Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Unit 4: Classification of Living Things Characteristics of Living Things • All living things: 1. Have Cellular Organization 2. Share Chemicals of Life 3. Need Energy 4. Respond to Surroundings 5. Grow and Develop 6. Reproduce Cellular Organization • Cell- The basic unit of structure and function in an organism • Unicellular- single celled • Multicellular- many cells Chemicals of Life • Carbohydrates- also called sugars, used for energy • Proteins- building material of cells • Lipids- building material of cells • Nucleic Acids- genetic material, gives cell instructions and controls cell’s activities Energy Use • Cells need energy to function and repair themselves! • The sun is the ultimate source of energy for all life on earth. Response to Surroundings • Stimulus- a change that causes an organism to react (ex: temp, light, sound) • Response- an action or change in behavior…happens because of stimulus Growth, Development, Reproduction • Growth- getting larger • Development- becoming more complex • Reproduction- passing on genetic material Life Comes From Life • Spontaneous Generation- living things can arise from nonliving things- HAS BEEN DISPROVEN • It took hundreds of years and lots of experiments to prove this Life Comes From Life • Francesco Redi designed one of the first controlled experiments. In his experiment, Redi showed that flies do not spontaneously arise from decaying meat. Life Comes From Life • Louis Pasteur’s carefully controlled experiment demonstrated that bacteria arise only from existing bacteria. The Needs of Living Things 1. Water- can only live a few days without water. Need it to obtain chemicals, digest, grow, move, and reproduce 2. Food- Used for energy source a. Autotrophs- Make their own energy using sunlight (plants) b. Heterotrophs- Obtain food by eating other organisms The Needs of Living Things 3. Living Space- organisms compete for space and resources 4. Stable Internal Conditions a. Homeostasis- maintaining stable internal conditions so cells can properly function (our body temp) Classification • Scientists classify so we can make sense of the world and living things, makes living things easier to study. • Classification- the process of grouping things based on their similarities • Taxonomy- the scientific study of how living things are classified Classification • Binomial Nomenclature- Created by Linneaeus, 2-part naming system. Uses Genus and Species. Ex: Homo sapiens • Genus- contains similar, closely-related organisms. Pumas and house cats are in Genus Felis. They have sharp, retractable claws, and hunt. • Species- group of similar organisms that can mate with each other and produce viable offspring Classification Levels of Classification- The more levels that 2 organisms share, the more characteristics they have in common Kingdom Phylum Class Order Family Genus Species Levels of Classification • As you move down the levels of classification, the number of organisms decreases. The organisms at lower levels share more characteristics with each other. Terms • Prokaryotes- Don’t have a nucleus • Eukaryotes- have a nucleus • Autotrophs- Make food from sun • Heterotrophs- obtain food from eating autotrophs and other heterotrophs Cell Wall- rigid layer of material that surrounds some cells to provide protection & support (plants, fungi, bacteria) plant bacteria animal No cell wall Three Domains of Life In the three-domain system of classifications, all known organisms belong to one of three domains–Bacteria, Archaea, or Eukarya. Bacteria (Prokaryotes, Autotrophs & Heterotrophs, Cell Walls) Kingdom: Eubacteria On your body, in foods we eat. Most aren’t harmful. Three Domains of Life Archaea (Prokaryotes, Autotrophs & Heterotrophs, Cell Walls) Eukarya (Eukaryotes) Kingdom: Archaebacteria Kingdoms: Protists- Can’t be classified as anything else. Very Diverse. salty, etc). Archaea means “ancient” in Greek. Auto/heterotrophs, uni/multicellular. Seaweed, Paramecium Live in extreme environments (dark, hot, (NO Cell Walls) Fungi- Mushrooms, molds, mildew. Most are multicellular. Heterotrophs. (Cell Walls) Absorb nutrients from decaying organisms. Plants- trees, moss, peas. Multicellular. (Cell Walls) Most live on land. Autotrophs. Very diverse. Animals- Multicellular. Heterotrophs. (NO Cell Walls) Very diverse. Taxonomic (Dichotomous) Key • Keys are used to determine the identification of organisms. • Statements are in pairs