PLANTS – DAY 3 MONOCOT & DICOTS

INTRODUCTION  There are different classes of plants – one of these classes of plants are called ___________________, and these plants produce flowers.  Angiosperms can be further divided into 2 subclasses: Monocotyledoneae and the Dicotyledoneae, aka _______ ________________________  Names of 2 subgroups are based on structure of their ___________

SEEDS  The ___________, which surrounds the plant embryo and protects it from desiccation in the uncertain conditions of a terrestrial environment, is one of the adaptations that has allowed plants to thrive as they gradually moved from water to land.  Each seed consists of an embryo, food source, and protective outer coat; it can lie dormant for some time before germinating, waiting until environmental conditions are right  Monocots have only ________________ - cotyledon  Dicots have ________ cotyledons or seed leaves  Cotyledons

MONOCOT & DICOT SEEDS

EXAMPLES OF MONCOTS & DICOTS:  MONOCOTS: Onion, corn, rice, sugarcane  DICOTS: tomatoes, cabbage, apples, peaches

SUMMARY OF DIFFERENCES: DICOTS MONOCOTS

TISSUE TERMS  Vascular cambium/cylinder: __________________ tissue responsible for creating new xylem and phloem tissue  Pith: the parenchyma tissue at the very center of roots AND stems. Functions in storage of nutrients, carbohydrates and water  Cortex: parenchyma tissue surrounding the pith; made of rigid cells in roots AND stems  Pericycle: a thin layer of lateral meristematic cells that surrounds the vascular cylinder; helps for secondary roots to grow  Endodermis: layer of rectangular cells surrounding the vascular cylinder; innermost layer of the cortex; regulates movement of water and minerals  Epidermis: the outermost layer of a multicellular plant experiencing growth  Vascular Bundles: collections of xylem and phloem tissue, separate from other collections of cells, running longitudinally - includes xylem and phloem

ROOT TISSUE DIFFERENCES Xylem in center of root in an ‘X’ shape; phloem is outside of xylem Vascular bundles are arranged in a ring shape

MONOCOT ROOT CROSS SECTION

DICOT ROOT CROSS SECTION CORTEX EPIDERMIS

STEMS – MONOCOT & DICOT

DICOT STEM CROSS SECTION In herbaceous dicots, bundles are arranged in a ring A thin layer of tissue called vascular cambium between xylem and phloem – can appear as a hollow area in the plant (buttercup)

MONOCOT STEM CROSS SECTION MONOCOT STEM VASCULAR BUNDLE Herbaceous monocots have vascular bundles scattered throughout the stem (corn)