Chapter 1 intro to life on earth
- 1. Chapter 1 An Introduction to Life on Earth
- 2. What is Biology? --- The science of living organisms and life processes.
- 3. So what exactly is life?
- 4. Life: An evanescent phenomenon dependent for its continued existence, and perpetuation, on cyclic enzymatic reactions in an environment consisting principally of protein and water. Student Dictionary of Biology. (1972) Van Nostrand Reinhold Company, New York. Life: the property by which living organisms are distinguished from dead Organisms or inanimate matter. Websters II New Riverside Dictionary. These definitions suck terribly. Neither of the Biology texts (for majors or non-majors) that we use include the term “life” in their glossaries.
- 5. The characteristics of life: 1. Complex, organized structure 2. Response to stimuli - a change outside (or inside) leads to another change 3. Homeostasis - the ability to maintain the structure and regulate the internal environment. 4. Ability to acquire material and energy -The material and energy are often transformed 5. Growth 6. Reproduction - either sexual or asexual DNA is genetic information, the “blueprint” for the offspring 7. Ability to evolve - to change to fit the environment
- 6. Complex, organized structure The complexity of life is built in levels. Fig. 1-8
- 7. Each level has ingredients or components which interact to make something greater than the sum of the parts. Emergent Properties Example: NaCl (Sodium Chloride) Sodium = solid metal Chlorine = poisonous gas Put them together = table salt
- 8. That part of Earth inhabited Biosphere by living organisms; includes both the living and nonliving components Earth's surface A community together with its Ecosystem nonliving surroundings snake, antelope, hawk, bushes, grass, rocks, stream Two or more populations of different Community species living and interacting in the same area snake, antelope, hawk, bushes, grass Very similar, potentially interbreeding Species organisms Members of one species inhabiting Population the same area herd of pronghorn antelope Fig. 1-1
- 9. Multicellular An individual living thing composed Organism of many cells pronghorn antelope Organ Two or more organs working together in the execution of System a specific bodily function the nervous system A structure usually Organ composed of several tissue types that form a functional unit the brain A group of similar cells that perform Tissue a specific function nervous tissue Cell The smallest unit of life nerve cell Fig. 1-1
- 10. A structure within a cell that Organelle performs a specific function mitochondrion chloroplast nucleus Molecule A combination of atoms water glucose DNA The smallest particle of an element Atom that retains the properties of that element hydrogen carbon nitrogen oxygen Subatomic Particles that make up an atom Particle proton neutron electron Fig. 1-1
- 11. If you put a plant in your window, the stem will lean in the direction of the sun. This is an example of which characteristic of life? • Living things are organized. • Living things respond to stimuli. • Living things maintain homeostasis. • Living things need energy.
- 12. Response to stimuli Organisms react to external and internal stimuli. Some reactions are slow and can’t be seen.
- 13. Our body works to keep our temperature at about 98.6ºF. This is an example of which characteristic of living things? • Living things are organized. • Living things respond to stimuli. • Living things maintain homeostasis. • Living things need energy.
- 14. Homeostasis -the ability to maintain the structure and regulate the internal environment. In order to stay alive and function, organisms must keep the conditions within their bodies fairly constant.
- 15. Ability to acquire material and energy The material and energy are often transformed . Energy is used to maintain a high level of complexity and organization, to grow, and to reproduce.
- 16. Organisms can take in nutrients (food) for raw materials and energy (heterotrophs) Or they can use sunlight for energy (photosynthesis) to produce energy- rich sugar molecules (autotrophs)
- 17. The word heterotroph means “other-feeder” or: • Able to photosynthesize. • Able to make its own food. • Must rely on other organisms for energy. • Make its own energy.
- 18. Metabolism changes the raw material and energy into the forms which are needed for maintenance, growth, reproduction, etc . Metabolism is basically the sum total of all of the chemical reactions that occur within an organism.
- 19. Growth All organisms grow during their life
- 20. Reproduction Individuals reproduce their own kind.
- 21. The genetic information for “How to build an offspring” is stored in the DNA of the parent(s) and that information is passed on to the offspring. Fig. 1.6
- 22. Evolution If the environment changes, then the population of organisms must change to fit the environment or face the possibility of extinction. This process of survival of the fittest is natural selection
- 23. The evolutionary changes are usually slow, taking several generations and occur by the accumulation of DNA changes known as mutations.
- 24. All life forms have these characteristics in common, yet there is an amazing diversity in the forms of life on the planet.
- 25. All living organisms are organized into groups. Each of the major organizational groups are called domains
- 26. There are two prokaryotic domains; Bacteria and Archaea and a eukaryotic domain; Eukarya. Fig. 1.11
- 27. In the figure, which organism is most closely related to humans? • Bacterium • Protist • Archaean • Tree Figure 1-11
- 28. Within the domains are at least 6 groups known as kingdoms Each kingdom has different attributes which define them. (See table 1-1)
- 29. The first difference is cell type PROKARYOTES EUKARYOTES No nucleus or nuclear Nucleus with a nuclear envelope envelope Genetic material in a Genetic material within “nucleoid region” the nucleus No organelles or Contains cytosol with internal membranes membrane-bound organelles
- 30. Kingdom Cell Type Bacteria Prokaryotic Archaea Prokaryotic Protista Eukaryotic Fungi Eukaryotic PlantaeEukaryotic Animalia Eukaryotic
- 31. The next property is how many cells the organism has Single cell (unicellular) or many cells (multicellular)
- 32. Kingdom Cell Type Cell Number Bacteria Prokaryotic Unicellular Archaea Prokaryotic Unicellular Protista Eukaryotic Unicellular Fungi Eukaryotic Multicellular Plantae Eukaryotic Multicellular Animalia Eukaryotic Multicellular
- 33. The third attribute in the classification of organisms at the kingdom levels is how the organism obtains nutrients/energy Three basic methods Make food using sunlight - photosynthesis Uptake of nutrients by absorption Uptake by eating or ingestion
- 34. Kingdom Cell Type Cell Number Nutritional Method Bacteria Prokaryotic Unicellular Absorp./photosyn. Archaea Prokaryotic Unicellular Absorp./photosyn. Protista Eukaryotic Unicellular Absorp./photosyn./ingestion Fungi Eukaryotic Multicellular Absorption Plantae Eukaryotic Multicellular Photosynthesis Animalia Eukaryotic Multicellular Ingestion
Editor's Notes
- #7: Figure :1-1 part c Title: Life is both complex and organized part c Organized and complex Caption: Living things have both complexity and organization. The waterflea, Daphnia pulex , is only 1 millimeter long (1/1000 meter; smaller than the letter “i”), yet it has legs, a mouth, a digestive tract, reproductive organs, light-sensing eyes, and even a rather impressive brain in relation to its size.
- #9: Figure :1-2 top Title: Levels of organization of matter top Caption: All life has a chemical basis, but the quality of life itself emerges on the cellular level. Interactions among the components of each level and the levels below it allow the development of the next-higher level of organization. Exercise Think of a scientific question that can be answered by investigating at the cell level, but that would be impossible to answer at the tissue level. Then think of a question answerable at the tissue level but not the cell level. Repeat the process for two other pairs of adjacent levels of organization.
- #10: Figure :1-2 middle Title: Levels of organization of matter middle Caption: All life has a chemical basis, but the quality of life itself emerges on the cellular level. Interactions among the components of each level and the levels below it allow the development of the next-higher level of organization. Exercise Think of a scientific question that can be answered by investigating at the cell level, but that would be impossible to answer at the tissue level. Then think of a question answerable at the tissue level but not the cell level. Repeat the process for two other pairs of adjacent levels of organization.
- #11: Figure :1-2 bottom Title: Levels of organization of matter bottom Caption: All life has a chemical basis, but the quality of life itself emerges on the cellular level. Interactions among the components of each level and the levels below it allow the development of the next-higher level of organization. Exercise Think of a scientific question that can be answered by investigating at the cell level, but that would be impossible to answer at the tissue level. Then think of a question answerable at the tissue level but not the cell level. Repeat the process for two other pairs of adjacent levels of organization.
- #12: Question: 1-11 Answer: 2 Diff: Moderate Text Ref: Section 1.3 Skill: Conceptual Also relates to: Chapter 7 Notes: Students tend to think of a response to a stimulus as a quick movement, such as dodging a ball thrown at their head. It is good to point out that while plants do not seem very active, they do indeed respond to stimuli.
- #14: Question: 1-10 Answer: 3 Diff: Moderate Text Ref: Section 1.3 Skill: Conceptual Also relates to: Chapter 6 Notes: This question provides students with an example of a biological property that is actively regulated during the life of the organisms; that is, the maintenance of a constant body temperature. This process is an example of homeostatic control.
- #18: Question: 1-13 Answer: 3 Diff: Moderate Text Ref: Section 1.3 Skill: Conceptual Notes: Mode of energy acquisition will come up in many chapters in the book. It is important for students to understand the difference between an autotroph and a heterotroph.
- #20: Figure :1-6 Title: Living things reproduce Caption: As they grow, these polar bear cubs will resemble, but not be identical to, their parents. The similarity and variability of offspring are crucial to the process of evolution.
- #21: Figure :1-6 Title: Living things reproduce Caption: As they grow, these polar bear cubs will resemble, but not be identical to, their parents. The similarity and variability of offspring are crucial to the process of evolution.
- #28: Question: 1-14 Answer: 4 Diff: Moderate Text Ref: Section 1.4 Skill: Conceptual Notes: The first three choices are unicellular organisms and are generally primitive compared to a tree, which is a multicellular organism with a complex physiology, similar to these properties seen in humans.