DNA Viruses - Biology Encyclopedia
Viruses can be classified based on proteins encoded within the viral genetic material or genome. Viruses with deoxyribonucleic acid (DNA) genomes are called DNA viruses.
Doctor, Family Practice - Biology Encyclopedia
A family practice doctor is the primary health care professional responsible for treating people for most conditions. Family physicians work in private offices, group practices, and hospitals, caring for every family member from before birth until the time of death.
Doctor, Specialist - Biology Encyclopedia
A medical specialist focuses on diagnosis and treatment of a particular organ or body system, a specific patient population, or a particular procedure. Medical care of humans is a complicated task due to the many different organ systems that comprise the human body.
Drug Testing - Biology Encyclopedia
Drug testing refers to the process of detecting "drugs" in human or animal specimens. Drug testing may be performed in the contexts of sports, workplace safety, therapeutic drug monitoring, forensics, toxicology, and drug abuse prevention.
Dubos, René - Biology Encyclopedia
In 1939 René Dubos launched the antibiotic era by reporting the discovery of gramicidin after the first systematic search for antimicrobial agents. Following this discovery he warned of microbial resistance to antibiotics, completed innovative studies of tuberculosis, expanded investigations into the nature of disease and, ultimately, examined the question of health.
Echinoderm - Biology Encyclopedia
The echinoderms (echino means "spiny;" derm means "skin") are large, conspicuous, entirely marine invertebrates. Today, this group inhabits virtually every conceivable oceanic environment, from sandy beaches and coral reefs to the greatest depths of the sea.
Ecological Research, Long-Term - Biology Encyclopedia
Many ecological studies last just one or a few years. There are many reasons for this.
Ecology - Biology Encyclopedia
Ecology is the study of how plants, animals, and other organisms interact with each other and with their environment, or "home." The word "ecology" comes from the Greek word oikos, which means "home." Ecology is also the study of the abundance and distribution of organisms. An ecologist, for example, might try to find out why a species of frog that used to be common is now rare, or why fir trees are rare in a dry pine forest but common in a moister habitat.
Ecology, History of - Biology Encyclopedia
Ecology descended from a tradition of natural history beginning in antiquity. What has been called protoecology is seen in the writings of Carolus Linnaeus, a Swedish botanist, who, in the eighteenth century, wrote of interactions of plants and animals, which he called The Economy of Nature.
Ecosystem - Biology Encyclopedia
An ecosystem is all the living organisms in an area along with the nonliving, or abiotic, parts of their environment. The abiotic parts of an ecosystem include physical substances such as soil, air, and water; forces such as gravity and wind; and conditions such as temperature, light intensity, humidity, or salinity.
Electron Microscopy - Biology Encyclopedia
The light microscope (LM) is limited in its resolution to about 0.25 micrometers. If two objects are closer together than that, they blur together and cannot be distinguished by the LM.
Electrophoresis - Biology Encyclopedia
Electrophoresis is one of the most important techniques used by molecular biologists. To name only a few applications, deoxyribonucleic acid (DNA) electrophoresis is used to map the order of restriction fragments within chromosomes, to analyze DNA variation within a population by restriction fragment length polymorphisms (RFLPs), and to determine the nucleotide sequence of a piece of DNA.
Emergency Medical Technician - Biology Encyclopedia
An emergency medical technician (EMT) is a person who delivers the initial medical treatment to persons in crisis situations. Traditionally, EMTs are part of the medical team that travels by ambulance or helicopter to the site of the emergency situation.
Endangered Species - Biology Encyclopedia
Endangered species are species of plants or animals (or other life forms such as fungi) that are threatened with extinction. As well as being a biological term, "endangered" has a formal political meaning: nations, states, and other organizations evaluate the status of species and determine which are in the greatest danger of going extinct; these species are designated as endangered species.
Endocrine System - Biology Encyclopedia
The endocrine system is the interacting group of glands that secrete hormones, helping to control cells and organs throughout the body. How do cells and organs at different locations in the body communicate with each The endocrine organs in the human body.
Endocytosis - Biology Encyclopedia
The ability to internalize material from outside the cell is important for several cellular processes including the ingestion of essential nutrients, removal of dead or damaged cells from the body, and defense against microorganisms. Eukaryotic cells internalize fluid, large and small molecules, and even other cells from their surroundings by a process called endocytosis.
Endoplasmic Reticulum - Biology Encyclopedia
The endoplasmic reticulum (ER) is a series of interconnected membranes or flattened sacs adjacent and connected to the nuclear membrane. The ER comes in two different morphological forms: smooth endoplasmic reticulum (sER) and rough endoplasmic reticulum (rER).
Entomologist - Biology Encyclopedia
Entomologists study insects and their relatives and use their findings to help people, animals, and plants. Of the many branches of entomology, one of the most interesting is that related to forensics.
Environmental Health - Biology Encyclopedia
Environmental health describes the effects of civilization, culture, personal habits, pollution, population growth, and travel on human health. It is a new science that measures a variety of factors leading to acquired and congenital diseases.
Enzymes - Biology Encyclopedia
Enzymes are incredibly efficient and highly specific biological catalysts. In fact, the human body would not exist without enzymes because the chemical reactions required to maintain the body simply would not occur fast enough.
Epidemiologist - Biology Encyclopedia
An epidemiologist is a scientist who studies how diseases interact with populations. Most epidemiologists study the relationships between germs and people, but some investigate animal or plant diseases.