From Science in the Early Twentieth Century: An Encyclopedia:
Microbiology is the study of the nature and effects of microorganisms.
- Virology: Topic Page
Virology is the study of viruses and their role in disease.
- Anthrax: Topic Page
Acute infectious disease of animals that can be secondarily transmitted to humans. It is caused by a bacterium (Bacillus anthracis) that primarily affects sheep, horses, hogs, cattle, and goats and is almost always fatal in animals.
- Antibody: Topic Page
Protein molecule produced in the blood by lymphocytes in response to the presence of foreign or invading substances (antigens); such substances include the proteins carried on the surface of infecting micro-organisms.
- Bacteria: Topic Page
Microscopic single-celled organisms lacking a membrane-bound nucleus. Bacteria, like archaea, certain fungi, and viruses, are micro-organisms - organisms that are so small they can only be seen using a microscope.
- Common Cold: Topic Page
Acute viral infection of the mucous membranes of the nose and throat, often involving the sinuses. The typical sore throat, sneezing, and fatigue may be accompanied by body aches, headache, low fever, and chills.
- Immunity: Topic Page
Ability of an organism to resist disease by identifying and destroying foreign substances or organisms. Although all animals have some immune capabilities, little is known about nonmammalian immunity.
- Immunology: Topic Page
Branch of medicine that studies the response of organisms to foreign substances, e.g., viruses, bacteria, and bacterial toxins.
- Influenza: Topic Page
Or flu, acute, highly contagious disease caused by a virus; formerly known as the grippe. There are three types of the virus, designated A, B, and C, but only types A and B cause more serious contagious infections.
- Malaria: Topic Page
Infectious parasitic disease of the tropics transmitted by mosquitoes, marked by periodic fever and an enlarged spleen.
- Penicillin: Topic Page
Any of a group of chemically similar substances obtained from molds of the genus Penicillium that were the first antibiotic agents to be used successfully in the treatment of bacterial infections in humans.
- Plague: Topic Page
Term applied to any epidemic disease with a high mortality rate, but it usually refers to bubonic plague. This is a disease transmitted by fleas (carried by the black rat), which infect the sufferer with the bacillus Yersinia pestis.
- Rabies: Topic Page
Viral disease of the central nervous system that can afflict all warm-blooded creatures. It is caused by a lyssavirus.
- Staphylococcus: Topic Page
Any of the pathogenic bacteria, parasitic to humans, that belong to the genus Staphylococcus. The spherical bacterial cells (cocci) typically occur in irregular clusters [Gr. staphyle=bunch of grapes].
- Streptococcus: Topic Page
Any of a group of gram-positive bacteria, genus Streptococcus, some of which cause disease. Streptococci are spherical and divide by fission, but they remain attached and so grow in beadlike chains.
- Vaccination: Topic Page
Means of producing immunity against pathogens, such as viruses and bacteria, by the introduction of live, killed, or altered antigens that stimulate the body to produce antibodies against more dangerous forms.
- Virus: Topic Page
Parasite with a noncellular structure composed mainly of nucleic acid within a protein coat.
From Dictionary of Microbiology & Molecular Biology: Parisitology is the study of parasites.
- Parasite: Topic Page
Plant or animal that at some stage of its existence obtains nourishment from another living organism called the host. Parasites may or may not harm the host, but never benefit it.
- Schistosomiasis: Topic Page
Bilharziasis, or snail fever, parasitic disease caused by blood flukes, trematode worms of the genus Schistosoma. Three species are human parasites: S. mansoni,S. japonicum, and S. haematobium.
- Trypanosomiasis: Topic Page
Infectious disease caused by a protozoan organism, the trypanosome, which exists as a parasite in the blood of a number of vertebrate hosts. The three variations of the disease that predominate in humans are transmitted by an insect vector.
- Reproduction: Topic Page
The process by which a living organism produces other organisms more or less similar to itself.
- Asexual Reproduction: Topic Page
Reproduction that does not involve the manufacture and fusion of sex cells (gametes) from two parents.
- Embryo: Topic Page
Name for the developing young of an animal or plant. In its widest definition, the embryo is the young from the moment of fertilization until it has become structurally complete and able to survive as a separate organism.
- Fertilization: Topic Page
In sexual reproduction, the union of two gametes (sex cells, often called egg or ovum, and sperm) to produce a zygote, which combines the genetic material contributed by each parent.
- Placenta: Topic Page
Organ that attaches the developing embryo or fetus to the uterus (womb) in placental mammals (mammals other than marsupials, platypuses, and echidnas).
- Sperm: Topic Page
In biology, the male gamete of animals before fertilization in sexual reproduction.
From The Encyclopedia of Ecology and Environmental Management:
The theory and practice of describing the diversity of organisms and of ordering this diversity into a system of words, called classifications, that convey information concerning kinds of relationships among organisms.
- Cladistics: Topic Page
Method of biological classification that uses a formal step-by-step procedure for objectively assessing the extent to which organisms share particular characteristics, and for assigning them to taxonomic groups called clades.
- Kingdom: Topic Page
Primary division in biological classification. At one time, only two kingdoms were recognized: animals and plants. Today most biologists prefer a five-kingdom system, even though it still involves grouping together organisms that are probably unrelated.
- Porifera: Topic Page
[Lat.,=pore bearer], animal phylum consisting of the organisms commonly called sponges.