leaves to storage organs and growing parts of plant. This movement of substances is called translocation. Water and mineral transport from roots to aerial parts of the plant. Movement Bidirectional (Moves up or down the plant's stem from "source to sink") Unidirectional (Moves up the plant's stem) Occurrence Roots, stems and leaves. transports sucrose to growth (roots and shoots) and storage regions of the plant (seeds fruit and swollen roots) Roots, stems and leaves Additional Functions Forms vascular bundles with xylem Forms vascular bundles with phloem and gives mechanical strength to plant due to presence of lignin cells. The lignified secondary wall also makes the xylem waterproof and prevent it from collapsing under the pressure of water transpiration Structure Elongated, tubular shape with thin walled sieve tubes. The sieve tubes have pores at each end in the cross walls and Tubular shape with no cross walls which allows a continuous column of water + facilitates more rapid transport within the xylem vessels. There are two types - protoxylem (first formed xylem) + metaxylem (mature xylem) depending on pattern of lignin. Elements Sieve tubes, companion cells, phloem parenchyma (loosely packed resulting in intercellular spaces which allows gas exchange), bast fibers, intermediary cells, Tracheids, vessel elements, xylem pa...

\( \newcommand\) • • • • Xylem and phloem form the vascular system of plants to transport water and other substances throughout the plant. Key Points • Xylem transports and stores water and water-soluble nutrients in vascular plants. • Phloem is responsible for transporting sugars, proteins, and other organic molecules in plants. • Vascular plants are able to grow higher than other plants due to the rigidity of xylem cells, which support the plant. Key Terms • xylem: a vascular tissue in land plants primarily responsible for the distribution of water and minerals taken up by the roots; also the primary component of wood • phloem: a vascular tissue in land plants primarily responsible for the distribution of sugars and nutrients manufactured in the shoot • tracheid: elongated cells in the xylem of vascular plants that serve in the transport of water and mineral salts Vascular Tissue: Xylem and Phloem The first fossils that show the presence of vascular tissue date to the Silurian period, about 430 million years ago. The simplest arrangement of conductive cells shows a pattern of xylem at the center surrounded by phloem. Together, xylem and phloem tissues form the vascular system of plants. Figure \(\PageIndex\): Tracheids and vessel elements: Tracheids (top) and vessel elements (bottom) are the water conducting cells of xylem tissue. Phloem tissue is responsible for translocation, which is the transport of soluble organic substances, for example, sugar. The substances trave...