General Biology for Non majors Plants and People Exam Study Guide Chapter 1 Introduction What makes something a plant o The combination of how it reproduces its structure and how it gets its nutrition and energy Plants are green because they contain chlorophyll They make food energy through the process of photosynthesis Plants don t move they have very rigid cell walls Plants have flowers seeds fruits spores ferns mosses or cones conifers as their mode of reproduction Organisms are named according to the binomial system genus and species o Ex Homo sapiens Organisms are classified on the basis of their evolutionary genetic relatedness The kingdom is the highest most all inclusive grouping of life o Kingdom phylum class order family genus species The five kingdoms of life are bacteria animals fungi protists and plants Bacteria were the first organisms to evolve Life first appeared on earth 3 5 billion years ago Photosynthesis evolved 3 billion years ago Multi cellular organisms evolved 1 5 billion years ago Green plants evolved 1 billion years ago Fungi evolved about 1 billion years ago Animals are more closely related to fungi than they are to plants Chapter 2 The Special Features of Plant Cells All living things are composed of cells The cell is the basic unit of life o Each cell is surrounded by a cell membrane Plant cells also have cell walls o Each cell contains a nucleus and cytoplasm Plant cells have all the components found in animal cells but in addition have a cell wall on the outside of the cell membrane and chloroplasts in the cytoplasm The chloroplasts are the site of photosynthesis The cell wall provides the plant with structural strength and rigidity Photosynthesis is the reaction that makes life possible It brings carbon into a form that can be used to make the molecules of our bodies and converts sunlight into an energy form that organisms can use o CO2 H20 Light Sugars 02 Photosynthesis Animals get their energy by digesting plant materials They break these materials down to CO2 and water through the process of respiration aka breathing o Sugars O2 CO2 H20 Energy Respiration The carbon cycle o Carbon enters the atmosphere as carbon dioxide from respiration and combustion burning o Carbon dioxide is absorbed by plants for photosynthesis The plants produce oxygen that humans need to breathe and serve as a source of food for animals o After animals feed on the plants they eventually exhale carbon dioxide through the process of respiration breathing o The animals and plants eventually die and the carbon that was in their bodies is returned to the atmosphere as carbon dioxide when they decompose o When decomposition is inhibited the dead plants and animals may eventually turn into fossil fuels which when burned also release carbon dioxide into the atmosphere Xylem and phloem are the plumbing of plants o Xylem transports water from the roots to the leaves and phloem transports sugars from the leaves to all the parts of the plant that are not photosynthetic roots interior parts of the stem fruits flowers The movement of water from the roots to the leaves and then out to the atmosphere is called transpiration Because plants lose lots of water through transpiration they must have a way to control the loss o Plants restrict water loss by having a waxy layer on the surface of the leaf and allowing CO2 uptake and water release only through special pores in the leaf surface called stomates Each stomate is surrounded by two guard cells that can swell or shrink to open the pore When the soil by the plant has lots of water the guard cells swell and open the stomates allowing CO2 into the leaf and water to escape When the soil is dry the guard cells shrink closing the stomate When this happens the plant loses much less water but it cannot take in CO2 so photosynthesis stops Cellulose is a molecule in the cell wall that provides plants with most of their strength It is composed of chains of sugars assembled into rods which are highly resistant to degradation It has the relative strength of steel on the plant s scale Chapter 3 How Plants Are Put Together root tips are Know where the shoot stem leaf petiole shoot tip lateral bud root and Growth in length is due to production of new cells in the shoot and root tips Plants that live more than one year perennials grown in width by means of cell divisions in the body of the stem and root These perennials grow mainly in width after they have reached a certain height The shoot tip makes the cells of the shoot as well as those of leaves lateral buds and flowers A flower is a modified shoot tip When flowering starts the shoot tip makes a flower instead of a lateral bud and growth stops The stamen is the male part of the plant and the pistil is the female part The stamen contains the anther and the filament stalk while the pistil contains the ovary stigma and style o Inside the ovary are one or more ovules and in each ovule is an egg The pollen grains which contain sperm form in the anther Pollen is carried from the anther to the stigma of the pistil The pollen grain germinates to form a tube which grows down the stigma and style into the ovary and then into the ovule It then fuses with the egg cell fertilizing it PLANT REPRODUCTION HAVE TWO PARTS POLLINATIO N IS THE TRANSFER OF POLLEN FROM THE ANTHER TO THE STIGMA FERTILIZATION IS THE FUSION OF THE SPERM AND EGG TO MAKE THE NEXT PLANT GENERATION FLOWERS ARE FOR POLLINATION AND FERTILIZATION FRUITS ARE FOR SEED DISPERSAL After fertilization the ovule grows and develops into the seed which contains a plant embryo Simultaneously the ovary enlarges and develops into fruit The endosperm provides the embryo with nutrients The cotyledons are modified leaves that also store nutrients for the embryo Chapter 4 Pollination and Seed Dispersal The function of the flower is to ensure that pollination occurs Wind pollinated flowers have small petals or no petals at all lots of pollen and large stigmas Animal pollinated flowers produce attractants colorful petals and scents and rewards sugary nectar and pollen Flowers that are pollinated by bees are blue or yellow in color and have sweet odors They also have broad open surfaces or petals large enough so that the bee can grab on Butterfly pollinated flowers are similar to those pollinated by bees Bees and butterflies are generalists meaning that they visit the flowers of many plants Plants that are pollinated by hummingbirds usually have odorless red
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