Structure and Function Adaptations Plants Structure and Function Adaptations

The Plant Cell- review Are plants autotrophic or heterotrophic? Autotrophic (remember, plants are producers and they make their own food via photosynthesis) Are plants prokaryotic or eukaryotic? Eukaryotic (remember, eukaryotes have nuclei just like we do and YOU are EUkaryotes) Are plants multicellular or unicellular? Multicellular! Plant cell walls are made of…. Cellulose

The Plant Cell: Label!

Nonvascular vs. Vascular Nonvascular plants do not have a system for transporting water and other nutrients within their body Nonvascular plants are small and lack vascular tissue (roots, stems and leaves). Mosses, liverworts, and hornworts are nonvascular plants.

Nonvascular vs. Vascular Vascular plants are plants that contain structures with vascular tissue (roots, stems and leaves) Seedless plants Seed plants Gymnosperms and Angiosperms Vascular plants are composed of: Tissue Roots Leaves Stems Each plant part – tissue, root, stem, leaf - has a specific role in keeping the plant alive through photosynthesis

Vascular Plants Seedless Vascular Plants: Reproduce with spores Seedless vascular plants produce spores with thickened walls that prevent them from drying out. Examples: Ferns, club mosses, horsetails, and whisk ferns are seedless vascular plants. Reproduce with spores - diagram shows spores growing in clusters called sori on the back of the fern http://en.wikipedia.org/wiki/Image:Lycopodium_plant.jpg

Structures of Vascular Plants Seed- adaptation to terrestrial life composed of a plant embryo, stores food and contains a protective coat Cone- reproductive structure of gymnosperms; contains pollen in males and ovules in females Ovulate cone- from a pinetree (female) Staminate cone- from a pinetree (male) Flower- reproductive structure of angisperms composed of 4 sets of modified leaves Fruit- mature ovary of a flower that protects dormant seeds and aids in their dispersal Cotyledons – nonphotosynthetic leaves of an immature plant; provide source of nutrients until plant can produce its own food

Vascular Plants Vascular Plants that produce seeds: Gymnosperms Produce cones Conifers, cycads, ginkgoes, and gnetophytes Angiosperms Fruits or flowers The angiosperms are classified as either monocots or dicots.

Angiosperms Monocot vs. Dicot Monocots: Dicots: Two cotyledon One cotyledon Veins parallel Vascular bundles in complex arrangement Fibrous root system Floral parts in multiples of three Ex. Iridaceae (irises), Liliaceae(lilies) and Poaceae (grass). Dicots: Two cotyledon Veins netlike Vascular bundles arranged in ring Taproot usually present Floral parts in four or five Ex. Asteraceae (composite), Brassicaceae (mustard), Fabaceae (legume), and Rosaceae (rose),

Tissues, Roots, Leaves, Stems A vascular plant’s body contains three kinds of tissues—dermal tissue, ground tissue, and vascular tissue. 1.Dermal Tissue Dermal tissue covers a plant. A thin layer of epidermis covers nonwoody parts. Several layers of cork cover woody parts. 2.Ground Tissue Ground tissue is specialized for photosynthesis in leaves and for storage and support in stems and roots. 3.Vascular Tissues Vascular tissue conducts water, minerals, and organic compounds throughout the plant. Xylem (carries reactants) vs. phloem (carries products)

Vascular – refers to an internal system of tubes or vessels to transport materials throughout the plant - xylem – transports water and minerals up from the roots to the shoots - phloem – transports sugar (food) down from the leaves to the rest of the plant Translocation Organic compounds are pushed through the phloem from a source to a sink in a process called translocation. Transpiration Transpiration, the loss of water from a plant’s leaves, creates a pull that draws water up through xylem from roots to leaves.

Roots Function- absorption, storage and anchorage Roots have a central core of vascular tissue that is surrounded by ground tissue and epidermal tissue. Root hairs on root tips increase the surface area which increases absorption Remember that Nitrogen Fixation happens in the roots! (Nitrogen fixation is when nitrogen in the atmosphere is converted by bacteria into nitrogen compounds like ammonia, nitrates and nitrites)

Stems Function: support and transfer Contain the Xylem and Phloem Help define plant types (shrubs, vines, trees, etc)

Leaves Site of photosynthesis composed of blade, veins, petiole Simple leaf shapes Entire leaf Palmate (heart shaped) Palmately lobed Pinnately lobed Compound leaf shapes Singly compound leaf Palmately compound leaf Doubly compound leaf Leaves Site of photosynthesis composed of blade, veins, petiole simple or compound

There are different layers of leaves epidermis – adaptation for terrestrial life- covering of leaf waxy cuticle - coats upper and lower epidermis stomata – site of transpiration Guard cells- control water loss by closing a plant’s stomata when water is scarce

See pg. 559 – Yes, you need to know the layers of leaves

Plant Adaptations Absorbing Nutrients To survive on land, plants evolved the ability to absorb mineral nutrients from the soil. Preventing Water Loss To survive on land, plants evolved a waxy outer covering called a cuticle, and stomata and guard cells for gas exchange, to prevent their bodies from drying out. Reproducing on Land To survive on land, plants use pollen to reproduce without water and transmit male gametes.

Vascular Plant Adaptations Advantages of Conducting Tissue Vascular plants have a system of well-developed tissues that transport water within a plant. Advantages of Seeds Seeds protect and nourish a plant’s embryo, disperse the offspring, and delay the growth of the embryo until conditions are favorable. Advantages of Flowers Flowers make reproduction more efficient by promoting pollination.

Plants in our Lives Fruits and Vegetables Root Crops Legumes Wheat All types of plant parts—roots, stems, leaves, flowers, fruits, and seeds—provide food for humans. Root Crops Root crops, such as potatoes, grow underground. Legumes Legumes, such as peas, produce protein-rich seeds in long pods. Wheat For more than one-third of the world’s population, wheat is the primary source of food. Corn Corn is the most widely cultivated crop in the United States. Rice For more than half of the people in the world, rice is the main part of every meal.

Plants in Our Lives Wood Medicines Fibers Wood is a source of wood pulp used for making paper, lumber used for building materials, and fuel. Medicines Many important medicines are currently made from plants or were originally derived from plants. Fibers Plant fibers are used to make paper, cloth, and rope. The most important sources of plant fibers are wood and cotton.

Fruit or Veggie? A fruit is the ripened ovary and contains seeds. Therefore, tomatoes, peppers, squash, olives, and cucumbers are FRUITS, not vegetables.

Vascular Plants (Tracheophytes) Nonvascular Plants (Bryophytes) - spores Seedless Plants - spores Seed Plants Mosses Liverworts Hornworts 26,000 species Conifers (Gymnosperm) 600 species Flowering Plants (Angiosperm) 260,000 species Ferns 12,000 species Monocot 60,000 species Most grains Dicot 200,000 species Most flowering plants