Plants

Characteristics of all plants Are producers and use photosynthesis to make their own food – Most are green because they contain the pigment chlorophyll Have eukaryotic cells – Have a true nucleus – Have cell walls

Have a cuticle – A waxy layer that covers the parts of a plant that are exposed to air like leaves and stems – Is an adaptation for living on land that keeps plants from drying out

Plant Classification 1) Non-vascular plants – Do not have tissues to transport water and nutrients – Depend on diffusion and osmosis to supply their cells with nutrients – Cannot grow very tall – Are usually found in moist places – Ex) mosses and liverworts

Moss Liverwort

2) Vascular plants – Have tube-like structures that transport water, minerals, and nutrients throughout the plant – Are divided into two groups Those that produce seeds – Divided into two groups: gymnosperms and angiosperms Those that do not produce seeds – Ex) ferns, club mosses and horsetails

PLANT CLASSIFICATION Non-vascularVascular SeedsNo Seeds GymnospermsAngiosperms

Examples

NON-VASCULAR PLANTS Rhizoids are thin, root-like structures. They anchor the plant. They aren't considered true roots, though, because they lack vascular tissue.

1.Contain a vascular system. 2.They grow in moist, shady habitats. 3.Has underground stems, roots, & large leaves called fronds. 4.Reproduce using spores, not seeds. The Fern - a seedless vascular plant There are 11,000 species of ferns.

fiddlehead frond

A structure that contains a plant embryo and a supply of food inside a protective covering Seed

Gymnosperms Group of vascular plants Do not produce flowers Their seeds are not enclosed by a fruit

1.Most common gymnosperms are Conifers 2.Conifers have leaves called needles or scales have a reduced surface area and thick waxy coat on the needle to reduce water loss and prevents freezing. Gymnosperms-Conifers Sequoia Juniper Pine

Conifer Reproduction 1.Male cones produce pollen and the female cone produces eggs and seeds. 2.Pollen is inefficiently transferred by the wind. 3.Once mature, the scales on the female cone dry out and open scattering the seeds by the wind. Pollen Pollen Cone Seed Cone

Angiosperms Known as flowering plants Produce seeds within a fruit Include fruit trees, roses, corn, grass and oak trees Are divided into two groups: monocots and dicots (based on number of cotyledons) – Cotyledon: an embryonic leaf inside the seed

Monocot characteristics

Dicot characteristics

Parts of The Plant

Functions of the Stem Transport water and nutrients from roots to leaves Supports leaves, fruit, and flowers Food storage

Leaves

Important Functions of Leaves Photosynthesis – Process that plants use to produce their food – 6CO 2 + 6H 2 O  C 6 H 12 O 6 + 6O 2 Transpiration – Loss of water and exchange of carbon dioxide

Leaf Parts Blade – Main body of leaf Petiole – Attaches blade to stem Midrib – Large central vein

Apex – Tip of leaf Base – Attaches to petiole – if petiole is absent, attaches directly to stem Margin – Edge of leaf

Epidermis – “Skin” of leaf - responsible for gas exchange Stomata – Outside layer of leaf opening in epidermis where gas and water exchange Mesophyll – Middle layer of leaf where photosynthesis occurs

Structure Wide Helps to catch more light energy Thin Help get carbon dioxide from bottom to top of leaf for photosynthesis

Leaf structure Greener on top CO 2 gets in here

Leaf diagram – palisade layer CO 2 Most chlorophyll

Leaf cell - palisade Position? Upper surface of leaf Features? Box shape Chloroplasts Function? Photosynthesis

Gas exchange Leaves are designed to allow carbon dioxide to get to the main chlorophyll layer at the top of the leaf They have small holes called stomata on the under surface Each hole is open & closed by 2 guard cells

Stoma position

Stoma is a small hole Its size is controlled by 2 guard cells closed open

Stoma function is for gas exchange in the leaf Carbon dioxide oxygen Guard cell Provided plant is photosynthesising

Stomata open and close at different times of the day When it is light the plant needs CO 2 for photosynthesis so the stoma open At night (darkness) they close

Gas exchange

Root Functions Absorption of water and nutrients – performed by root hairs Transportation of water and nutrients to stem Anchor plant to maintain stability Store food and water Roots have 4 primary functions

Parts of the Root Epidermis – Outermost layer of cells, like the skin of the root Cortex – Tissue inside epidermis that stores starch and other substances for the growth of the root

Root Types 2. Tap Roots – larger central root reaches deep water sources underground Ex. Trees, Carrots, & Dandelions 1. Fibrous Roots: branching roots hold soil in place to prevent soil erosion Ex. Grasses Tap Root

Can you identify these root types?

Parts of a flower

Flower Function Flowers are pollinated by: – Wind – Insects – Birds Sexual Reproduction!!!!

Flower Parts Pistil: female reproductive structure a.Stigma: sticky tip; traps pollen b.Style: slender tube; transports pollen from stigma to ovary c.Ovary: contains ovules; ovary develops into fruit d.Ovule: contains egg cell which develops into a seed when fertilized

Flower Parts Stamen: male reproductive structure a.Filament: thin stalk; supports anther b.Anther: knob-like structure; produces pollen c.Pollen: contains microscopic cells that become sperm cells

Reproductive Organs Close up of stigma, style and anthers in a tulip

Flower Parts Petals – Highly colored part of the flower, may contain perfume and/or nectar glands Sepals – Small green structures on the base of a flower that protect the flower bud

Parts of the flower

Fruit A ripened ovary that contains angiosperm seeds Function: to hold and protect the seeds Ex) corn, peach, tomato, pea, apple

Fruit can aid in dispersal of seed to reduce competition with parent plant. 1.Winged fruit – glides to new location (maple fruit) 2.Floating fruit – can float to new locations (coconut) 3.Fleshy fruit - sweet bright colored fruit have seeds that survive the digestive system of animals that eat the fruit (apple) 4.Spiny fruit- Velcro like projections attach to the fur of animals (cockleburs)

Maple seeds: Winged fruit Burdock: Spiny fruit

Bill Nye flowers video AoI0 AoI0

8L83LOy4k Bill Nye video on plants

Plant Tropisms Tropism: the way a plant grows in response to stimuli in the environment. a. Phototropism: growth response to light -Plants bend towards light

b. Geotrophism: growth response to gravity -plant roots grow down with gravity, shoots (stems) grow up against gravity and out of the soil. c. Thigmotropism: growth response to touch -vines grow up around trees, venus flytrap closes when leaves are touched

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Geotropism What type of tropism is shown in these pictures? Thigmotrophism Geotropism Phototropism