Timeline of evolution and Evolutionary history of life The ancestors of modern bacteria were unicellular microorganisms that were the first forms of life to appear on Earth, about 4 billion years ago. For about 3 billion years, most organisms were microscopic, and bacteria and archaea were the dominant forms of life. Here, eukaryotes resulted from the entering of ancient bacteria into endosymbiotic associations with the ancestors of eukaryotic cells, which were themselves possibly related to the Archaea. Later, some eukaryotes that already contained mitochondria also engulfed cyanobacteria -like organisms, leading to the formation of chloroplasts in algae and plants.
Good Definition and Nature of the Work Microbiologists are biological scientists who study organisms so small that, generally, they can only be seen with a microscope.
These microorganisms include bacteria, algae, yeasts, fungi, protozoa, viruses, and other microscopic forms of life. Microbiologists isolate and make cultures of microorganisms, identify their characteristics, and observe their reactions to chemicals and other kinds of stimuli.
They also study how microorganisms develop and reproduce as well as their distribution in nature. Many microbiologists work for universities, where they teach and do research. Others work at medical centers or in private industry.
Some work for government agencies. Although their jobs have different aspects and responsibilities, most microbiologists do some research or laboratory work. They use special equipment to study microorganisms including light microscopes, electron microscopes, centrifuges, glass tubes, slides, and computers.
They are often assisted by biological technicians.
Microbiology is a broad field that includes the study of viruses as well as microscopic organisms found in all kingdoms of life: Some microbiologists specialize in one type of microorganism. For example, bacteriologists concentrate on bacteria and virologists study viruses.
Microbiologists work in several areas. Many do basic research to increase knowledge about the life processes common to microbes. Their work helps to answer basic questions such as those pertaining to the use of food and oxygen in cells. Other microbiologists are employed in medicine. Medical microbiologists study the relationship between microorganisms and disease.
They isolate and identify disease-producing organisms and study their distribution. They also study the ways that the organisms enter the bodies of humans and animals, establish themselves, and cause disease.
Other medical microbiologists study the Microbiologists study microscopic forms of life such as bacteria, algae, yeast, fungi, protozoa, and viruses.
Some are concerned with the role of viruses in cancer. Others help to develop new ways to treat and prevent disease. Microbiologists are also employed in the related field of public health. They work to combat problems such as outbreaks of epidemics, food poisoning, and the pollution of air and water.
For example, public health microbiologists test blood samples sent in by physicians to see whether patients have a communicable disease. They also test drinking water, milk supplies, and other substances that can affect the health of the general public.
Other fields in which microbiologists work include agriculture, marine microbiology, and industry. Agricultural microbiologists study the microorganisms found in soil and their effects on plant growth.
Marine microbiologists seek ways to control the growth of harmful bacteria in oceans and rivers. Industrial microbiologists work in a variety of industries, including food processing, chemicals, and drugs.Biological Weapons. Biological weapons are toxic materials produced from pathogenic organisms (usually microbes) or artificially manufactured toxic substances that are used to intentionally interfere with the biological processes of a host.
Traces of life are nearly ubiquitous on Earth. However, a central unresolved question is whether these traces always indicate an active microbial community or whether, in extreme environments, such as hyperarid deserts, they instead reflect just dormant or dead cells.
Bacteria is one of these domains, while the others are eukarya, composed of organisms that have nucleated cells, and archaea, composed of unicellular prokaryotes, many of which have evolved to.
Why are viruses important? Viruses cause many diseases of international importance. Amongst the human viruses, smallpox, polio, influenza, hepatitis, human immunodeficiency virus (HIV-AIDS), measles and the SARS coronavirus are particularly well known. Biological weapon, also called germ weapon, any of a number of disease-producing agents—such as bacteria, viruses, rickettsiae, fungi, toxins, or other biological agents—that may be utilized as weapons against humans, animals, or plants.
Microbiologist Job Description, Career as a Microbiologist, Salary, Employment - Definition and Nature of the Work, Education and Training Requirements, Getting the Job.