Exercise #3

Meristematic tissues cause ______ growth in all multicelllular, terrestrial plants and ______ growth in woody plants

Primary, Secondary

What are some examples of meristematic tissues?

Shoot Apical Meristem and Root Apical Meristem

Apical Meristem (Meristematic tissue)

Causes primary growth (lengthening of plants) which occurs at tips and shoots of roots and produces new leaves and flowers

Lateral meristems (Meristematic tissue)

Causes secondary growth (widening of plants) and occurs at the cambium and produces bark on trees

These types of tissues are a population of one cell type (mostly) with the exception of the epidermis

Simple tissues

What are some examples of simple tissues?

Parenchyma, Collenchyma, Sclerenchyma, Epidermal Cells, and Cork Cells

Parenchyma (simple tissue)

Large and thin walled cells that can be visualized with bubbles (Ranunculus and Zea)

Collenchyma (Simple Tissue)

Cells located beneath the epidermis of young stems with thickened cell walls that serve as strengthening tissues in new area of growth (Lab: Celery stalk wet mount)

Sclerenchyma (Simple Tissue)

These cells provide the main structural support and are dead at maturity

What are the two types of Sclerenchyma and some examples?

• Fibers - Tilia (basswood)

• Sclereids - Pyrus (pear) and stone cells (sclereid) wet mount

Epidermal Cells (Simple Tissues)

Outer covering cells (Syringia, lilac and Pelargonium, geranium)

Cork Cells (Simple Tissues)

Barrier that prevents water loss (Aristolochia, dutchman’s pipe)

These tissues consist of 2 or more cell types (such as a combination of parenchyma and sclerenchyma) and are vascular tissue that conducts fluids

Complex Tissues

What are some examples of complex tissues?

Xylem and Phloem

Xylem (Complex Tissues)

Conduct water (Pinus, tracheids and Helianthus, vessel elements)

Phloem (Complex Tissues)

Conduct nutrients and food (Zea (corn), stem)