Plants have three basic organs, roots stems and leaves. Describe in detail the types of cells and tissue involved with each organ and their function in transport mechanisms in plants.
Since this is not my area of expertise, I searched Google under the key words "cells leaves roots stems" to get this:
http://www.google.com/search?client=safari&rls=en&q=cells+leaves+roots+stems&ie=UTF-8&oe=UTF-8
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
Roots:
Roots are the underground portion of the plant, responsible for anchoring the plant in the soil and absorbing water and nutrients. They are comprised of various types of cells and tissues that contribute to their transport mechanisms.
1. Root Epidermis: The outermost layer of cells in the root, it is responsible for absorbing water and minerals from the soil through root hairs.
2. Cortex: The cortex consists of parenchyma cells and is responsible for storing nutrients. It also helps in the lateral movement of water and minerals towards the vascular tissue.
3. Endodermis: The endodermis is a single layer of tightly packed cells that surrounds the vascular tissue. Its primary function is to regulate the movement of water and solutes into the vascular tissue through the Casparian strip.
4. Pericycle: Located just inside the endodermis, the pericycle contains the primary meristematic cells. It is responsible for producing lateral roots and plays a role in water and nutrient uptake.
5. Xylem: The xylem tissue consists of tracheids and vessel elements, which are responsible for the transport of water and minerals from the roots to the stems and leaves.
6. Phloem: The phloem tissue comprises sieve tubes and companion cells. It is responsible for the transportation of organic compounds, such as sugars, from the leaves to other parts of the plant.
Stems:
Stems connect the roots and leaves, providing support and transportation of materials. They possess specific cell types and tissues that aid in transport mechanisms.
1. Epidermis: The outermost layer of cells in the stem, the epidermis protects the underlying tissues and controls gas exchange.
2. Cortex: The cortex consists of parenchyma cells that store carbohydrates and provide support to the stem.
3. Vascular Bundles: The vascular bundles are composed of xylem and phloem tissues. Xylem transports water and minerals upwards, while phloem transports sugars and other organic compounds downwards.
4. Cambium: The cambium is a meristematic tissue located between the xylem and phloem. It is responsible for the production of secondary xylem and phloem, aiding in the growth of the stem.
Leaves:
Leaves are the main site of photosynthesis and transpiration in plants. They possess specialized cells and tissues that contribute to their transport mechanisms.
1. Epidermis: The upper and lower epidermis form a protective layer around the leaf. The upper epidermis contains stomata, which allow for gas exchange and regulate water loss.
2. Mesophyll: The mesophyll is the main site of photosynthesis, composed of two distinct layers - the palisade mesophyll and spongy mesophyll. Palisade mesophyll contains tightly packed cells with chloroplasts, while spongy mesophyll consists of loosely arranged cells for gas exchange and storage.
3. Xylem and Phloem: Similar to stems, leaves also contain xylem and phloem tissues. Xylem transports water and minerals from the roots to the leaves, while phloem transports sugars and other organic compounds produced during photosynthesis to other parts of the plant.
Understanding the types of cells and tissues involved in each organ of a plant provides insight into their functions in transport mechanisms. The coordination of these cells and tissues ensures the efficient movement of water, nutrients, and other essential substances throughout the plant.