Plant Structure and Growth

University:
College
Course:
College Biology
Academic year:

2023
Views:

413

Pages:

1
Author:

anon

Plant structure and growth Plant stem Epidermis - Layer of cells normally covered with a waxy cuticle to prevent water loss Cortex - Tissue on the outer edge of the stem which often contains cells with secondary thickening on the cell walls to provide extra support for the stem Vascular bundle – Longitudinal set of tubes consisting of phloem and xylem tubes. They are responsible for the transportation of different substances around the plant (Contains xylem, phloem and cambium tissue) Xylem – Longitudinal set of tubes which transport water from the roots upwards to the leaves. Phloem – Responsible for transporting products of photosynthesis such as glucose around the plant. Cambium – A type of lateral meristem found between the xylem and phloem tubes that forms a vertical cylinder in the stem. Produces the secondary phloem and xylem through cell division. Pith tissue – Found in the centre of the stem Leaf Upper epidermis – Layer of cells found on top of the leaf covered in a waxy cuticle to prevent water loss. Palisade mesophyll – Densely packed with chloroplasts, allowing photosynthesis to occur. Found on the upper portion of the leaf, where light is the most intense. Spongy mesophyll – Cells here are loosely packed, with few chloroplasts. The cells being loosely packed allows for gas exchange to occur. Found on the lower portion of the leaf, close to the lower epidermis. Stoma – Pore that allows CO2 for photosynthesis to diffuse in and O2 to diffuse out Guard cells – Pair of cells found on the stoma which control when they close and open in order to control the amount of transpiration. Lower epidermis – The bottom layer of cells on a leaf which contains the stoma and guard cells. Has a thinner wax cuticle, as it is in a cooler position. Remember that the xylem is closer to upper epidermis, while the phloem closer to lower epidermis