Chapter 1 - Review PDF

CHAPTER 1 –REVIEW 1.1 The Characteristics of Life Biology is the area of science that studies life. Although living organisms are diverse, they have certain characteristics in common. Living organisms: are organized. These levels of organization extend from the cell (the basic unit of life...

CHAPTER 1 –REVIEW 1.1 The Characteristics of Life Biology is the area of science that studies life. Although living organisms are diverse, they have certain characteristics in common. Living organisms: are organized. These levels of organization extend from the cell (the basic unit of life) to multicellular tissues, organs and organ systems. Atoms and molecules are the nonliving components of cells. Above the level of the cell, organisms are organized into populations and communities. Ecosystems and the biosphere represent the highest levels of biological organization. require materials and energy. All living organisms need an outside source of materials and energy. Metabolism is the term used to summarize these chemical reactions in the cell. Photosynthesis is an example of a metabolic process. maintain homeostasis. Homeostasis is the ability to maintain a stable internal environment. respond to stimuli. These stimuli help an organism react to changes in its environment, such as the presence of food. reproduce and develop. Organisms reproduce to pass on their genetic information, included in the genes of their DNA, to the next generation. Mutations introduce variation into the DNA. Development is the series of steps that an organism proceeds through to become an adult. have adaptations. Adaptations allow an organism to exist in a particular environment. Evolution is the accumulation of these changes over multiple generations. 1.2 Evolution and the Classification of Life Life on Earth is diverse, but the theory of evolution unifies life and describes how all living organisms evolved from a common ancestor. Natural selection describes the process by which living organisms are descended from a common ancestor. Mutations occur within a population, creating new traits. The agents of natural selection, present in both biological and physical environments, shape species over time and may create new species from existing ones. In taxonomy, organisms are assigned an italicized binomial nomenclature that consists of the genus and the specific epithet. From the least inclusive to the most inclusive category, each species belongs to a genus, family, order, class, phylum, kingdom, and finally domain. Systematics is the study of evolutionary relationships between species. The three domains of life are Archaea, Bacteria, and Eukarya. Domain Archaea and domain Bacteria contain prokaryotic organisms that are structurally simple but metabolically complex. Domain Eukarya contains the eukaryotic protists, fungi, plants, and animals. Protists range from single-celled to multicellular organisms and include the protozoans and most algae. Among the fungi are the familiar molds and mushrooms. Plants are well known as the multicellular photosynthesizers of the world, while animals are multicellular and ingest their food. An evolutionary tree shows how the domains are related by way of common ancestors. 1.3 The Process of Science When studying the natural world, scientists use a process called the scientific method. Observations, along with previous data, are used to formulate a hypothesis. Inductive reasoning allows a scientist to combine facts into a hypothesis. New observations and/or experiments are carried out in order to test the hypothesis.Deductive reasoning allows for the development of a prediction of what may occur as a result of the experiment. A good experimental design includes an experimental variable and a control group. Scientists may use models and model organisms in their experimental design. The data from the experimental and observational results are analyzed, often using statistical methods. The results are often presented in tables or graphs for ease of interpretation. A conclusion is made as to whether the results support the hypothesis or do not support the hypothesis. The results may be submitted to a scientific publication for review by the scientific community. Over time multiple conclusions in a particular area may allow scientists to arrive at a theory (or principle or law), such as the cell theory or the theory of evolution. The theory of evolution is a unifying concept of biology. 1.4 Challenges Facing Science While science investigates the principles of the natural world, technology applies this knowledge to the needs of society. Some challenges that scientists are investigating include: The loss of biodiversity and habitats such as coral reefs and rain forests. This often results in the extinction of species. Emerging diseases, such as avian influenza and SARS The impact of climate change and global warming Test your knowledge: 1. Choose the correct order of classification from most inclusive to exclusive. Domain Kingdom Phylum Class Order Family Genus Species 2. Which listing correctly indicates a sequence of increasing biological organization? molecule cell organelle atom 3. Is it true that the classification system most commonly used by biologists today contains five domains?. 4. Do humans have an exaggerated impact on the ecosystem through their use of extra sources of energy and raw materials, and the production of extra wastes that must be handled? 5. What are living organisms are made up of?. 6. Do living things must obey the laws of chemistry and physics. 7. Do living organisms show biological organization and other common characteristics of life? 8. What are emergent properties, can it be used to distinguish living organisms from nonliving things? 9. How is hypothesis is tested? 10. What are the characteristics of living organisms? 11. Which domain contains the most primitive prokaryotes that live in extreme environments? 12. A study is conducted to determine the average length and weight of loblolly pine tree needles in the southeast United States. Is this data obtained through observation or experimentation? 13. Arrange in order, the levels of ecological study from most inclusive to most exclusive: ecosystem, biosphere, population, community, individual organism 14. What is the definition that best describes a population? 15. Is it true that both living and nonliving entities adapt to the environment.