Transcript PPT #2
Plants Structures and Reproduction Warm - Up List all the parts of a plant that you can eat and what name do we give them? Ex. Leaves – “lettuce” We Eat… ROOTS Carrots Radishes Onions Horse raddish STEMS LEAVES Celery Potatoes Lettuce FLOWER PARTS Apples Strawberries Peaches Seeds asparagus 8-1 What are Roots? Most roots grow underground Important functions: Anchor (hold) plants firmly in the soil Take in water Absorb minerals Store food for the plant Types of Roots Two Types: 1. Fibrous Root Systems • Made up of many thin, branched roots 2. Taproot System • Made up of one large root & many small thin roots Root Structure Tube-like structure 3 layers 1. Epidermis with Root hairs (outermost) 2. Cortex (soft, stores food) 3. Transport Tubes (innermost) • Carries water & minerals up to plant Root Cap Protects root as it pushes down through soil New cell growth Root Hairs Increase surface area…helps the root absorb the max. amount of water and minerals WARM-UP Draw, Name and Describe the three layers of a root in order from the outermost to the center. 8-2 What are Stems? 2 Types of Stems: Herbaceous stems Soft and green stems Usually shorter plants (<2m tall) Plants with these stems die yearly Wood Stems Rough, sturdy Outer layer is “bark” in trees Plants with these stems live a long time Functions of Stems Support Leaves Transport water and minerals up from the roots to the leaves. Store food (ex. sugarcane) Protection Bark of tree trunks – dead cells Stem Structure Contains Transport Tubes to carry materials! Phloem Carries food made in leaves down to tree. Xylem Carries H2O up to leaves Stem Structure (cont.) Cross-Sectional View of a Stem Vascular Transport Tubes Warm-Up Do all leaves come in the same shapes and sizes? Sketch as many different types/shapes of leaves you can come up with! 8-3 What are Leaves? Location of most photosynthesis on a plant Vein Structure: Blade – wide, flat part of a leaf Stalk – supports the blade Vein – bundle of vascular tubes that contain the xylem and phloem in a leaf. Stalk Blade Kinds of Leaves Simple Leaves – all in “one” piece Compound Leaves – divided into many pieces (little leaves) Leaflet Simple Compound Leaf Tissues Epidermis outer protective layer of the leaf Prevents water loss (evaporation) with “waxy” coat called “Cuticle” Epidermis Vein Leaf Tissues (cont.) Stoma (pl. stomata) tiny openings in on the top and bottom surface of leaves for gas exchange Oxygen and Carbon Dioxide gases stoma Leaf Tissues (cont.) Mesophyll Middle tissue layer in a leaf Site of photosynthesis! These cells have the chloroplasts with green chlorophyll in them! Mesophyll The Big Picture! Stoma Stalk/Petiole Veins Epidermis Xylem Mesophyll Blade Phloem WARM-UP Label the following leaf structures 8-4 What is Photosynthesis? Autotroph Heterotroph Organism that makes Organism that cannot its own food. make its own food. •Plants are _________________________. •Plants undergo a “food making process” called ________________. •Food making cannot occur without the pigment _________________ which is found in the ________________. •Pigments are what “capture” light for photosynthesis! Demo…removing chlorophyll 1. 2. 3. 4. 5. Shred spinach leaves Pour isopropyl alcohol Press on leaves Pour off resulting liquid Observe its color! Take a Moment to write out the equation for Photosynthesis! Hints: 1. 2. 3. 4. What gas do plants give off that we breath? What liquid material do all organisms need? What gas do plants take in from the atmosphere? What is the reason plants go through photosynthesis? ________ + ________ ---- ________ = ________ Photosynthesis (equation) CO2 + H20 + C6H12O6 + O2 Carbon dioxide + water + sunlight energy sugar + oxygen Steps of Photosynthesis Put the following steps in the correct order on your flowchart. DRAW & COLOR a picture demonstrating each step in the box provided. Sunlight energy is used to make glucose (C6H12O6) Phloem carries the glucose down to the plant. Carbon Dioxide enters the leaf through stomata Correct Order… 1. Roots absorb water and minerals from soil 2. Xylem carries water up stem and into leaves. 3. Carbon Dioxide enters the leaf through stomata 4. Sunlight energy is used to make glucose (C6H12O6) 5. Phloem carries the glucose down to the plant. Flowers & Their Structures Objectives Identify that the flower is the reproductive organ of a plant Describe the parts of a flower Flower Parts Sepal – special type of leaf that protects the flower bud Petal – brightly colored structure above the sepal Pistil – female reproductive organ in a flower (contains ovules) Stamen – male reproductive organ in a flower (makes pollen) Closer Look at Reproductive Organs! Pistil Stigma (sticky for catching pollen) Style Ovary (becomes fruit after fertilization) Ovule (becomes embryo/seed after fertilization) Pollen Tube carries pollen/sperm down to the ovules Stamen Anther (makes pollen) Filament (support for anther) ovary Perfect vs. Imperfect Flower Perfect Flower with BOTH male and female reproductive organs Imperfect Flower with either male OR female (but not both) reproductive organs What advantage do you think “Perfect” flowers have in the survival of their species?? Warm-Up Flower Reproduction Pollen grains (male reproductive sex cell …aka SPERM) are released when anthers burst open Pollination occurs when the pollen travels from the stamen to the pistil Pollen attaches to the stigma of the pistil (female) and travels down the pollen tube to the ovules. Fertilization occurs when the male (pollen) and female cell (ovule) nuclei join. After Fertilization… The ovules (found inside the ovary) turns into SEEDS. Each seed contains a young embryo (or undeveloped plant) inside it. While seeds are forming, the ovary transforms into a large, fleshy fruit around them. Examples – watermelons, apples, tomatoes Cross Pollination Pollen from one flower travels to the pistil of another flower by means of wind, insects, or animals. Self Pollination Anther from a plant drops pollen grains onto the stigma of the same plant. Cross vs. Self Pollination Overview Self Pollination Cross Pollination Plant Reproduction (asexual) Vegetative Propagation Parts of plants (stems) can grow into entirely new plants Tubers Underground stem that can grow into an identical plant Bulbs Leaf-covered underground stem that grow into plants (daffodils & tulips) Cuttings Plants can grow from pieces of themselves (ex. Leaves or branches) WARM-UP (write on note paper) Put into the correct order… Pollen (sperm) travels down pollen tube to ovule Wind carries pollen in the air A seed is produced inside ovary Pollen is “grabbed” by a sticky stigma Fertilization occurs Protective fruit is formed around seed Warm-Up Answers 1. 2. 3. 4. 5. 6. Wind carries pollen in the air Pollen is “grabbed” by a sticky stigma Pollen (sperm) travels down pollen tube to ovule Fertilization occurs A seed is produced inside ovary Protective fruit is formed around seed 8-8 SEEDS Seeds contain: A seed coat A developing embryo “leaves” that store food (cotyledons) Endosperm “food” in monocots Each Embryo has a : Mini root (radicle) Mini stem (Hypocotyl) Mini leaves (epicotyl) SEEDS (cont.) Seeds are covered in a hard protective outer covering called a SEED COAT A “scar” or HILIUM can be seen on the outside of seeds. Location where pollen tube attached to ovule Dispersal and Germination Seeds can disperse (spread out) with help of the wind and animals Ex. Dandelion, burs, bird feces When enough water seeps into a seed, the embryo can germinate and start growing. “April Showers Bring May Flowers” Discovering Seed Anatomy The seed you will be observing is a LIMA BEAN (yes a bean is a seed) 1. 2. 3. Obtain a seed from your teacher Follow the procedure Sketch appropriate structures WARM-UP Write down 3 stimuli as well as the 3 responses they cause. Example: Loud screams you cover your ears STIMULUS RESPONSE Plant Responses Plants respond to stimuli from the environment (ex. touch, light, water, gravity) Stimulus – Change that causes a response A change in a plant’s growth that is caused by a response to a stimulus is called a tropism. tropisms overview Tropisms Phototropism A plants response to light Plants grow towards light Tropisms Gravitropism A plant’s response to gravity Stems grow up, roots grow down Tropisms Hydrotropism A plant’s response to water Plant roots grow towards water Tropisms Thigmotropism A plant’s response to touch Ex. Climbing vines, mimosas, sundews Mimosa Pudica Video Sundew video