Online courses directory (423)

Neurobiology is all about the biology of our nervous system, from the spinal cord to the brainand everything in between. The nervous system allows us to have conscious thoughts, enables us to learn, and gives us voluntary control of our muscles. Our understanding of neuroscience begins with the ancient Egyptians, who practiced surgical drilling to treat certain neurological disorders. The earliest philosophers believed that the heart (not the brain) was the center of consciousness and intelligence. As scientific knowledge matured and developed, philosophers disproved that belief but discovered that there is much more to neurobiology than “the brain.” Researchers found that there are literally hundreds of billions of nerves and other cells that cooperate and share information to make the nervous system work. Accordingly, neurobiology is an extremely complex field of study. This course is designed to provide you with an overview of the most important areas of neurobiological study. We will not pay much…

Human physiology is the study of the body’s processes, also known as functions. You already have experience with this subject, because you are a human and perform numerous functions each day to maintain your body’s balance or homeostasis. For example, gas exchange in your lungs provides the body’s cells with adequate oxygen supply needed to survive and carry out metabolic processes. Digestion of food components in your mouth, stomach, and small intestines breaks larger substances into molecules that can be absorbed in the small intestines and used for energy. White blood cells attack foreign bodies, such as bacteria and cells containing viruses to keep you free from infection. As you might expect, an understanding of physiology is paramount if you wish to pursue studies in health care, development, or even behavior. A doctor needs to understand how to relate a urine sample to kidney function. A nurse needs to know the importance of electrocardiogram results and heart activity. A medical laboratory sci…

This lab course supplements BIO304: Human Physiology [1].  Although we cannot virtually replicate the lab experience, this “lab” will familiarize you with scientific thinking and techniques and will enable you to explore of some key principles of human physiology. The material in this lab supplement relates to the material covered in the lecture and reading portion of the course.  While the lecture and reading portion focuses on big-picture concepts, here we will focus more on visual understanding, manipulation, and practical use of your knowledge.  You will review the physiology of the organ systems by using images of models, experiments, and videos.  Then you will be asked to assess your knowledge, which eventually can be put to practical or experimental use. Co-requisite: BIO304: Human Physiology [2]. [1] http://www.saylor.org/courses/bio304/ [2] http://www.saylor.org/courses/bio304/…

Genetics is the branch of biology that studies how traits are passed on from one generation to the next and why there are similarities and differences between related individuals. Prior to the discovery of genes, scientists knew that parents passed something down to their offspring, but they did not know how or what. Gregor Mendel’s famous experiments with peas indicated that certain features, such as pea texture and flower color, are encoded by two sets of traits and that the parental traits can be separated. Decades later, scientists discovered that parents passed down DNA, which was present in chromosomes. Since the discovery of DNA, we have come to appreciate the importance of chromosomes. Genomics is a relatively new field with the bold aim of understanding the function of every single gene in a genome, including the human genome. This field took off with the completion of the first sequenced genome, and after the completion of the Human Genome Project, it has attracted increasing research. Mendelian…

Botany is the study of plants.  Because species in the plant kingdom have characteristics that make them distinct from any other form of life, they are particularly interesting subjects for the study of evolution and physiology.  For example, whereas most organisms are dependent on other organisms for energy, plants can capture energy directly from photons of light and convert it into a usable form through the process of photosynthesis.  For this reason, plants are referred to as the “producers” in a habitat.  Unlike the cells of other organisms, plant cells have rigid cell walls constructed from the inside out (rather than the outside in) during mitosis and cytokinesis.  Plants also have a variety of unique reproductive and dispersal mechanisms that allow them to quickly adapt to, occupy, and invade far-flung areas, despite their general immobility. In this course, you will learn the basics of plant biology.  We will begin with plant anatomy, learning the names and functions of all of the parts o…

Even in ancient times, scholars believed that diseases could be spread by organisms too small to be seen by the naked eye. Before we discovered that bacteria cells were the real culprits, many attributed disease to other sources. Now that scientists have definitively identified the microscopic causes of various infectious diseases, microbiology, or the study of microscopic-sized organisms, has become an increasingly important field in biology and in the larger biomedical community. Most microbes are harmless. Some of them are essential for life on Earth, e.g. through their ability to fix nitrogen. Biotechnology, which is truly the industry of our times, takes advantage of microbes for the production of a variety of complex substances, and it also mass-produces natural and engineered microbes for human use. This course will cover a range of diverse areas of microbiology, including virology, bacteriology, and applied microbiology. This course will focus on the medical aspects of microbiology, as medical res…

Marine Biology is the study of ocean life.  As you might expect, life in salt water is vastly different from life in a terrestrial or freshwater environment due to factors like salinity, water circulation, and atmospheric pressure.  How, for example, can organisms living in salt water avoid dehydration?  How do organisms living in the depths of the ocean handle the immense pressure?  How do the environmental factors in marine communities affect biodiversity?  How do some animals manage to alternate between the demands of terrestrial life and the demands of marine life?  In this course, you will learn the answers to these questions and more.  This course will touch on a number of different subfields of biological study (including biochemistry, physiology, zoology, botany, and ecology) within the context of the ocean environment. You will start by learning about the ocean itself and its physical properties, as these properties influence the abundance, distribution, diversity, physiology, and behavior o…

Zoology is the scientific study of diversity of animal life, classification, physiology, behavior, and evolution. Unicellular organisms have evolved into complex multicellular forms. Organisms, both unicellular and multicellular, in various complex shapes and sizes are found in almost every habitat and environment. The field of zoology includes many subfields of biology as well as a vast diversity of unicellular and multicellular organisms. Animals first appeared in the fossil record an estimated 600 million years ago as multicellular protozoa. Over the next 70 million years, they radiated into an incredible number of different invertebrate phyla (which represent the majority of animal groups and species), and in the next 150 million years, vertebrate and invertebrate species began to colonize the land. Though the history of animals is extensive and the fossil record at times is conflicted and vague, understanding the historical connections between animals is important in order to understand modern-day rela…

Developmental biology asks questions about how organisms come into being, how life forms, and how complex structures develop and are differentiated.  These fundamental questions have been the subject of research for centuries; accordingly, this course you will teach you not only about the beginnings of organisms, but about the beginnings of developmental biology as a science.  Currently, developmental biologists use a range of tools and research focifrom molecular techniques to surgical manipulations to chemical and environmental studiesto answer these questions.  Their approaches are multi-faceted because developmental biology itself addresses topics of importance to a wide range of fields, from molecular biology to neuroscience to evolutionary biology. In this course, you will learn about the field of developmental biology from its origins to the present day.  We will take a look at historical experiments as well as modern techniques and the mechanisms of development.  You will follow a variety of me…

Molecular biology studies the molecular mechanisms of life, particularly those responsible for genes and their expression.  In the center of molecular biology are the nucleic acids, DNA and RNA, and how they contribute to the synthesis of proteins. After a historical introduction (Unit 1), this course describes the basic types of DNA and RNA structure and the molecular interactions that shape them (Unit 2).  Unit 3 describes how DNA is packaged within the cellular nucleus as chromosomes; in eukaryotes the DNA coils around histones to form nucleosomes that comprise the chromatin of the chromosomes.  The next three units describe the core processes of molecular biology: replication of DNA (Unit 4), transcription of DNA into messenger RNA (Unit 5), and translation of messenger RNA into a protein (Unit 6).  These are followed by modifications of these basic processes: regulation of gene expression (Unit 7), DNA mutation and repair (Unit 8), and DNA recombination and transposition (Unit 9). The course conclu…

One of the best ways to understand the present is to understand the past. Evolutionary Biology is the study of the changes in life forms over time - changes that have occurred over millions of years as well as those that have occurred over just a few decades. In this course, we will look at the various mechanisms of evolution, how these mechanisms work, and how change is measured. The concepts you learn in this course will serve as a foundation for studying fossil records and current classification schemes in biology. We will begin the course by reviewing the evolutionary concepts of selection and speciation. We will then learn to measure evolutionary change through comparisons with the Hardy-Weinberg Equilibrium, to understand the process of change through Game Theory, and to interpret and classify changes by creating phylogenies. The course will wrap up with a look at the history of life according to the fossil record and a discussion of the broad range of life forms as they are currently classified. At the…

Ecology is the study of interactions between organisms and between organisms and their environments.  Population ecology is the subfield of ecology that identifies those ecological factorsin the community or in the ecosystemthat regulate a population’s size. Ecosystems and communities involve complex interactions that have evolved over long periods of time.  The species that are present and the interactions we see between them are the result of evolution under the unique environmental pressures that exist in a given environment.  These interactions may be delicately intertwined, such that the loss of a single species from a community could mean the collapse of the entire community in a domino effect.  Thus, biologists are concerned with the preservation of biodiversity in ecosystemsretaining as many different species in the ecosystem as possible so the intricate relationships among species are preserved. In recent years, we have seen a decrease in the biodiversity of ecosystems.  Human activities a…

Biochemistry is the study of the chemical processes and compounds, such as cellular makeup, that bring about life in organisms.  It is a combination of multiple science fields; you can think of it as general and cell biology coupled with organic and general chemistry.  Although living organisms are very complex, from a molecular view, the material that constitutes “life” can be broken down into remarkably simple molecules, much like the breakdown of our English language to the English alphabet.  Although there exists thousands upon thousands of molecules, they all breakdown into four core components: nucleic acids, amino acids, lipids, and carbohydrates.  As we can make hundreds of thousands of words from just 26 letters, we can make thousands of different biomolecules from those 4 components.  For example, the human genome, containing the necessary information to create a human being, is really just one very long strand of 4 different nucleotides. This course is structured around that approach, so…

The purpose of this course is to explore the subject of human disease, placing special emphasis on the cause of disease at the tissue level.  We will pay close attention to the underlying mechanisms that initiate and perpetuate the disease state.  Much can be learned about the causes of disease at the molecular and cellular level; we will accordingly spend quite a bit of time examining molecules, cells, and tissues and determining how the disruption of their normal functioning by various known and unknown causes can lead to disease. We will begin this course with a basic review of molecules, cells, and tissues in the human body.  We will then discuss the body’s first line of defense, the inflammatory reaction, and the immune system. Finally, we will survey the body’s organ systems.  We will approach each of the systems by examining the ways in which a prototype disease impacts its functioning.  (These “prototypes” will be diseases that impact a large number of patients around the world.)  We…

Biotechnology is the application of biology and biological concepts to science and engineering.  It is the crossroad of the biological sciences with other major disciplines of science, from organic chemistry to mechanical engineering.  The earliest applications of biotechnology involve people of ancient civilizations using organisms to create bread and wine.  The discovery of the Penicillium mold to combat infection is another famous example, as its production involved a specially designed fermentation process using microorganisms.  Nowadays, scientists use almost all aspects of biology in their applications, from DNA to protein to cellular organelles.  Living organisms, especially microorganisms, are thought of as biochemical machinery, able to be edited and changed to create new purposes.  We could program them to create insulin for diabetes patients or to produce fuel for our cars.  Biotechnology is nearly limitless in its applications. As biotechnology is a very diverse topic, this course will in…

Cancer has existed among humans since humans themselves began and has been a subject of urgent interest from very early in our history.  What we call “cancer” consists of a number of different diseases with one fundamental similarity: they are all initiated by the unchecked proliferation and growth of cells in which the pathways and systems that normally control cell division and mortality are absent.  Cancer-cell abnormalities are often due to mutations of the genes that control the cell cycle and cell growth.  To understand cancer cells, then, one must first understand the processes that regulate normal cell cycles. This course will cover the origins of cancer and the genetic and cellular basis for cancer.  It will examine the factors that have been implicated in triggering cancers; the intercellular interactions involved in cancer proliferation; current treatments for cancer and how these are designed; and future research and treatment directions for cancer therapy.

The advent of computers transformed science.  Large, complicated datasets that once took researchers years to manually analyze could suddenly be analyzed within a week using computer software.  Nowadays, scientists can use computers to produce several hypotheses as to how a particular phenomenon works, create computer models using the parameters of each hypothesis, input data, and see which hypothetical model produces an output that most closely mirrors reality. Computational biology refers to the use of computers to automate data analysis or model hypotheses in the field of biology.  With computational biology, researchers apply mathematics to biological phenomena, use computer programming and algorithms to artificially create or model the phenomena, and draw from statistics in order to interpret the findings.  In this course, you will learn the basic principles and procedures of computational biology.  You will also learn various ways in which you can apply computational biology to molecular and cell…

In this course, you will study microscopic anatomy. The study of the structure of a cell, tissue, organ, or related feature is known as anatomy. Gross anatomy (or macroscopic anatomy) involves examining anatomical structures that can be seen with the naked eye, whereas microscopic anatomy is the examination of minute anatomical structures that cannot be observed without the help of visual enhancement, such as a microscope. The terms microscopic anatomy and histology (the study of microscopic structure of animal and plant tissue) are used interchangeably. Many times it will be necessary to survey gross anatomy so that when you focus in on the microscopic anatomy you will have a geographical idea of the location within the body. This course makes use of microscope slides of anatomical structures to aid in the discussions of anatomy. Unit 1 begins with an overview of basic cell structure. The study of cells is known as cytology. Cells contain numerous structures that can only be seen with the aid of specialize…

Immunology is the study of our immune system, a highly sophisticated system that defends us against all disease-causing invaders by identifying and neutralizing such threats. Even though we might get sick every now and then, the immune system does an incredible job of warding off infection given how many infectious agents (thousands!) we come into contact with every day. This becomes most apparent when a healthy individual compares himself or herself to an individual with little or no immune response who cannot survive in a normal environment and must rely on specialized rooms much cleaner than even a surgery room. Before the discovery of immunity, we used to associate sickness and disease with various superstitions and beliefs. Only with the discovery of bacteria, viruses, and our own cells did scientists slowly piece together the modern theory of our immune system. Our overall system can be broken down into two sub-systems, each with its own unique cells, molecules, and functions. Our cells are in turn capa…

This is an introductory course in biochemistry, designed for both biology and chemical engineering majors. A consistent theme in this course is the development of a quantitative understanding of the interactions of biological molecules from a structural, thermodynamic, and molecular dynamic point of view. A molecular simulation environment provides the opportunity for you to explore the effect of molecular interactions on the biochemical properties of systems. This course assumes that students have taken introductory chemistry, including basic thermodynamics, as well as introductory organic chemistry. An introductory biology course is not a prerequisite for the course, but students would benefit from some prior exposure to biology, even at the high school level. Required mathematical skills include simple algebra and differential calculus.