Use this as another study tool to help you narrow the focus of the notes down to the majority of what is going to be on the plant systems unit test. Keep in mind that memorizing just what is in this handout will not guarantee a 100! Happy studying! Characteristics of plants 1. Multicellular 2. Eukaryote 3. Cell Walls made of cellulose 4. Carry out the process of photosynthesis using Chlorophyll 5. Most are autotrophs but a few are parasites and saprobes. 6. Store energy as starch What do plants need to survive? 1. _Sunlight 2. _Water 3. Minerals 4. Gas Exchange 5. Transport of water and nutrients throughout the plant body Write the Equation for Photosynthesis Below: 6H2O + 6CO2 C6H12O6 + 6O2 How did Plants Evolve? Plants most likely evolved from an organism like the freshwater multicellular green algae living today. Plants had to overcome challenges as they moved from water to land : 1. Adapt to be able to acquire water 2. Adapt features to transport water 3. Be able to conserve water more efficiently. 4 Main Plant Groups 1. Bryophytes (Mosses and their 3. Seedless Vascular (Ferns and their relatives) relatives) 2. Seedless Vascular (Ferns and their 4. Seedless Vascular (Ferns and their relatives) relatives)
3 Classification Features 1. Water-conducting tissue (vascular) 2. seeds 3. flowers Vascular vs. Non-vascular Plants Vascular plants contain tube-like cells for transport. Can grow large and farther away from water source. Examples of vascular plants include MOSS, LIVERWORTS, & HORNWORTS. Non-vascular plants does not contain tube-like cells for transport. Water and nutrients travel in and out of cells by diffusion and osmosis. Small and grows close to source of water. PART 1: Bryophytes BRYOPHYTES Bryophyte - Non-vascular plants require moist environment. Plants draw up water by osmosis only a few centimeters above the ground. Low growing plants that are found in moist, shaded areas. Bryophytes include mosses, hornworts, and liverworts. Rhizoids- A long thin cell that anchors moss to the ground. Found in mosses and absorbs water and minerals from the soil. Draw an picture of a rhizoid in the box:
Uses of Moss Dead Moss can be burned as fuel or added to soil to help retain water and increase acidity of the soil. PART 2: Ferns and Gymnosperms Remember Vascular plants have vascular tissue. -Type of tissue specialized to conduct water. - Can grow larger and survive away from their water source. Vascular Structures Vascular Tissue is gathered into veins made of: 1. Xylem - Transports water and minerals throughout the plant. - When someone cuts an old tree down, they reveal a set of rings. Those rings are the remains of old xylem tissue, one ring for every year the tree was alive. 2. Phloem - Transport sugars produced by photosynthesis to the roots of the plant. -Dripping sap (sugars) coming from a tree is usually from the phloem. REMEMBER: Sap (sugar) Phloes out of the tree Vascular Plants Include: 1. Ferns (seedless) 2. Gymnosperms (cone bearing plants) 3. Angiosperms (flowering plants) Ferns Seedless vascular plants Require water for sperm to swim to egg. Seed Plants are Divided into Two Groups: 1. Gymnosperms -Bear their seeds directly on the surface of cones. 2. Angiosperms (Flowering Plants) -Bear their seeds within a layer of tissue that protects the seeds.
Gymnosperms Vascular plants Produce seeds on scales of cones Gymnospore means Naked Seeds Includes conifers such as pines and spruces. Advantages of Seeds 1. Seeds provide a food supply for the growing plant. 2. Protected by the seed coat. 3. Easily dispersed to new areas so not as much competition with parents. 4. Water isn t required for fertilization. - Female gametophyte develops inside the ovule. - Male gametophyte develops inside the pollen grain. Seeds in Gymnosperms Most gymnosperms produce seeds in woody cones Reproduction in gymnosperms takes place in cones. Conifers: The Largest Group of Gymnosperms Conifers Contain Needles to Help Reduce Water Loss By: 1. The shape of the needle results in reduced surface area. 2. Thick, waxy layer on the conifer reduces water loss 3. Openings of the leaves that allow for gas exchange are located in cavities below the surface of the leaf. Another Adaptation: Branches and needles are flexible so they don t break with the weight of the snow. Some Characteristics of Gymnosperms Most conifers are evergreens. They retain their leaves throughout the year. Most needles stay on the plant for 2-14 years. Can carry on photosynthesis as soon as spring arrives! A few are deciduous.
Deciduous - Lose their leaves at a particular season. Are dormant in the winter. Other Adaptations: 1. Some gymnosperms can grow tall because wood tubes (tracheids) that transport water and dissolved minerals. -Tracheids Key cells in the xylem that are connected end to end like a series of drink straws 2. Bark reduces water loss. PART 3: Angiosperms What are angiosperms? 1. Vascular plants. 2. Produce flowers. 3. Develop seeds in fruits which help protect embryos. Two Classes of Angiosperms 1. Monocots 2. Dicots Monocots: One seed leaf Includes: Grasses, Orchids, Lilies, and Palms Contains parallel veins in leaves Flower parts exist in multiples of three. Dicots Two seed leaves Most are flowering plants Includes: Shrubs, trees, wildflowers, garden flowers, herbs Leaves contain netted veins Flower parts exist in multiples of four or five
Flowers Monocots Dicots Floral parts often in Floral parts often in multiples of three multiples of 4 or 5 Leaves Parallel veins Branched veins Vascular Tissue Vascular bundles scattered throughout stem Vascular bundles arranged in a ring Root Pattern Fibrous roots Taproot Embryo in Seed Single cotyledon Two cotyledons Life Span of Angiosperms Can either be classified as: 1. Annuals 2. Perennials Annuals - Live only one growing season. Examples: Many garden plants (marigolds, petunias, pansies, and zinnias), wheat, and cucumbers. Perennials - Live for more than two years. Examples: Palm trees, sagebrush, maple trees, honeysuckles, asparagus, many grasses
General Vascular Tissue Terms Xylem - Tubes that carry water and minerals from the roots of plants to all of the cells. Phloem - Tubes that carry food from the leaves of the plants to all of the other cells. Cambium - growth tissue that makes new xylem and phloem Root Structures of Angiosperms Two Types of Root Structures: 1. Taproot System - Large central root and are usually found in dicots 2. Fibrous Root System - Highly branched and are usually found in monocots. More About Roots Root Hairs - Increase surface area for absorption (tiny little hairs). Root Cap - Covers the tip of the root and protects it. Meristem - Growth area just behind the root cap. Two Kinds of Stems: 1. Herbacous - flexible 2. Woody rigid - Have growth rings of vascular tissue that determine the age of the plant. More About Leaves Simple Leaves one leaf blade attached to stem Compound Leaves divided leaf blade attached to stem Petiole stalk that attaches leaf to stem
Cross Section of a Leaf The bulk of most leaves consist of a specialized ground tissue full of chloroplasts known as MESOPHYLL. The mesophyll contains two layers: 1. Palisade Layer closely packed tall columnar cells; located under the upper epidermis and absorb light that enters the leaf. 2. Spongy Layer loose tissue made of spherical cells that contains many air spaces between its cells; the air spaces connect with the exterior through the stomata (porelike openings that allow gases to enter and leave the leaf ). How Materials Move Through the Vascular Tissue As water is lost by transpiration (the evaporation of water from the leaves), it is pulled upwards through the xylem like a drinking straw. Sugars move by active transport and osmosis through the phloem from the source to the sink (place that stores or uses sugars). Release of water (transpiration) and gas exchange is controlled by stomata PART 4: REPRODUCTION OF FLOWERING PLANTS Flowers are reproductive organs that are composed of four kinds of specialized leaves: 1. petals 2. Sepals 3. stamens 4. Carpels (also called Pistils)
Petals Brightly colored structure just inside the sepals; attracts insects and other pollinators to a flower. Sepals Outermost circle of flower parts that encloses a bud before it opens and protects the flower while it is developing. Male Part of Flowers Stamen Male part of the flower; Made up of an anther and a filament. Anther produces pollen containing sperm. Filament supports the anther Female Part of Flowers Pistil (or Carpel) female part of a plant; Innermost part of a flower that produces the female gametophyte. Stigma- Sticky portion located at the top of the style where pollen frequently lands Broad base forms an ovary which contains one or more ovules (contains eggs inside). The diameter of the carpel narrows into a stalk called a style. A complete flower has all four organs, and an incomplete flower lacks one or more organs. Pollination Pollination Transfer of pollen from the stamen to the pistil. Methods of Pollination: 1. wind 2. animals (most are pollinated by animals)
Pollination Adaptations That Attract Animals: 1. Nectar 2. Petal Color 3. Scent 4. Types of Pollination Self-Pollination stigma receives pollen from the same plant Cross-Pollination Pollen from one plant is carried to the stigma of another plant - Must be the same type of plant - Allows for exchange of genetic material Reproduction of Flowers Reproduction in flowers is similar to gymnosperms in that both produce seeds and gametophytes are within the body of the sporophyte. Fertilization in Flowers 1. Pollen grain lands on the stigma 2. The pollen tube cell grows a tube to the ovule 3. The two sperm cells move through the tube into the ovule One sperm joins with the egg in the ovule. The other joins with the central cell (2N) to form the endosperm (3N) The process is called double fertilization Double Fertilization - Fertilization in angiosperms, in which two distinct fertilization events take place between the male and female gametophyte. Seed Formation 1. After fertilization occurs, the flower dies and the seed develops 2. Ovule becomes the seed coat which protects the embryo 3. The zygote divides becoming the embryo.
4. The 3N central cell develops into the endosperm which is food-storage tissue. Fruits The ovary develops into a fruit, which can be dry (nuts and grains) or fleshy (oranges, peaches, squash, or tomatoes). Fruits have two main jobs: To protect the seed and to aide in dispersal Seeds Seeds can remain dormant until conditions are right for development and growth. o -Water, oxygen, and favorable temperatures are usually needed. Germination Early plant stage of a plant embryo o Germination is the development of the seed into a new plant During growth, the roots appears first, and then the stem and finally the leaves Plant Growth and Development Plants respond to stimuli from the environment. This process is called tropism -Positive Tropism - Growth towards the stimulus. -Negative Tropism Growth away from the stimulus -Phototropism Growth towards light -Gravitropism Response to gravity -Thigmotropism- Response to response to touch PART 5: PLANT ADAPTATIONS Life in Water Have tissues with large air-filled spaces through which oxygen can diffuse down the stem Seeds that float and delay germination Specialized air roots that allow oxygen to get to the roots down in the mud Salty Conditions Specialized cells in the leaves that pump the salt out of the plant tissue onto the leaf surface where rain washes it off Desert Plants Root system- To reach far down to obtain water or shallow to obtain water Reduced leaves- Cactus needles reduced surface area Thick stems- To store water Dormant seeds- Germinate only when enough moisture present. Poor Soil
If the soil can t provide N2, plants trap and digest insects that release N2 Plant can be parasitic and extract nutrients and water directly from its host s tissues. Plants without Roots Live on body of another plant No roots = live in a humid environment to retain/store water from rainfall. Fighting Insects Make/secrete chemicals that are toxic if eaten Need for Pollination Plants will mimic a pollinators mate