BIOL 242 Study Guide - Midterm Guide: Rock Sand, Monotropa Uniflora, Topsoil
Document Summary
If they have chloroplast they are called chlorenchyma: collenchyma. Has primary cell wall that is unevenly thickened. Dead at maturity, but functional- protoplast gone. Lignified secondary cell wall provides support without turgor pressure. Secondary cell wall is created within primary cell wall, first is made of cellulose, second is cellulose and lignin. Tissues are conglomerations of cells, they do not have to be all the same type but they can be. Four tissue types: dermal, ground, vascular, meristematic. Dermal tissue: covers surfaces of all plant organs (epidermis, made up of mostly modified parenchyma cells, do not have isodiametric shape, secretes cuticle (cutin) Cutin- decreasing loss of water from plant parts exposed to air: usually non-photosynthetic- do not contain chloroplast. Vessels (found only in angiosperms)- wider barrel shaped cells linked together to make tubes, cross walls are dissolved away. Tracheids (found in angios and gymnos)- spindle shaped.
