Structure: Like many other protists, the structure of Amoeba proteus is relatively simple. It is a single celled organism that appears transparent and gelatin like – with an arguably “forever” changing shape, with a nucleus and membrane bound organelles (such as food vacuoles, contractile vacuoles, golgi apparatus, mitochondria etc.). As mentionned above, Amoeba proteus…
Learning Objectives Summarize Koch’s postulates and molecular Koch’s postulates, respectively, and explain their significance and limitations Explain the concept of pathogenicity (virulence) in terms of infectious and lethal dose Distinguish between primary and opportunistic pathogens and identify specific examples of each Summarize the stages of pathogenesis Explain…
Viruses – Pages 475-483 Viruses Not living Don’t grow or develop No respiration Only reproduce within a host (can’t do it alone MUST have a host) Virus multiply through the lytic cycle where the virus attacks the host, injects it nucleic acid into the host, and then spreads or bursts from the host. Virus Structure Structure = Made up of (1) protein coat- capsid (located…
(Smithsonian.com) What s the difference between bacteria and viruses? You asked us, what s the difference between bacteria and viruses? You see, bacteria are microscopic. They live just about everywhere, including extreme environments like hot springs and radioactive waste. Now, you can wag a finger at bacteria for things like ear infections and strep throat. But…
Bacteria are the oldest and most abundant life form on Earth. These microscopic, single-celled organisms live in all environments - including in and on the human body. A study published in May 2016 in the Proceedings of the National Academy of Sciences of the U.S.A. estimated there may be as many as 1 trillion different types of bacteria. Most bacteria are harmless…
Chromosomes are the thread-like structure found in the nuclei of both animal and plant cells. They are made of protein and one molecule of deoxyribonucleic acid (DNA). As the genetic material passes from parents to child, the chromosomes are responsible for containing the instructions that make the offspring unique while still carrying traits from the parent. In most…
Plasmids are sometimes called vectors , because they can take DNA from one organism to the next. Not all vectors are plasmids, however. We commonly use engineered viruses, for example bacteriophage lambda, which can carry large pieces of foreign DNA. Why do we use the word vector,which we ve been trying to forget ever since we took Physics 100? The word has a connotation…
Ideas about cell structure have changed considerably over the years. Early biologists saw cells as simple membranous sacs containing fluid and a few floating particles. Today s biologists know that cells are infinitely more complex than this. There are many different types, sizes, and shapes of cells in the body. For descriptive purposes, the concept of a generalized…
Coughing and sneezing. Contact with infected people, especially through kissing and sex. Contact with contaminated surfaces, food, and water. Contact with infected creatures, including pets, livestock, and insects such as fleas and ticks. Microbes can also cause: Acute infections, which are short-lived. Chronic infections, which can last for weeks, months, or a lifetime…
In Simple words, it can be described as it is “wall” it gives Protection, Support to the inner Cellular parts or Organelles of a bacteria, also it gives a defined shape to it. A Image of Bacterial cell (Image Courtesy:Google) In Technical terms, there are some points that can be added to it, they are Cell wall of a Bacteria provides a defined Shape to it It protects…
Centrioles function as the major micro tubule organizing centers which is an important event in two major cellular processes - cell division and cilia and/or flagella formation. Given below is a description of the precise role of centrioles in each of these processes. Cell Division The pair of centrioles within a cell duplicates, and the two pairs migrate to opposite…
This lab activity uses a controlled experiment to demonstrate different rates of decomposition for a variety of man-made and natural materials. Microorganisms are ubiquitous in the environment, where they have a variety of essential functions. Many microbes are uniquely adapted to specific environmental niches, such as those that inhabit the Dead Sea (Halobacterium)…
The illustration shows a generalised bacterium with many of the main components illustrated. No real organism would have all of these features. The image above is 400 pixels across and the original is 5, 438 pixels across. CELL WALL The top half of the diagram shows a Gram +ve bacterium with its thick peptidoglycan outer wall closely apposed to the inner plasma membrane…
These are three bacterial motors with different torque (units of torque are piconewton nanmometres, pN nm). Credit: Morgan Beeby/Imperial College London Many bacteria swim using flagella - long tails that are attached to tiny motors made of proteins, just tens of nanometres wide. These motors spin the flagella, which work as nanoscale propellers to drive the bacterium…
