विच टिशु हेल्प्स इन ट्रांसपोर्टेशन ऑफ वाटर एंड मिनरल्स टू द प्लांट
Answers
Answer:
The answer is xylem tissue
Explanation:
Answer: Explanation:
Transport system in plants
Transport in biology means carrying substance absorbed or made in the body of an organism to all other parts of its body.In plants, it is only water and minerals that need to be transported to its other parts. Another thing that needs to be transported to other parts of the plants is the food prepared in leaves. This is because a plant has a branching shape so it gets carbon dioxide for photosynthesis and oxygen for respiration from air directly through diffusion.So, for this plants need transport system in their body to supply all their cells with food, oxygen, water etc.
Transport of water and minerals
Plants need water to make food through the process of photosynthesis and minerals for making proteins. Thus, a plant absorbs water and minerals from soil through roots and transport it other parts like stem, leaves, flowers etc. It is through two kinds of elements of xylem tissue called, xylem vessels and tracheid that water and minerals move from roots of a plant to its leaves.
The two types of conducting tissues that perform the function of transport system in plants are:
1) Xylem
2) Phloem
Xylem vessels
Xylem vessel is a long tube made up of dead cells joined end to end. It is a non-living tube which runs from roots of the plants and runs through the stem and reaches every leaf. The end walls of the cells are broken so that an open tube is formed.Xylem vessels do not have cytoplasm or nuclei and the walls of the vessels are made of cellulose or lignin. Other than transporting water and minerals, xylem vessel also provides strength to the stem and keeps it upright. This is because lignin is very hard and strong. Wood is made of lignified xylem vessels. Xylem vessels have pits in their cell walls where lignin is not deposited. Either xylem vessel or both xylem vessel and tracheids transport water in flowering plants.
Tracheids
In non-flowering plants tracheids are the only water conducting tissues. Tracheids are dead cells with lignified walls with no open ends. They are long, thin and spindle shaped cells. They have pits in them and it is through pits only that water flows from one tracheid to another. All the plants have tracheid in them.
Epidermis : The outer layer of the cells in the root of a plant is called epidermis.The thickness of epidermis is equal to one cell.
Endodermis : It is the layer of cells around the vascular tissue (xylem and phloem) in the root of a plant. Endodermis is the innermost layer of cortex.
Root cortex : It is the part of root between the epidermis and endodermis.
Root xylem : It is the xylem tissue present in the roots. It is present at the centre of the root.
Epidermis, root cortex and endodermis are present between the root hair and root xylem. So, the water which is absorbed by the root hairs from soil first passes through epidermis, root cortex and endodermis and then finally reaches to root xylem.Also, minerals are present in soil. Plants take these minerals from soil in inorganic form such as nitrates and phosphates. Minerals from soil gets dissolve in water to form an aqueous solution. So, when water is transported from roots to leaves, minerals dissolved in water is also transported.
Mechanism of transport of water and minerals in a plant
Root hair absorbs the water containing dissolved minerals from the soil. Root hair is directly in contact with the film of water present in-between the soil particles. Water containing minerals gets into the root hair and passes from cell to cell through the process of osmosis and reaches epidermis, root cortex, endodermis and root xylem.Xylem vessels of the root are connected with the xylem vessel of the stem of a plant. So the water enters from root xylem vessel to the stem xylem vessel and further reaches into the leaves of the plant from petiole. The plant uses only one or two per cent of the water in photosynthesis. The remaining water is lost in air as water vapour.
Water is sucked up by the xylem vessel
The pressure at the top of the plant (in the leaves) is low whereas pressure at the bottom of the plant is high. It is due to transpiration that the pressure is low at the top of a plant. And it is because of low pressure at the top of the plant that water flows up the xylem vessel into the leaves of a plant.The continuous evaporation of water from the leaves of a plant is called transpiration. The leaves of a plant have tiny pores called stomata. It is through them that the water evaporates into the air. This reduces the pressure at the top of xylem vessels and thus water flows up into them.