Ch 1 Characteristics of green plants o Green because they contain chlorophyll to trap sunlight for photosynthesis o Photosynthesis is the process by which plants gain carbon and energy for growth and they use the energy of sunlight to convert carbon dioxide from the atmosphere into sugars o Plants are structural each plant cell is surrounded by a rigid cell wall o Method of plant reproduction is different than other organisms they make flowers fruits and seeds or spores Organisms are named according to the binomial system o Carl Linnaeus initiated the use of a two word name genus and species to identify each type of organism He then classified them into kingdom phylum class order family genus species Now biologists classify organisms on the basis of their evolutionary genetic Kingdom classification is the highest most inclusive general grouping of o Bacteria animals fungi protests and plants Bacteria were the first organisms to evolve o First organisms appeared 3 5 Billion years ago o 3 billion years ago some bacteria had evolved photosynthesis o Multicellular organisms evolved from bacteria about 1 5 billion years o around 1 billion years ago plants fungi and animals evolved o green land plants first organisms to colonize dry land evolved about 1 billion years ago o animals are more closely related to fungi than they are to plants Flowering plants and angiosperms are the youngest and most abundant plant group o Most diverse abundant and important group in the green plant relatedness life ago kingdom Ch 2 All living things are composed of cells o Cells are the basic unit of life o Each cell is surrounded by a cell membrane o Each cell contains a nucleus and cytoplasm Plant cells have all the components of animal cells but they also have a cell wall on the outside of the cell membrane as well as chloroplasts where photosynthesis takes place in the cytoplasm The cell wall provides the plant with structural strength and rigidity Chemical reaction of photosynthesis CO2 H2O LIGHT Sugars O2 o This is the reaction that makes life possible because this is the source of oxygen that we breathe Also this reaction brings carbon into a form that can be used to make the molecules of our bodies and it converts sunlight into an energy form that organisms can use Respiration is the reverse chemical reaction of photosynthesis Carbon cycle o 1 Carbon enters the atmosphere as carbon dioxide from respiration breathing and combustion burning o 2 carbon dioxide is absorbed by producers plants to make carbohydrates in photosynthesis These producers then put off oxygen o 3 Animals feed on the plants Thus passing the carbon compounds along the food chain Most of the carbon these animals consume however is exhaled as carbon dioxide This is through the process of respiration The animals and plants then eventually die o 4 The dead organisms dead animals and plants are eaten by decomposers in the ground The carbon that was in their bodies is then returned to the atmosphere as carbon dioxide In some circumstances the process of decomposition is prevented The decomposed plants and animals may then be available as fossil fuel in the future for combustion Animals get their carbon by eating plants and get their energy by digesting plant materials breaking them down to CO2 water through respiration Xylem moves water from roots to leaves Phloem moves sugars from leaves to roots Transpiration the movement of water from the roots to the leaves and then out to the atmosphere o Plants can loose a lot of water through this process therefore they must be able to control the water loss when the soil is dry Stomates CO2 uptake and water release takes place through these special pores in the leaf surface Guard cells stomates are surrounded by a pair of these special cells that can swell or shrink to open or close the pore o When soil has plenty of water the guard cells swell and open the stomates allowing CO2 in the leaf and water to escape o When soil is dry the guard cells shrink closing the stomates Allows plant to lose less water but also prevents plant from absorbing CO2 therefore photosynthesis stops Cellulose molecule in cell walls that provides most of their strength most abundant organic compound on earth o Cellulose is composed of chains of sugars that are assembled into rods that are highly resistant to degradation resistant to being broken down strength similar to that of steel Starch composed of chains of glucose units but they are joined together in a different way resulting in it to be easily degraded and digested Wood is simply plant cell walls and is about 60 cellulose Corn seeds contain lots of starch that can be fermented to make ethanol grain alcohol Price of corn has tripled because corn is being used for a lot of things Hypothesis proposed explanation for some narrow observation about the natural world Not an educated guess Must lead to predictions that can be tested Theory broad explanation of some natural phenomenon that has been repeatedly tested and shown to hold true Ch 3 Above ground structures o Shoot consists of stem branches and leaves o Stem leaves are attached to this o Leaf petiole each leaf is attached to the stem by this stalk o Shoot tip a patch of tissue where new cells are formed by cell division and where most growth takes place o Lateral bud root base of each leaf where the petiole connects with the stem They are dormant shoot tips and when they are activated to grow a branch will form o Root tips end of lateral root where cell division and root growth take Below ground structures place Growth in length is due to cell division in the shoot and root tips Plants that live more than one year perennial plants grow in width by means of cell divisions in the body of the stem and root o Most obvious is trees because you can see tree rings The shoot tip makes the cells of the shoot but also the leaves lateral buds and flowers A flower is a modified shoot tip Basic flower parts o Petals o Pistil with stigma female part o Ovary part of pistil located at base becomes fruit o Ovules located inside ovary and contain eggs becomes seed o Stamens with anther o Filament stalk o Pollen contain male reproductive cells sperm carried from anther to stigma of the pistil in plant reproduction The female reproductive part egg is produced in the ovule and the male reproductive part sperm are produced in pollen Pollination the transfer of pollen to the stigma unique to plants Fertilization fusion of the
View Full Document
Unlocking...