Important Survival Structures and Adaptations in Plants

Vascular Tissue- Nutrition

• Vascular Tissue move fluids through the plant body– 1. Xylem– carries water from the root to the other

parts of the plant– 2. Phloem – transports nutrients and

carbohydrates made by photosynthesis

Vascular Tissue Chart-NutritionTissue System and Its Functions

Component Tissues Location of Tissue Systems

Dermal Tissue System • protection • prevention of water loss

Epidermis Periderm (in older stems and roots)

Ground Tissue System • photosynthesis • food storage • regeneration • support • protection

Parenchyma tissue Collenchyma tissue Sclerenchyma tissue

Vascular Tissue System • transport of water and minerals • transport of food

Xylem tissue Phloem tissue

Leaves-Nutrition

• Designed for absorbing light and carrying out photosynthesis

• Two types of leaves:– 1. Simple (one leaf)

– 2. Compound (many leaflets)

Leaf Functions-Nutrition• Carries out photosynthesis

• Transpiration- evaporation of water through leaves

• Gas Exchange– Stomata remains open enough just to allow

photosynthesis to take place

Layers of Leaf- Nutrition&Respiration

– Cuticle- outer waxy surface of the leaf that prevents drying out

– Mesophyll spongy layer is composed of many chloroplasts

– Palisade mesophyll – absorb the light

– Spongy mesophyll – air spaces that connect the stomata with outside

– Stomata – pore-like openings on the underside of a leaf to absorb carbon dioxide

– Cuticle- outer waxy surface of the leaf that prevents drying out

Stomata On Surface of Leaf- Respiration Swollen Guard Cells

Flaccid (weak) guard cells

Small stoma opening little gas exchange

Large stoma opening ample gas exchange

How the stomata helps to maintain homeostasis?

• The stomata allows for the plant to REGULATE the exchange of gases MAINTAIN HOMEOSTASIS– Dependent on the availability of water• When water is plentiful plant can accept more

water guard cells swell stomata opens gas exchange can occur readily• When water is NOT plentiful OR wants to conserve the

water it has guard cells shrink stomata closes gas exchange slows down

Cones in Conifer Plants- Reproduction

• Cones and pollen are used as the reproductive structures found in gymnosperms

• Exhibit alternation of generations sporophyte and gametophyte phases.

• http://bcs.whfreeman.com/thelifewire/content/chp30/30020.html

Reproduction in Angiosperms-Reproduction

• Also exhibit sporophyte and gametophyte generations

• http://www.sumanasinc.com/webcontent/animations/content/angiosperm.html

Flower Parts-Reproduction

• Flowers are the reproductive structure in angiosperms.

Stamen-> men=male• Male: anther+filament• Contains pollen

• Pistil (carpel)-> female– Stigma,style,ovary– Ovary holds the ovules.

Seeds-Reproduction

• Seeds in plants play an important role in– Protection of the plant

embryo– Prevention of drying out

of moisture within the seed

– Provides nutrients as it develops

Monocot vs Dicot Seeds

Summary Tutorial

• http://wps.prenhall.com/wps/media/objects/838/858365/ch03anim/3_1_6_1a.swf

How Do Plants Respond to the Environment?

• 1-Tropism= response by a plant to an external stimulus– Phototropism response to light– Gravitropism response to gravity– Hydrotropism response to water– Thigmotropism response to touch (surfaces like vines

wrapping around)

• 2-Hormones= auxins– cytokinins, gibberlins, ethylene

Plant Auxins- Response to Environment

• Auxins substances that regulate cell growth at the tip of plant by stimulating cell elongation.– CytokininsStimulate cell division, and cause

dormant seeds to sprout. – Gibberillinsdramatic increase in size (stems and

fruits)– Ethylene Stimulate fruits to ripen

Other Environmental Adaptations- Response to Environment

• Aquatic PlantsTissues with large air filled spaces for oxygen diffusion

• Epiphytes-Grow directly on other plants to obtain their nutrients Ex. Spanish Moss

• Desert Plants (Xerophytes)-Extensive roots,reduced leaves, & thick stems stores water.• Nutrition Specialists-Live in areas with low

concentrations of nutrients in the soil. – Ex. Carnivorous plants (Venus Fly Trap)– Parasites (Mistletoe)