Vascular Plants                                   

Three parts of a vascular plant Root – anchor Stem – support Leaves – food production

The vascular system Xylem – transports water and minerals from roots to the rest of the plant Phloem – transports sugars made by leaves down to the rest of the plant

The vascular system (cont.)

Seed Plants Gymnosperms – seeds develop on cone scales Conifers are most common (ex. Pine, spruce, fir, etc) Very hardy and can endure harsh conditions Waxy needles prevent water loss Shallow roots allow stability in little soil

Gymnosperms

Seed Plants (cont.) Angiosperms – flowering plants that produce seeds that are enclosed in fruits Monocots have one cotyledon (ex. Grasses and other herbaceous plants) Dicots have two cotyledons (ex. Most of the woody plants) (Cotyledons are embryonic leaves found in the seed)

Angiosperms Monocot v. Dicot

Flowers and Fruit Flowers contain both male and female reproductive organs Fruits – after the zygote is formed, the petals fall away and the remaining parts develop into a fruit Fruits protects seeds and helps to disperse them

Flowers and Fruit

Kinds of plant tissue Epidermis – outermost layer of plant cells – serves as protection Vascular tissue – consists of xylem and phloem – transport H2O, dissolved minerals and sugars Ground tissue – in between tissue that cushions and protects or stores food and water

Roots Root hairs create more surface area to absorb water and minerals from the soil Pith – acts as support and storage Meristem is where mitosis takes place

Stems Woody stems – the xylem and phloem produce new layers of plant tissue giving the stem strength and makes the stem wider in diameter Many dicots and most gymnosperms have woody stems

Stems (cont.) Buds – usually develop in the fall Meristematic cells are here and go through mitosis which helps the plant to grow in height and length

Leaves Blade – the broad part of a leaf; contains most of the photosynthetic cells Petiole – aka leaf stalk; supports the blade Simple – a single, undivided blade Compound – blade is divided into separate parts and attached to an extension of the petiole

Simple Leaves

Compound Leaves

Structure of the Leaf Epidermis – innermost single, transparent layer of cells Cutin – secreted by the epidermis – slows evaporation and protects Stomata with guard cells – allows water, carbon dioxide and oxygen to enter and leave the leaf (stomata is the opening and guard cells regulate the size of the opening)

Stomata and Guard Cells

Structure of the leaf (cont.) Mesophyll – middle portion of the leaf – cells with chlorophyll and other pigments are found here

Leaves and water loss Transpiration 90% of the water absorbed by the roots is lost through transpiration, so water is continuously resupplied through roots

Reproduction The Flower

The flower (cont.) The pistil is the female part and includes: Stigma – contains a sticky substance to attach pollen grains Style Ovary – contains ovules or eggs

The Flower (cont.) The stamen is the male part and includes Filament Anther – pollen is produced here

Sexual Reproduction - polliation Pollination – the process of transferring ripe pollen from the anther to the stigma Self pollination – when pollen falls from an anther to a stigma on the same flower Cross pollination – when a stigma traps pollen from another plant Pollination can be aided by animals, wind and water

Sexual Reproduction - fertilization Fertilization start when a pollen grain lands on a stigma Then a pollen tube forms towards the ovule in the ovary As it makes its way, a cell inside divides into 2 sperm and go down pollen tube 1 sperm fertilizes, the other helps make food for the embryo (endosperm)

Pollination and Fertilization

Fruits and Seeds Once fertilization has occurred the ovule changes to become a seed All of the seeds are located inside the ovary As the seeds mature, the ovary ripens and is called a fruit A fruit can be fleshy (oranges, apples, peaches) or dry (peanuts, burrs and “helicopters” from maples)