The Baltimore system of virus classification devised by virologist & Nobel laureate David Baltimore is based on the genomic nature of the viruses. The central theme of Baltimore system of virus classification is ‘all viruses must synthesize positive strand mRNAs from their genomes, in order to produce proteins and replicate themselves’. The precise mechanisms…
KEY CONCEPTS: A cell is the basic unit of life, as we understand it. Whilst the overall workings of all cells are very similar, there is no such thing as the conveniently termed ‘typical cell’ but cells within the two main groups of organisms, the prokaryotes (mainly bacteria) and the eukaryotes (higher animals and plants), have many chemical and physical features…
Bacteria are microscopic (very tiny) organisms that are unicellular (made up of a single cell). Bacterium is the term for a single bacteria. Evolution of Bacteria : These primitive organisms were among the first to appear on Earth; bacteria evolved roughly 3.5 billion years ago. The oldest-known fossils are those of bacteria-like organisms. Discovery of Bacteria:…
WHY did nature evolve cellular structures? In, I laid out a structural classification of cellular structures in nature, proposing that they fall into 6 categories. I argued that it is not always apparent to a designer what the best unit cell choice for a given application is . While most mechanical engineers have a feel for what structure to use for high stiffness…
Britannica Lists & Quizzes Wilfredo R. Rodriguez H. Think back to your high school biology class. Do you still remember the names and functions of all those little cell parts? A little foggy on the details, perhaps? Here’s a quick refresher course of some of the major eukaryotic organelles to keep your science skills sharp. It might come in handy for…
Ancient bacteria trapped in a state of suspended animation for 250 million years are the world s oldest living things, claim US scientists. The microbes are ten times older than any previously discovered living organism and may reopen the debate about the origins of life on Earth. The bacteria were found in salt crystals buried almost 609 metres (2, feet) below…
Amongst the different microorganisms inhabiting in the soil, bacteria are the most abundant and predominant organisms. These are primitive, prokaryotic, microscopic and unicellular microorganisms without chlorophyll. Morphologically, soil bacteria are divided into three groups viz Cocci (round/spherical), (rod-shaped) and Spirilla I Spirllum (cells with long…
Propionibacterium acnes bacteria are found deep in the hair follicles and pores of the skin, where they usually causes no problems. However, if there is an over-production of sebaceous oil, they grow, producing enzymes that damage the skin and cause acne. Credit: SCIENCE PHOTO LIBRARY/Getty Images Propionibacterium acnes thrive on the oily surfaces of the skin…
She said that despite these tests, the precise microorganism cannot be identified in up to half of the people who have pneumonia and when the person is severely ill and is not helped by initial therapy and doctors can try to obtain better samples, often by inserting a long flexible tube (bronchoscope) into the airways.The effective microorganism enhances the…
RELATIVE AMOUNTS OF BACTERIA AND FUNGI All soils contain both bacteria and fungi, but they may have different relative amounts depending on soil conditions. The general ways in which you manage your soil—the amount of disturbance, the degree of acidity permitted, and the types of residues added—will determine the relative abundance of these two major groups of…
It s time to discuss our very own special set of cellular goods. Centrioles The centriole is a small, barrel-shaped tube composed of protein located in the cytoplasm. Barrels of fun: The centriole s main function is to aid in cell division and in the spatial arrangement of structures within the cell. Less is known about the function of centrioles than many of…
A. INTRODUCTION TO MICROBIOLOGY Fundamental Statements for this Learning Object: 1. Microorganisms are typically too small to be seen with the naked eye. 2. Bacteria, fungi, viruses, protozoa, and algae are the major groups of microorganisms. 3. The vast majority of microorganisms are not harmful but rather beneficial. 4. Microbiota refers to all of the microorganisms…
