Plant Structure & Function Ms. Williams Biology Ms. Williams Biology

Plant Tissue Systems  Dermal Tissue - covers the outside of the plant and protects it; outermost layer  Ground Tissue - provides support and stores material in roots and stems; middle layer  Dermal Tissue - covers the outside of the plant and protects it; outermost layer  Ground Tissue - provides support and stores material in roots and stems; middle layer

Plant Tissue Systems  Vascular Tissue - transports water, mineral nutrients and organic compounds to all parts of the plant; surrounded by ground tissue

Two types of vascular tissue  Xylem - carries water and dissolved materials up the plant from the roots  Phloem - carries sugars from photosynthesis down from the leaves  Xylem - carries water and dissolved materials up the plant from the roots  Phloem - carries sugars from photosynthesis down from the leaves

Xylem & Phloem in a Stem

Roots  Anchor the plant into the soil  Absorbs water and minerals from the soil; this is done through a process called osmosis  Anchor the plant into the soil  Absorbs water and minerals from the soil; this is done through a process called osmosis

Roots  Parts of roots  Vascular cylinder - the center of the root, made of xylem and phloem  Root hairs - increase the surface area of a root  Root cap - protects the tip of root  Meristem - area of active cell growth  Parts of roots  Vascular cylinder - the center of the root, made of xylem and phloem  Root hairs - increase the surface area of a root  Root cap - protects the tip of root  Meristem - area of active cell growth

Roots  Types of roots  Fibrous roots - roots make fine branches in which most of the roots are the same size  Taproot - have a long, thick, vertical root with smaller branches  These can sometimes store food  Types of roots  Fibrous roots - roots make fine branches in which most of the roots are the same size  Taproot - have a long, thick, vertical root with smaller branches  These can sometimes store food

Types of Roots

Stems  Support plants  Transport materials  Water moves up a stem through a process called capillary action  Sugars move down a stem through a process called translocation  Support plants  Transport materials  Water moves up a stem through a process called capillary action  Sugars move down a stem through a process called translocation

Stems  Provide storage  Some stems grow underground, like potatoes  Provide storage  Some stems grow underground, like potatoes

Stems  Stems can grow 2 different ways  Primary growth - lengthens roots & stems  Secondary growth - widens roots and stems  This is how you get tree rings, which tell you the age of a tree  Stems can grow 2 different ways  Primary growth - lengthens roots & stems  Secondary growth - widens roots and stems  This is how you get tree rings, which tell you the age of a tree

Leaves  Contain chloroplasts which are the chlorophyll containing organelles used in photosynthesis  The blade is usually broad and flat and it collects the sunlight for the plant  The petiole connects the blade to the stem  Contain chloroplasts which are the chlorophyll containing organelles used in photosynthesis  The blade is usually broad and flat and it collects the sunlight for the plant  The petiole connects the blade to the stem

Leaves  The xylem and phloem make up the veins in a leaf

Leaves  The upper part of the leaf is where photosynthesis takes place  The underside of the leaf has stomata and is the site of transpiration and gas exchange  Stomata are pores on the underside of the leaf that are surrounded by guard cells  The upper part of the leaf is where photosynthesis takes place  The underside of the leaf has stomata and is the site of transpiration and gas exchange  Stomata are pores on the underside of the leaf that are surrounded by guard cells

Stomata & guard cells

Leaves  More than 90% of the absorbed water into a plant is lost to the atmosphere as water vapor through the stomata  This process is known as transpiration  More than 90% of the absorbed water into a plant is lost to the atmosphere as water vapor through the stomata  This process is known as transpiration

Transpiration