BIOL-1507EL Lecture Notes - Lecture 7: Lignin, Fruit Anatomy, Stoma

• School: Laurentian
• Department: Biology / Biologie
• Course: BIOL-1507EL
• Professor: Nasserulla Sabah

Document Summary

The walls of the outer epidermal cell covered with waxy cuticle. The epidermal cell contain stomata (guard cells and the stoma) Collenchyma: they are like parenchyma except they have thicker walls, the thickness is uneven and usually occurs in the corner of the cells collenchyma cells often form bundles beneath the epidermis they give flexible support to the plant (ex. Celery stalks) like parenchyma they stay alive at maturity sclerenchyma: they have thick secondary wall usually impregnated with lignin, which is an organic substance that make the cell wall tough and hard. Most sclerenchyma cell are non-living, their primary function is support, mostly found in bundles. There are two types of sclerenchyma cells; fiber and sclereids. Fiber: generally long, slender cell and commonly occur in strands or bundles. Sclereids: are variable in shape and they are often branched, short cell that make the seed coat, shelled nuts, and endocarp. There are two types of water conducting cells.