Botany The Study of Plants

What Characteristics do ALL plants share? Autotrophs- Undergo Photosynthesis Eukaryotes- has nucleus Multicellular – more than one cell Have a Cell Wall (made of cellulose), have stomata, have Chloroplasts and Chlorophyll Similar cells in the plant make up tissues that perform specific jobs for the plant

Origin of Plants Biologists have learned which organisms are the ancestors of today’s plants by studying fossilized plants. Scientists have compared chlorophyll (the green substance in plant cells) of ancient algae to today’s plants to show how they are related.

What do Plants Need to Live on Land? Ways to OBTAIN water and nutrients (ROOTS) Ways to RETAIN water (CUTICLE) Ways to TRANSPORT water and nutrients (XYLEM and PHLOEM (vascular tissue)) Ways to SUPPORT their bodies (STEM, XYLEM, PHLOEM) Ways to REPRODUCE (sperm (pollen) and egg cells (ovules)) Open Books to page 114-115

Sporophyte Stage Gametophyte Stage

The first Terrestrial plants Mosses and ferns Mosses don’t have stems so they are very low to the ground http://www.ucmp.berkeley.edu/plants/bryophyta/sphagclump.jpg

The first Terrestrial plants This is an example of a moss Sporophyte growing out of a moss gametophyte. http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb3pg3_files/moss1.jpg

The first Terrestrial plants Ferns were more complicated When the young sporophyte emerges, it is essentially a parasite on the gametophyte until it can grow its first leaf. http://www.ucmp.berkeley.edu/plants/bryophyta/sphagclump.jpg http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/seedless%20plants/marchantia.jpg

The first Terrestrial plants This is the sporophyte stage of the fern with sori (spore cases). http://farm1.static.flickr.com/181/425553880_378f1e9e32.jpg?v=0

Characteristics of Seed Plants Vascular Tissue (Xylem and Phloem) Use Seeds to Reproduce Have Stems, Roots, Leaves They use the process of photosynthesis The plants you see are in the sporophyte stage. The gametophyte stage is microscopic.

Vascular Tissue

SEEDS A seed is a plant structure that contains a young plant inside a protective coating 3 Important Parts EMBRYO- young plant that develop from the zygote COTYLEDONS- stored food that the embryo uses before it can make its own SEED COAT- protective coating that surrounds the embryo

What do seeds need to develop into a plant? Water (first) Light Nutrients

Seed Dispersal Animals- eat fruits and deposit seeds or barbs hook onto fur Water- carries seeds (oceans, rivers) Wind- carries lightweight seeds Seeds shot out of the plant

Germination Early growth stages of the embryo Seed absorbs water (first) Seed coat softens The embryo uses stored food to begin to grow Roots grow first First leaves then emerge Seeds that are dispersed far away from the parent plant have a better chance to survive

Leaves, Stems, Roots Leaves Photosynthesis occurs here (upper leaf cells - chloroplasts) Gas and Water Exchange occur here (lower leaf cells - stomata) Water Exchange = Transpiration The cuticle, a waxy layer on the leaf’s upper portion helps to reduce evaporation from the leaf

Stems Herbaceous – soft stem. Dandelions, tomatoes, bean, corn, pea Woody – hard stem. Oak, maples, birch, black cherry Cambium- produces new phloem and xylem Heartwood- xylem that no longer transports water Pith- stores food and water Annual Rings- made of xylem cells, width of rings depends on growing conditions each year

Roots Anchor plant and absorb water and nutrients Root cap- dead cells that protect root as it grows through soil and rocks Fibrous root – several main roots that branch to form a tangled mass Tap root- 1 main root with thinner roots growing off of it (BEAN) CARROT CORN

Roots, Stems & Leaves (15 min)

Mosses Nonvascular plant Low-growing- grow close to ground No vascular tissue (no xylem or phloem) No roots, stems, or leaves Live where there is a lot of water

Ferns Seedless Vascular Plant Grow taller than mosses Use spores to reproduce Grow in moist surroundings Have roots, stems, leaves

Gymnosperms “Naked” Seeds Needle or scale like leaves Deep growing root systems Conifers - 1 type of gymnosperm, cone-bearing, most diverse type

Types of Gymnosperms Cycads – Look like palm tree with cones, found in tropical areas Ginkgos – Only one species exits today, can tolerate air pollution Gnetophytes – live in very hot deserts Conifers – Cone bearing plants, keep their needles year round.

Conifer Reproduction Cones- are the reproductive structures that hold the seed Most conifers produce both male and female cones Some produce only male or female Some produce no cones Male Cones- smaller than female, contain pollen (cells that turn into sperm cells) Female Cones- contain the ovule which holds the egg cell

Immature seeds in this female cone

Facts About Cones Ovules produce a sticky substance that helps to collect pollen Female cones stay on the tree for 2 years and male cones for 1 year Female cones with immature seeds point upward Female cones with mature seeds point downward

Gymnosperms Used to make paper, lumber, cellophane, rosin, rayon, and turpentine

Paper Production (5:30 min)

Baseball Bats (5:30 min)

Baseball Bats (cont)

Angiosperms Plants that produce seeds that are enclosed in a fruit Seeds develop in the ovary Angiosperms produce flowers and fruit

Types of Angiosperms (page 160) Dicot 2 cotyledons Leaf has branching veins Stem has circle of vascular tissue Flower has petals/sepals in groups of 4 or 5 Tap root Examples are roses, peanuts, dandelions, oak, maple, beans, apples Monocot 1 cotyledon Leaf has parallel veins Stem has scattered bundles of vascular tissue Flower has petals/sepals in groups of 3 Fibrous roots Examples are corn, grasses, wheat, rice, lilies, tulips and coconuts

Peanut Seed

Structure of Flowers Petals- attract pollinators (bees and humming birds) Sepals- protect the developing flower Stamens- male reproductive parts, made up of 2 parts Anther- where the pollen is produced Filament- holds and supports the anther Pistils- female reproductive parts, made up of 3 parts Stigma (sticky top), Style, (tube that leads to the ovary) Ovary (holds the ovules)

What Are the Parts of a Flower?                                                      

Do you know the parts of the flower?

Angiosperm Reproduction Plant produces the flower Anther produces pollen Ovary produces egg cells (2) Pollen is released and Stigma traps it Pollen produces a pollen tube through the style, into the ovules Sperm from pollen fertilizes each egg and the embryos develop Other parts of the ovule develop into the seed coat and cotyledons Ovary develops into the fruit

Angiosperms Used as an important source of food, clothing, rubber, furniture, and medicine

Fruit vs.Vegetable What is the difference you may ask???? Fruits are the edible part of a plant developed from a flower and contain seeds Vegetables are the edible parts of a plant such as roots, stems or leaves.

Fruit or Veggie????? fruit veggie veggie veggie fruit veggie veggie

Flowers and Fruits Guess the fruit that comes from these flowers…………………….. PUMPKIN

Guess the Fruit EGGPLANT

Guess the Fruit ZUCCHINI

Guess the Fruit PEPPERS

Guess the Fruit Tomato

Plant Responses and Growth Tropism- plant’s response to a stimulus Stimulus can be- Touch – Thigmotropism (Venus flytrap, climbing plants) Light- Phototropism- plants grow toward the light (sunflower) Gravity- Gravitropism- stems grow up and roots grow down

Thigmotropism in action tendril coiling