The World of Plants KINGDOM PLANTAE

What is a Plant: Plant Characteristics EUKARYOTIC – has a nucleus MULTICELLULAR– more than one cell AUTOTROPHIC – can make their own food, although some can be heterotrophic (i.e. Venus Fly Trap). SESSILE - remains stationary CELL WALLS made of cellulose

WHAT DO PLANTS NEED TO SURVIVE? Sunlight – carry out photosynthesis Water & Minerals – Needed to grow Gas Exchange (CO 2 – H 2 O) – Carry out cellular respiration Movement of Water & Nutrients – to transport food and water from roots to leaves and leaves to roots.

Plants have Organs: Leaves – gather sunlight to carry out photosynthesis Stems – support the leaves and flowers Roots – anchor plants to the soil Flowers – carry out reproduction Vascular Tissue: - Xylem: transport water & minerals from the roots. - Phloem: transport food (sugar/glucose) from the leaves to the rest of the plant

Cuticle Upper epidermis Mesophyll Bundle sheathVascular tissue - Xylem - Phloem Guard cells chloroplast stoma LEAF STRUCTURE

CUTICLE: waxy waterproof layer that coats the outer parts to help prevent evaporation of moisture. MESOPHYLL: the middle part of the leaf where most of photosynthesis is carried out. STOMATA: pore-like openings that allow CO 2 and O 2 to diffuse in and out of the leaf. GUARD CELLS: specialized cells that control the opening and closing of the stomata by responding to changes in water pressure.

LEAF ADAPTATIONS CHANGES IN STRUCTURE OR FORM THAT ALLOW FOR BETTER SURVIVAL IN SPECIFIC ENVIRONMENTS PINE NEEDLES (REDUCES WATER LOSS) CACTUS NEEDLES TO PROTECT THEMSELVES FROM HERBIVORES

8 Plants are divided into two groups based on whether they contain vascular tissue. Vascular Bundles Taxonomy of Plants

9 Nonvascular Plants Bryophytes do not have vascular tissue. They depend on water for reproduction so they live very close to the ground where water is in regular supply. Moss

10 Tracheophytes: contain vascular tissue They also contain seeds. Club Moss

11 Seed-Producing Vascular Plants Includes two groups – Gymnosperms and Angiosperms Gymnosperms bears seeds on the surface of cones. Angiosperms bear seeds within a protective layer (fruit).

GYMNOSPERMS (means “naked seed”) most common group is the conifers Examples: fir, spruce pine.

13Gymnosperms Contains the oldest living plant – Bristle cone pine or redwood Contains the tallest living plant – Sequoia or redwood

CONIFERS: OLDEST SURVIVING TYPE OF SEED PLANTS. PRODUCE MALE AND FEMALE CONES. FEMALE CONE IS WHERE POLLINATION BEGINS MALE CONE PRODUCES POLLEN GRAINS

ANGIOSPERMS (“seeds encased in fruit) flower bearing plants

16Angiosperms Flowering plants Seeds are formed when an egg or ovule is fertilized by pollen in the ovary Ovary is within a flower Flower contains the male (stamen) and/or female (ovaries) parts of the plant Fruits are frequently produced from these ripened ovaries (help disperse seeds)

17Angiosperms Subdivided into two groups – Monocots and Dicots Monocots have a single seed cotyledon Dicots have two seed cotyledons

18Monocots Parallel venation in leaves Flower parts in multiples of 3 Vascular tissue scattered in cross section of stem

19Dicots Net venation in leaves Flower parts in multiples of 4 or 5 Vascular tissue in rings in cross section of stem

Dicots: Seeds that have two cotyledons (inc. peas, tomatoes, roses, daisies, etc.)

FLOWERS The reproductive organ of a flowering plant FUNCTION - produce male (sperm) and female (egg) gametes & provide a structure for fertilization. Designed to attract specific pollinators.

PARTS OF A FLOWER Petals Pistil: Stigma Style Ovary Stamen: Anther Filament Sepals

STEMS

1.Support leaves & flowers 2. Transport water and nutrients throughout the plant. 3. Some are adapted to store food & remain dormant during inclement weather STEMS: MAIN FUNCTIONS

2 TYPES OF ROOTS: 1. Anchor plants 2. Absorb water & minerals

TAP ROOTS ABLE TO REACH WATER FAR BELOW THE SURFACE

FIBROUS ROOTS PREVENT THE EROSION OF TOP SOIL FROM HEAVY RAINS.

28 Why We Can’t do Without Plants! Produce oxygen for the atmosphere Produce lumber for building Provide homes and food for many organisms Prevent erosion Used for food

29 More Reasons We Can’t do Without Plants! Produce wood pulp for paper products Source of many medicines Ornamental and shade for yards Fibers such as cotton for fabric Dyes