Biology A- Night School Notes

Traditionally, there were two main branches of biology: botany (the study of plants) and zoology (the study of animals). Today, there are dozens. ● Science as process: The word science is derived from a Latin verb mean ...

Traditionally, there were two main branches of biology: botany (the study of plants) and zoology (the study of animals). Today, there are dozens. ● Science as process: The word science is derived from a Latin verb meaning "to know." That is, biology is an ongoing process of learning, not just a list of facts. ● Evolution: Evolution is simply how living things evolve, or change, over time. It explains inherited similarities in organisms and causes of variation. ● Energy transfer: All organisms perform work as they move, grow, and reproduce and need an energy source to do so. Organisms constantly transfer energy to their surroundings, and vice versa. This transfer involves the conversion of one form of energy into another. ● Continuity and change: Organisms reproduce to ensure their species continues. But combining genes also results in variations in offspring. ● Relationship of structure to function: Every type of organism has developed parts to adapt to its habitat. Birds have different kinds of beaks, and plants have different kinds of seeds, for example. ● Regulation: Also called homeostasis. Cells, animals, and ecosystems work to maintain stable internal conditions, such as body temperature, even when external conditions change. ● Interdependence in nature: The flow of energy and cycling of matter are the two processes that determine the relationships between organisms and their surroundings. ● Science, technology, and society: Scientific inquiry should consider the ethical and social impact of the research. In other words, scientists must make decisions based on what society should do over what it can do. 460 B.C Hippocrates was a Greek physician. He is called the "Father of Medicine." He was the first physician to reject superstitions believed to be the cause of illness. He believed that diseases weren't punishments inflicted by God but rather the results of living habits, diet, and environmental factors. Hippocrates and his followers were the first to describe many diseases and medical conditions. He began to categorize illnesses as acute, chronic, endemic, and epidemic. The Hippocratic Oath that doctors take is named after him. 384 B.C Aristotle was a Greek philosopher who wrote about many subjects, including physics, zoology, and biology. He wrote several books on animals with striking observations about sea life. He classified animals as "animals with blood" (today known as vertebrates) and "animals without blood" (today known as invertebrates). His system of classifying plants and animals is very similar to the Linnaean classification system used today. 1546 Girolamo Fracastoro was an Italian physician and poet. He studied epidemic diseases and concluded that they spread through tiny particles that could transmit infection by direct or indirect contact or even without contact over long distances. He wrote a poem about syphilis. The disease was named after the poem's title. 1683 Anton van Leeuwenhoek was a Dutch naturalist and microbiologist. He is commonly known as the "Father of Microbiology." He is best known for his improvements in the microscope. In 1683, he described and illustrated five different kinds of bacteria present in the mouth. 1796 Edward Jenner was an English country doctor who pioneered vaccination. Jenner's discovery in 1796 that inoculation with cowpox gave immunity to smallpox was a medical breakthrough. 1858 Charles Darwin and Alfred Wallace published a paper in 1858 on the tendency of species to form varieties and on the perpetuation of varieties and species by natural means of selection. These concepts laid the groundwork for the theory of evolution, which profoundly impacts modern biology. 1865 Claude Bernard was a French physiologist. In 1865, he wrote the dissertation An Introduction to the Study of Experimental Medicine, where he described what makes a scientific theory good and what makes a scientist a true discoverer. 1865 Gregor Mendel is the founder of the study of genetics. In 1865, he published the paper Experiments in Plant Hybridization, which laid the foundation for our basic understanding of the principles of genetic inheritance. 1878 Joseph Lister was an English surgeon. In 1867, he published the paper Antiseptic Principle of the Practice of Surgery. He promoted the idea of sterile surgery by using carbolic acid to sterilize surgical instruments and to clean wounds. This led to a decrease in post-operative infections. 1881 Louis Pasteur was a French chemist and microbiologist. In 1881, he publicly demonstrated the use of his anthrax vaccine. This experiment was similar to the method of vaccinating animals against cowpox carried out by Edward Jenner. This repeated investigation provided more evidence for the germ theory. He and Claude Bernard used this theory to devise a process to control the growth of micro-organisms in food. This process is pasteurization. 1928 Sir Alexander Fleming was a Scottish biologist and pharmacologist. In May 1928, he revolutionized medicine by discovering the world's first antibiotic, penicillin. 1944 In 1944, Oswald Avery, Colin MacLeod, and Maclyn McCarty demonstrated that DNA is the substance that causes bacterial transformation. Their experiment was based on a previous experiment by Frederick Griffith in which he had demonstrated the phenomenon of transformation. He called the agent responsible for transformation "the transforming principle." 1953 In 1953, James Watson and Francis Crick proposed the double helix or spiral staircase structure of the DNA molecule. They confirmed that DNA carries hereditary information. This discovery was probably the most significant biological discovery of the twentieth century. 1967 Christiaan Barnard was a South African cardiac surgeon. Barnard experimented for several years with animal heart transplants. On December 3, 1967, he performed the world's first successful human-to-human heart transplant operation. This operation lasted for nine hours. Dr. Barnard took the first steps into a new form of organ transplant surgery, which is now common medical practice. 1990 William French Anderson is a U.S. physician, geneticist, and molecular biologist. He is considered a pioneer of gene therapy. He and his team performed the first successful gene therapy on a four-year-old girl suffering from an immune disorder. 1996 Dolly, the first mammal to be successfully cloned from an adult somatic cell, was born July 5, 1996. The cloning was carried out using nuclear transfer where the cell nucleus from an adult cell is transferred into a developing egg cell that has had its nucleus removed. Dolly's birth has prompted many debates on the ethics of cloning. 2001 The Human Genome Project was an international scientific research project aimed at identifying and mapping the genes in human DNA. In 2001, the first draft of the human genome was released. It was the result of international cooperation in the fields of genomics and computing technology. Mapping of human genes is important in the development of new medicines and other healthcare advancements. The project ended in 2003, but additional analysis continues. "What is the structure of the proteins that coat a virus?" The microbiologist wants to test these hypotheses: 1. If the virus behaves a lot like HIV, the virus coat will have two receptor proteins. 2. If the virus is grown on nutrient agar, the coat proteins will be modified. Here, the first hypothesis is testable because the receptor proteins can be viewed through the microscope. However, the second hypothesis cannot be tested because the conditions to test it can never be created. A virus cannot grow on nutrient agar, which is a cell-free medium. Data analysis consists of four major steps: 1. Classify the data into appropriate categories. 2. Draw an inference from the data. 3. Calculate the appropriate values. 4. Draw a conclusion about the data. Common Metric Units Length 1 meter = 100 centimeters 1000 meters = 1 kilometer Mass 1 kilogram = 1000 grams Volume 1 liter = 1000 milliliters Temperature 0°C = freezing point of water 100°C = boiling point of water Metric System Standardized measurement is essential in scientific research. Today, most scientists use the metric system of measurement. The units of this system are assigned specific standards and are scaled in multiples of 10. The original metric system was revised in recent years and is now called the International System of Units, or SI for short. This system measures length in kilometers, mass in kilograms, volume in liters, and temperature in degrees Celsius. Biology, the study of life, is the science on which many kinds of study are based: medicine, nutrition, molecules, ecosystems, and more. Several themes, such as evolution and energy transfer, are consistent throughout Biology's many disciplines. Research methodologies have undergone a significant change over the years. Observation, investigation, and experimentation remain the backbone of research, but microscopes and computers have greatly enhanced scientific knowledge and study. The data gathered by researchers must be organized and analyzed so that it is useful. Tables and graphs are good ways to represent data. Biological research has contributed directly to life as we know it: how we grow crops, how we identify and treat diseases, and even what foods we eat are all direct results of biological research. Biotechnology (for example, converting corn into fuel) and food technology (for example, developing tomatoes with skins tough enough to be transported) are examples of how we see biology applied every day. Researchers who pursue a specific area of interest may someday make great achievements. For example, an interest in diseases could lead to finding a cure for diabetes. Or an interest in plants could lead to discovering more efficient ways to grow our food without losing its good taste. As scientists learned more about nature and science, they began to challenge established ideas like spontaneous generation. This was the beginning of what is now known as scientific inquiry. Scientists use three key methods to research and analyze data: observation, investigation, and experimentation. Scientific inquiry begins with observation. It is a process in which scientists gather information in an orderly manner. They record their observations, which become data that they categorize. Data is of two types: Numerical data is called quantitative data. Descriptive data, data that cannot be counted, is called qualitative data. An example of quantitative data is, "A plant has 10 leaves." An example of qualitative data is, "The leaves are healthy." Based on the data she's gathered, a scientist may propose a hypothesis. A hypothesis is a question framed by a scientist to explain a set of observations. It's a prediction that must be testable. So the scientist must conduct experiments or do more investigation. A hypothesis isn't always proven correct. Experiments or investigation may prove the hypothesis wrong. Then the scientist must reformulate the hypothesis and start over again. An experiment must be repeated enough times to ensure that the outcome is always the same. Once testing is complete, the scientist analyzes the results and then concludes that her hypothesis is correct, partially correct, or just plain wrong. Once a hypothesis is accepted as correct and after repeated testing, it becomes a theory. A theory may be disproven if contrary evidence later becomes available. Theories are different from scientific laws, which are statements accepted at face value because they have always been observed to be true. Advancements in research tools are key to the growth of most sciences. Probably the first big advance in scientific tools was the invention of the microscope. The invention of computers also has made an enormous contribution to all the sciences. Microscopes