Plant Structure & Function

Main Plant Tissues Dermal Tissue - covers the outside of the plant & protects it –May produce a waxy coating to prevent water loss Ground Tissue - inside the dermal tissue; provides support, stores materials, & is the site of photosynthesis Vascular Tissue - transports water & nutrients throughout the plant –Xylem transports water –Phloem transports food

Plant Tissues See fig on pg. 642

Roots Roots anchor plants & absorb mineral nutrients & water from the soil Parts: –Vascular cylinder in center of root –Root hairs increase surface area to absorb water & nutrients –Root cap protects the growing part of the root –Meristem is where growth occurs

Root Structure See fig.21.7 on pg. 648

Stems Stems support plants, transport materials, & provide storage Primary growth takes place in apical meristems & makes stems grow taller Secondary growth takes place in lateral meristems & adds to the width of the stem

Stem Growth See pg.651

Leaves Leaves collect sunlight for photosynthesis The top of a leaf contains most of the chloroplasts & is where most photosynthesis takes place The underside of a leaf is the site of transpiration & gas exchange –Gases are exchanged through openings called stomata, which are opened & closed by surrounding cells called guard cells

Stomata & Guard Cells Fig on pg. 652Fig on pg. 652

Plant Reproduction

Angiosperms & Gymnosperms Angiosperms are flowering plants –Some flowers are strictly male OR female, some contain both male AND female reproductive structures –Fertilization produces seeds which are contained within a fruit Gymnosperms are cone-bearing plants –Male cones produce pollen, female cones contain ovules to be fertilized –Fertilization produces seeds which are contained in the scales of the cones

Flowers Flowers contain sepals and petals, which are often brightly colored to attract pollinators The stamen is the male part –Filament supports the anther –Anther produces pollen grains The pistil is the female part –Stigma is at the top & collects pollen –Style is the tube leading from the stigma to the ovary –Ovary is where the egg cells are located

Parts of a Flower Fig on pg. 668

Reproduction of Flowering Plants (Angiosperms) Flowers can either self-fertilize or pollen can be carried to another flower to fertilize When pollen fertilizes the egg cells, seeds form The ovary grows to become a fruit surrounding the seeds Fruit aids in the dispersal of seeds to new areas

Reproduction of Conifers (Gymnosperms) Male cones release pollen, which is carried by the wind to female cones Ovules within the scales of the female cones are fertilized and seeds develop Gymnosperm means “naked seed”