Conexion Samanta
Date de parution : 26 novembre 2010
| Saison 1 - épisode 1 | The Scope of Life The first lecture gives an overview of biology, raising key questions about the nature of life and the origin of living things, and concludes with... | |
| Saison 1 - épisode 2 | More on the Origin of Life This lecture outlines the challenges of evolution for living entities such as we recognize today, and reviews experimental data suggesting how these... | |
| Saison 1 - épisode 3 | The Organism and the Cell Professor Nowicki outlines the hierarchical nature of biological systems and introduces two fundamental levels of the hierarchy: the organism and... | |
| Saison 1 - épisode 4 | Proteins—How Things Get Done in the Cell This lecture describes the four major classes of biomolecules; lipids, carbohydrates, nucleic acids, and proteins and discusses the role of proteins... | |
| Saison 1 - épisode 5 | Which Molecule Holds the Code? Key experiments in the first half of the 20th century led to the conclusion that DNA is the information-carrying molecule. | |
| Saison 1 - épisode 6 | The Double Helix Experiments by Rosalind Franklin, Maurice Wilkins, and others led to the discovery by James Watson and Francis Crick of the double helix structure... | |
| Saison 1 - épisode 7 | The Nuts and Bolts of Replicating DNA After describing how the theory of DNA replication was confirmed, Professor Nowicki summarizes the process, which has been the key to understanding... | |
| Saison 1 - épisode 8 | The Central Dogma We are introduced to the central dogma of molecular biology: Genetic information flows in one direction only from DNA to RNA to proteins, not in... | |
| Saison 1 - épisode 9 | The Genetic Code How is protein structure coded in DNA? This lecture describes the experiments that cracked the code and examines the code's defining properties. | |
| Saison 1 - épisode 10 | From DNA to RNA Step one in the journey of genetic information from DNA to proteins is the process of transcription, by which messenger RNA is made from a DNA... | |
| Saison 1 - épisode 11 | From RNA to Protein Completing the description of how genetic information finds its way to functional proteins, this lecture covers the process of translation, which is... | |
| Saison 1 - épisode 12 | When Mistakes Happen We learn the causes for errors that creep into DNA during copying and the mechanisms that have evolved to detect and repair those errors. | |
| Saison 1 - épisode 13 | Dividing DNA Between Dividing Cells Moving from the molecular level to the level of cells and organisms, this lecture addresses the question: When a new being is produced, how does it... | |
| Saison 1 - épisode 14 | Mendel and His Pea Plants The first of two lectures on Gregor Mendel's 19th-century experiments on the genetics of pea plants shows how this work anticipated the modern... | |
| Saison 1 - épisode 15 | How Sex Leads to Variation This lecture continues the discussion of Mendel's contributions to genetics, turning to subsequent experiments in which he looked at the... | |
| Saison 1 - épisode 16 | Genes and Chromosomes We explore the understanding of the cellular and molecular basis of genetics that emerged after Mendel at the turn of the 20th century. | |
| Saison 1 - épisode 17 | Charles Darwin and the Origin of Species At almost the same time that Mendel was working on his laws of inheritance, Charles Darwin was completing his theory of natural selection, which... | |
| Saison 1 - épisode 18 | Natural Selection in Action This lecture presents several examples that demonstrate natural selection in action, including data from both field studies and laboratory... | |
| Saison 1 - épisode 19 | Reconciling Darwin and Mendel The apparent conflict between Mendel and Darwin was resolved through the modern synthesis, which models gene frequency changes in populations. | |
| Saison 1 - épisode 20 | Mechanisms of Evolutionary Change Natural selection is not the only cause of evolution. Other factors can produce changes in the gene pool of a population, the most notable being... | |
| Saison 1 - épisode 21 | What Are Species and How Do New Ones Arise? Professor Nowicki discusses problems with the biological species concept, introduces alternate definitions, and describes the process of allopatric... | |
| Saison 1 - épisode 22 | More on the Origin of New Species Continuing the discussion of how new species arise, this lecture looks at sympatric speciation, which occurs in the absence of physical separation... | |
| Saison 1 - épisode 23 | Reconstructing Evolution How do biologists organize the enormous diversity of living things? We learn about phylogenetic systematics as an approach for reconstructing... | |
| Saison 1 - épisode 24 | The History of Life, Revisited This lecture takes a final look at the concept of information and evolution in biology by returning to the question of how an original, primordial... | |
| Saison 1 - épisode 25 | From Cells to Organisms This lecture recaps material presented to this point and introduces the second major section of the course,;Development and Homeostasis, by looking... | |
| Saison 1 - épisode 26 | Control of Gene Expression I What makes cells different? We look at the mid 20th-century experiments of Jacques Monod and François Jacob in search of the mechanisms of gene... | |
| Saison 1 - épisode 27 | Control of Gene Expression II We continue our investigation of how the proteins in a cell are determined by mechanisms that turn on and off the expression of specific genes. | |
| Saison 1 - épisode 28 | Getting Proteins to the Right Place Producing the right proteins at the right time is only the first step. This lecture explains how proteins find themselves in the right places inside... | |
| Saison 1 - épisode 29 | Genetic Engineering and Biotechnology The mechanisms cells use to replicate and transcribe DNA have shown researchers how to modify genes, transfer genetic material, and sequence genes. | |
| Saison 1 - épisode 30 | How Cells Talk—Signals and Receptors This lecture is the first of two that explore how molecular messages control cell function, focusing on how signals outside the cell get their... | |
| Saison 1 - épisode 31 | How Cells Talk—Ways That Cells Respond Continuing the discussion of extracellular signals and cell function, this lecture focuses on the molecular mechanisms by which signals can change... | |
| Saison 1 - épisode 32 | From One Cell to Many in an Organism How does a single cell develop into a fully formed organism? This lecture outlines the major questions surrounding development. | |
| Saison 1 - épisode 33 | Patterns of Early Development Professor Nowicki describes the four earliest stages of animal development;fertilization, cleavage, gastrulation, and organogenesis;outlining the... | |
| Saison 1 - épisode 34 | Determination and Differentiation Developmental processes cause cells to differentiate into many different types of cells. One such mechanism is cytoplasmic segregation. | |
| Saison 1 - épisode 35 | Induction and Pattern Formation The second major mechanism involved in differentiation is induction, in which cells stimulate each other to develop in different ways. | |
| Saison 1 - épisode 36 | Genes and Development This lecture examines the development of the Drosophila melanogaster (fruit fly) as an example of the influence of specific genes on pattern... | |
| Saison 1 - épisode 37 | Homeostasis Homeostasis refers to an organism's ability to maintain a constant internal environment. We explore the nature of this mechanism and look at... | |
| Saison 1 - épisode 38 | Hormones in Animals Homeostasis requires the different parts of a complex organism to communicate with each other. This lecture focuses on the endocrine system, which... | |
| Saison 1 - épisode 39 | What is Special about Neurons? This lecture begins a discussion of the nervous system by examining neurons and the properties that enable them to transmit information over long... | |
| Saison 1 - épisode 40 | Action Potentials and Synapses We review the initiation of action potentials and discuss how the anatomy of the neuron allows action potentials to propagate along the axon. | |
| Saison 1 - épisode 41 | Synaptic Integration and Memory In addition to transmitting information, the nervous system must also be able to process it. This lecture covers how inputs to a typical neuron are... | |
| Saison 1 - épisode 42 | Sensory Function This lecture looks at the basic principles underlying sensory function; the mechanism by which animals obtain information from their environment. | |
| Saison 1 - épisode 43 | How Muscles Work Turning to the output side of cell function, Professor Nowicki examines muscles, describing the molecular basis for how muscle cells change their... | |
| Saison 1 - épisode 44 | The Innate Immune System How do animals defend themselves from injury or infection? We see how the nonspecific, or innate, immune response provides a general defense. | |
| Saison 1 - épisode 45 | The Acquired Immune System What happens if an infection can't be handled by nonspecific defenses? This is where the more specifically targeted and more efficient mechanisms... | |
| Saison 1 - épisode 46 | Form and Function in Plants I This lecture begins an examination of plant structure, development, and physiology, illustrating similarities and differences with analogous... | |
| Saison 1 - épisode 47 | Form and Function in Plants II We continue our study of plant form and function by looking at how homeostasis is maintained in plants and by examining the ways plants respond to... | |
| Saison 1 - épisode 48 | Behavior as an Adaptive Trait This lecture discusses the adaptive significance of the ways organisms respond to stimuli. Why are some behaviors inflexible and others not? | |
| Saison 1 - épisode 49 | Energy and Resources in Living Systems Starting with a review of previous material, Professor Nowicki sets the stage for the third major theme of the course,;Energy and Resources which... | |
| Saison 1 - épisode 50 | How Energy is Harnessed by Cells We look at the process by which cells obtain energy from a molecule called adenosine triphosphate |
