Plant Structures, Reproduction, and Responses

2 Types of Plants BRYOPHYTES BRYOPHYTES Mosses, liverworts, hornworts Mosses, liverworts, hornworts NO tissue to transport water and nutrients NO tissue to transport water and nutrients NON Vascular NON Vascular TRACHEOPHYTES Vascular plants Have tissue for transporting water and nutrients

Vascular Tissue The function of vascular tissue is to transport water and nutrients between roots, stems, and leaves Stem Cross-Section

Xylem transports water from the roots to the leaves

Phloem transports sugars from the leaves to the roots

Plant Organs The three principle organs of plants are: Roots Roots Stems Stems Leaves Leaves

Root Functions Functions of roots: Anchor the plant to the ground Anchor the plant to the ground Absorb water and minerals Absorb water and minerals Store sugars or starches Store sugars or starches

Root Structures Taproot – long, thick root that is the main root of the plant Taproot – long, thick root that is the main root of the plant Fibrous roots – many, smaller branching roots Fibrous roots – many, smaller branching roots

Stem Function Functions of stems: Growth of the plant, including production of leaves, branches, and flowers Growth of the plant, including production of leaves, branches, and flowers Support – stems hold leaves up to the light Support – stems hold leaves up to the light Transport of water and sugars between the roots and leaves Transport of water and sugars between the roots and leaves

Leaf Functions Photosynthesis – plant cells use sunlight to convert carbon dioxide and water into sugars Photosynthesis – plant cells use sunlight to convert carbon dioxide and water into sugars 6 CO H 2 O + light  C 6 H 12 O O 2 Transpiration – water is pulled from the roots and stems of the plant as it evaporates from the surface of the leaves Transpiration – water is pulled from the roots and stems of the plant as it evaporates from the surface of the leaves Gas exchange – leaves take in carbon dioxide for photosynthesis and release oxygen and water vapor into the air Gas exchange – leaves take in carbon dioxide for photosynthesis and release oxygen and water vapor into the air

Parts of a Leaf The blade is the flat part of the leaf that catches sun The blade is the flat part of the leaf that catches sun The petiole is the thin stalk that attaches the leaf to the stem The petiole is the thin stalk that attaches the leaf to the stem

Structures of Leaves Stomata / Stoma Stomata / Stoma Pores on the undersides of leaves Pores on the undersides of leaves Control transpiration rate and allow gas exchange Control transpiration rate and allow gas exchange Guard cells are specialized cells that control the opening and closing of the stomata Guard cells are specialized cells that control the opening and closing of the stomata

Modified Leaves Tendrils Succulent Storage Leaves Spines Bracts

Flowers are leaves that are modified for sexual reproduction draw and label flower in your journal

Angiosperms Flowering plants Flowering plants Produce seeds inside fruit Produce seeds inside fruit

Types of Flowering Plants Monocots Monocots Contain one seed leaf Contain one seed leaf D icots Contain TWO seed leaves

Cotyledon (seed leaf) Monocots versus Dicots One cotyledon (seed leaf) Two cotyledons (seed leaves)

Conifers Plants that produce seeds in cones Plants that produce seeds in cones No fruit = “Naked seed” No fruit = “Naked seed”

Pistil - Female Reproductive Structure  stigma receives the pollen from the anther  pollen grows a tube down through the style  ovary produces females gamete and protects developing seed

Stamen - Male Reproductive Structure  anther produces pollen  pollen - male gamete, powder  filament is a stalk that supports the anther

Pollination The transfer of pollen from a stamen to a pistil

Methods of Pollination Wind Wind Water Water Gravity Gravity Insects/animals Insects/animals

Fertilization 1.Pollen lands on stigma 2.Travels down style 3.Joins with ovule 4.Ovary becomes fruit 5.Seeds develop inside fruit The union of the pollen and ovule

Tropisms in Plants A plants’ growth in a certain direction in response to a stimuli A plants’ growth in a certain direction in response to a stimuli Phototropism - growth towards light Phototropism - growth towards light Geotropism – response to gravity Geotropism – response to gravity Roots toward gravity (+) Roots toward gravity (+) Stems and leaves away from gravity (-) Stems and leaves away from gravity (-) Hydrotropism – growth towards water Hydrotropism – growth towards water Thigmotropism – response to TOUCH! Thigmotropism – response to TOUCH!

Plant Hormones Auxins – hormones that control growth and cell elongation in response to phototropism, inhibit lateral growth Auxins – hormones that control growth and cell elongation in response to phototropism, inhibit lateral growth Gibberellins – hormones that control plant height and bud development; stimulate seed germination Gibberellins – hormones that control plant height and bud development; stimulate seed germination Abscisic Acid – hormone that slows or stops growth and cell division in plants Abscisic Acid – hormone that slows or stops growth and cell division in plants