Plants Flashcards
Root system-
underground- absorbs
water and minerals from the soil
Shoot system-
aboveground- absorb light and CO2 Stem o Leaves o Flowers/ fruits
Ground tissue system-
plant body–functions in photosynthesis, storage, and support
Vascular tissue system-
conducting system–transports water, minerals, food
Dermal tissue system-
provides covering for plant
Ground tissue system
Composed of 3 different types of tissue. Growing plant cell secretes thin flexible primary cell wall. After stops growing- secondary cell wall- inside primary cell in between plasma membrane and primary cell wall
more rigid and cell can no longer grow after scw
put down. Each of the three tissues contain different types of cell walls, making the structure of the cells range from very soft and flexible (most common parts of plants) to very hard (cells found in wood, bark, nuts, etc)
Xylem
Vascular. conducts water and dissolved nutrient materials from roots to stems and leaves. Cells are hollow and dead at maturity
Phloem
Vascular. conducts food materials (carbs formed by photosynthesis). Cells alive at maturity
Epidermis-
Dermal tissue system. outermost layer of herbaceous plants. Transparent- no chloroplasts. Secrete waxy cuticle which restrict water loss. has stomata.
stomata
pores in epidermis that allow for gas exchange
Guard cells-
surround stomata
Trichomes-
outgrowth or hairs in epidermis (called root hairs in roots)
Periderm-
replaces epidermis in woody plants
Leaf tissues
Upper epidermis covers upper layer, lower epidermis covers lower layer. Mesophyll, bundle sheath, veins
Mesophyll-
photosynthetic ground tissue of the leaf. Loosely arranged with many air spaces- allows for rapid gas diffusion. Palisade mesophyll- closely packed, spongy mesophyll looser.
Bundle sheath-
nonvascular cells surrounding larger veins
Veins-
vascular bundles containing xylem and phloem
Transport in Plant Body
Water and dissolved nutrient minerals are transported from roots to other parts of the plant in xylem- only moves upward. Dissolved sugar is translocated in phloem- can move upward or down. Driven by physical forces, not by a pumping organ
Transpiration-
loss of water vapor by evaporation , mostly through stomata
Environmental factors affecting transpiration:
Higher temps and more light–>stomates to open more
wind and dry air–more transpiration
humidity–less transpiration
Importance: transpiration
responsible for water movement from soil to leaves
cools stem and leaves and Distributes dissolved minerals through plants
how might transpiration be harmful?
Too much transpiration- plant can wilt and die
what cycle is transpiration a part of?
Part of hydrologic cycle- water cycles from ocean and land back to atmosphere, then back to ocean and land Water evaporates from leaves and stems to form clouds in atmosphere
Guttation-
liquid water is forced out of plant. Occurs at night, when no transpiration is occurring but there is moist soil