Transcript Plants
Slide 1 Structure of Plants & Reproduction What do plants need to grow? Space Temperature Sunlight Water Nutrients (N, P, K) Air (CO2) Time Plants 1. Photosynthesis – process that provides energy for almost all life occurs in chloroplasts. Know the chemical equation. 6CO2 + 6H2O Carbon dioxide + Water Light C6H12O6 + 6O2 Glucose Oxygen Plants 2. Chloroplasts – organelles that use light energy to make carbohydrates from carbon dioxide and water through the process of photosynthesis. Plants 3. Cell wall – surrounds plant cell provides support and protects from damage made of protein and carbohydrates, like cellulose. Plants 4. Central vacuole – stores water and may contain ions, nutrients, and wastes. Makes the plant cell rigid and stand upright. (page 66) Plants 5. Glucose – a single sugar (monosaccharide) made through photosynthesis light 6CO2 + 6H2O C6H12O6 + 6O2 Carbon dioxide + Water Glucose Oxygen Kinds of Plants Nonvascular Plants – Small – Lack vascular tissue – Examples = moss, liverworts and hornworts • t Moss Liverworts Vascular Plants – Has tissue that moves food and nutrients around plant – leaves, stems, and roots – produces food for plant only in leaves Plant Tissue Systems •3 types of plant tissues 1) Dermal tissue 2) Vascular tissue 3) Ground tissue Dermal tissue •Epidermis – Single layer of cells that make up outer covering of plants •Cuticle – Thick, waxy coating that protects against water loss and injury – Found on most fruits, stems & leaves Cuticle and Stoma Cuticle Cross Section Stoma Vascular Tissue • Transport system; moves water & nutrients throughout plant – Xylem •Carries water upward from roots to plant structures – Phloem •Transports nutrients & carbohydrates produced by photosynthesis Plants Xylem – vascular tissue of plants that transport water and minerals. Xylem zips up! Plants Phloem – vascular tissue of plants that transport organic nutrients. Phloem = food down. Plants Stomata – (singular stoma) pores that exchange oxygen and carbon dioxide. Closed Plants Guard cells – specialized cells that border stoma. Closes & opens pores for gas exchange. Ground Tissue •Cells between dermal and vascular tissues •3 types of cells make up ground tissue 1) Parenchyma cells 2) Collenchyma cells 3) Sclerenchyma cells Plant Structure •Major organ systems •Roots •Stems •Leaves Plants Shoot (stem) – structure that grows upward. Shoot also called the stem 1. Supports plant 2. Holds leaves/ branches upright 3. Houses transport system that carries water & nutrients through tissues Plants Root – structure that grows downward. Root Roots 1. 2. 3. Anchor & support Absorbs water & minerals through tissues Hold soil in place Root Hairs Fibrous Roots Functions of Leaves 1. Photosynthesis 2. Broad, flat surface increases surface area for light absorption 3. Have systems to prevent water loss • Stomata • cuticle on surface 4. Gas exchange • Allow CO2 in and O2 out of leaf Elephant Ear Plant Transpiration 1. Transpiration: loss of excess water from plant leaves 2. Significance: a. Transpiration causes enough pressure to help pull water (& required nutrients) up stem from roots. b. As part of the water cycle, trees transpire water back into the atmosphere. c. Transpiration provides much of the daily rain in rainforest. A B A average size maple tree can transpire 200 liters of water per hour during the summer. Transpiration is the #1 driving force for pulling water up stems from roots. Kinds of Plants Gymnosperms Angiosperms – Seed plants that produce cones – Ex. Pine trees, giant sequias, douglas firs, and ginkgo tree – Seed plants that produce fruit and flowers. – Ex. Sunflowers, apple trees, and grass Sunflowers Spores on the underside of fern leaves. Grass The unique fan-like leaves of the ginkgo tree Angiosperms – 2 Types 1. Monocot – Produces seeds with one seed leaf (cotyledon) 2. Dicot – Produces seeds with two seed leaves (cotyledon) Plant Reproduction Plants Vegetative propagation – asexual reproduction of plants from a modified stem, root, or leaf. Plants Pollination – transfer of male reproductive structures (pollen) of a plant to the female reproductive structures (ovules) of a plant. • Fertilization: union of male and female gametes to form a zygote. Plants 16. Germination – seed breaks from dormancy (inactivity) and embryo resumes development. Life Cycle of a Gymnosperm Tree produces male and female cones. Male pollen scattered by wind and fertilizes female ovule when trapped by sticky substance. Wind disperses pine seeds Seed grows into seedling tree Life Cycle of an Angiosperm • Pollen grains produced by anther land on stigma • Pollen tube grows into ovule • Sperm cell moves through tube and fertilizes the egg. • Ovule develops into seed with the seed’s embryo inside. • The ovary develops into a fruit. • Seeds are dispersed and grow into a new plant. What is the purpose of flowers for plants? A. Function of a Flower 1. Attract pollinators2. Site of sexual such as insects, reproduction birds, and bats 3. Forms fruit that o Brightly colored will carry seeds (embryos) o Fragrant o Produce nectar Slide # 12 B. Structure of a Flower 1.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: egg; develops into seed when fertilized Slide # 13 Female Reproductive Leaf B. Structure of a Flower 2.Stamen: male reproductive structure a.Anther: knob-like structure; produces pollen b.Filament: thin stalk; supports anther c.Pollen: contains microscopic cells that become sperm cells Slide # 15 Male Reproductive Leaf Contains Pollen B. Structure of a Flower 3.Sepal: encloses & protects flower before blooms (sepals=calyx) 4.Petals: usually colorful & scented; attracts pollinators Slide # 17 C. Cross Pollination • How does pollination happen? – Pollen from different anther fertilizes ovary on another flower. • What is the result of pollination? • A Fruit: An ovary containing seeds. • Seed - protect embryo from damage and water loss; dispersed away from parent plant E. Types of Seed dispersal What is seed dispersal? Method for seeds to spread away for parents. Why is seed dispersal important? • Reduces competition (parents) • Increases chance for survival Seed Dispersal • Wind – Flight • Water – Flotation • Animal – Fruits – Burrs Can you identify the type of seed dispersal that may be used by these plants? WIND WATER WIND Flower Dissection Lab • Groups of 4 • Have one person in group get materials. • Each person will do worksheet. • Read directions on lab procedure. • If have questions, make sure answer is not in lab procedures or other group members do not know before asking teacher. • Look at Ch. 23 and 24 for reference. – Pg 538