Microbiology Worksheet The World of Microbes A Vocabulary warm-up. Match the types of microbes with their definitions. 1 bacteria a) single-celled organisms. They come in many different shapes and sizes ranging from an Amoeba which can change its shape to Paramecium. They live in a wide variety of moist habitats including fresh water, marine environments and the soil. 2 archaea b) live in fresh or sea water where they can either be free-floating (planktonic) or attached to the bottom. Some can grow on rocks, soil or vegetation as long as there is enough moisture. A few form very close partnerships with fungi to form lichens. 3 fungi c) the smallest of all the microbes. They are said to be so small that 500 million could fit on to the head of a pin. They are unique because they are only alive and able to multiply inside the cells of other living things. 4 protozoa d) single celled microbes. The cell structure is simpler than that of other organisms as there is no nucleus or membrane bound organelles. Instead their control centre containing the genetic information is contained in a single loop of DNA. 5 algae e) can be spherical, rod, spiral, lobed, rectangular or irregular in shape. Some exist as single cells, others form filaments or clusters. Until the 1970s this group of microbes was classified as bacteria. 6 viruses f) can be one-cell or very complex multicellular organisms. A group called the decomposers grow in the soil or on dead plant matter where they play an important role in the cycling of carbon and other elements. B The Dengue Virus A Matching up: 1 find a a cure 2 engulf b a virus 3 prevent c an infection 4 get d sick 5 beat out e a disease organism 6 kill out f a pathogen 7 infect g humans 8 bind to h a host cell 1 The dengue virus infects about ______ people each year. A 100 million B 10 million C 110 million 2 There is currently _____vaccine available to prevent this infection. A only one B no C a 3 The common name for this disease is_____ fever. A broke-bone B brake-bone C broken-bones 4 The body __________rises to kill the pathogens. A temperature B heat C fever 5 Lipid bilayer coating the virus’ genome is similar to a ____________ A bundle B bubble C bindle 6 On the outer _______ of the virus are proteins which are binding to host blood cells A part B surface C layer 7 The virus gets engulfed into the phagocytic ___________ A vehicle B vesiculum C vesicle 8 Mosquitos spreading the dengue virus appeared in Florida in __________ A 2008 B 2009 C 2010 What are some precautions against the dengue virus? Turbidimetry One of the simplest ways to ____(1) the density of a bacterial culture is to use a spectrophotometer to quantify the ____ (2) of turbidity, or cloudiness, in the culture. Bacterial cells are within a size range that causes them ___(3) slightly scatter light. The denser the culture, ____(4) more light is scattered, and the less light reaches the phototube of the spectrophotometer. In fact, turbidity is more closely related to cell biomass (cell dry weight) ____(5) to the number of cells present. In dilute samples, absorbance is directly proportional to biomass. In dense cultures, light is likely to ___ (6) deflected from more than one cell, ___(7) some light will be redirected back to the photocell. Because factors ____(8) as cell size, cell density, and instrument characteristics influence the relationship between cell density and absorbance, a standard curve relating cell concentrations to absorbance is usually used ____(9) converting absorbance data to more useful quantities. Turbidimetry is generally done at wavelengths around 630 nm to minimize absorbance ___(10) the medium because most bacterial growth media are brown or brownish-yellow. 1 A count B determine C deliver D outnumber 2 A statistics B amount C number D degree 3 A to B in C for D at 4 A some B a C the D and 5 A as B than C even D then 6 A run B turn C have D be 7 A so B while C because D unless 8 A so B than C such D some 9 A as soon as B when C after D although 10 A with B by C from D for Grammar Point Relative clauses