Microbe Scavenger Hunt Name _______________________________
Directions: You are going to go online to find the latest information about microbes from the American Society for Microbiology at http://archives.microbeworld.org/microbes/.
Go to my webpage at www.cwcboe.org > School (GCMS) > Staff (Isabella D’Agostino) > Viruses and Bacteria Page > Microbe Scavenger Hunt 1.Use the hyperlinks within the document to navigate the site and complete the statements that follow.
What is a Microbe?
1. Microbes are ___________________ organisms so tiny that ________________ can fit into the eye of a needle.
2. Microbe fossils date back more than ______________________ to a time when the earth was covered with oceans.
3. Without microbes, we couldn’t _______ or __________.
4. Microbes are in the _______ we breathe, the ____________ we walk on, the ______________ we eat – they’re even inside ______!
5. We couldn’t _____________ food without them – animals couldn’t, either.
6. Without microbes, plants couldn’t ___________, garbage wouldn’t ____________, and there would be a lot less _______________ to breathe.
Types of Microbes
(Click Types of Microbes on the left-hand menu.)
1. Microbes can be divided into six main types:
(Click Bacteria on the left-hand menu.)
1. Bacteria consist of only a single ________________.
2. Bacteria have been found that can live in temperatures above the _________________ point and in cold that would ____________ your blood.
3. There’s even a species of bacteria – Deinococcus radiodurans – that can withstand blasts of radiation 1,000 times greater than would kill a human being.
4. Bacteria fall into a category of life called the ____________________.
5. Prokaryotes’ genetic material or DNA is not enclosed in a cellular compartment called the _______________________.
How Long They’ve Been Around
6. Bacteria are among the earliest forms of life that appeared on Earth __________ of years
7. Scientists think they helped shape and change the young planet’s environment, eventually
creating atmospheric ______________ that enabled other, more complex life forms to
8. Many believe that more complex ___________ developed as once free-living bacteria took up residence in other cells, eventually becoming the ___________ in modern complex cells.
9. The __________________ that make energy for your body cells is one example of such an organelle.
What They Look Like
(Click What They Look Like on the left-hand menu.)
1. There are ____________________ of species of bacteria, but all of them are basically one of _______ different shapes. Some are ________ or stick-shaped and called _______________.
2. Others are shaped like little balls and called _____________.
3. Others still are helical or _________________ in shape, like the Borrelia pictured at the top of this page.
4. Some bacterial cells exist as _________________while others ____________ together to form pairs, chains, squares, or other groupings.
Where They’re Found
(Click Where They’re Found on the left-hand menu.)
1. Bacteria live on or in just about every __________________ and environment on Earth from soil to water to air, and from your _____________ to arctic ___________ to ________________ vents.
2. Each square centimeter of your skin averages about ____________________ bacteria.
3. A single teaspoon of topsoil contains more than ____________________ bacteria.
What They Eat
(Click What They Eat on the left-hand menu.)
1. Some bacteria are __________________________ – they can make their own food from sunlight, just like plants.
2. Also like plants, they give off ____________________.
3. Other bacteria absorb food from the material they live on or in. Some of these bacteria can live off unusual “foods” such as ______________ or sulfur.
4. The microbes that live in your gut absorb __________________ from the digested food you’ve eaten.
How They Move
(Click How They Move on the left-hand menu.)
1. Some bacteria move about their environment by means of long, whip-like structures called _____________________.
2. Other bacteria secrete a ______________________ layer and ooze over surfaces like __________________.
3. Others are fairly ________________________.
Archaea and Other Extremists (Click Archaea on the left-hand menu.)
Types of Archaea
1. There are three main types of archaea:
2. Archaea look a lot like _________________. So much so that until the late 1970s, scientists assumed they were a kind of “weird” bacteria.
3. Then microbiologist Carl Woese devised an ingenious method of comparing ______________ information showing that they could not rightly be called bacteria at all. Their genetic recipe is too different.
4. Archaeans are single-celled creatures that join bacteria to make up a category of life called the _______________________.
5. Prokaryotes’ genetic material, or DNA, is not enclosed in a central cellular compartment called the ________________.
6. Bacteria and archaea are the only ____________________.
7. All other life forms are _______________________________, creatures whose cells have nuclei.
8. Archaeans are among the __________________ forms of life that appeared on Earth
billions of years ago.
9. It’s now generally believed that the archaea and bacteria developed separately from a
___________ ancestor nearly 4 billion years ago.
10. Millions of years later, the ancestors of today’s eukaryotes split off the archaea. So historically, archaeans are more closely related to _________ than they are to bacteria.
What They Look Like (Click What They Look Like on the left-hand menu.)
Some archaea look like little __________ or tiny balls, and some even get around like bacteria using long hair- or whip-like appendages called ________________ that stick out of their cell walls.
1. Like bacteria, archaea lack a true __________________.
Where They’re Found (Click Where They’re Found on the left-hand menu.)
Archaea comes from the Greek word meaning “_______________.”
1. An appropriate name, because many archaea thrive in conditions mimicking those found more than __________________ years ago.
2. Back then, the earth was still covered by oceans that regularly reached the boiling point — an extreme condition not unlike the __________________ vents and ______________ waters where archaea are found today.
3. In addition to superheated waters, archaea have been found in acid-laden ____________ around old mines, in frigid _________________ ice and in the super-salty waters of the ______________________.
What They Eat (Click What They Eat on the left-hand menu.)
1. Archaeans dine on a variety of substances for energy including _______________ gas, carbon _________________ and sulfur.
2. One type of salt-loving archaean uses _________________ to make energy, but not the way plants do.
3. This archaean has a light-harvesting pigment in the ________________ of its cell.
4. This pigment, called ____________________, reacts with light and enables the cell to make __________, an energy molecule.
Most Notable Bacteria for Research
• Bacillus anthracis causes anthrax, a deadly disease in cattle and a potential bioweapon against humans
• .Brucella abortus causes breeding losses in livestock.
• Cyanobacteria (formerly known as blue-green algae) live in water, where they produce large amounts of the oxygen we breathe.
• Escherichia coli (a.k.a. E. coli) lives in the gut, where it helps digest food and produces Vitamin K. The “bad” strain of E. coli O157:H7 causes severe foodborne sickness.
• Lactobacillus bulgaricus helps turn milk into cheese, yogurt, and other dairy products.
• Bacterium tuberculosism Mycoba causes tuberculosis, a major killer from the past that has recently resurged with the advent of AIDS.
• Rhizobia convert free nitrogen into a form that the plants can use in order to grow.
• Staphylococcus (a.k.a. staph) can cause serious infections and is one of the most drug-resistant bacteria.
• Streptococcus pneumoniae causes strep throat, meningitis, and pneumonia.
• Streptomyces griseus makes the antibiotic streptomycin.
• Thermus aquaticus is a heat-loving bacterium from which scientists got the enzyme Taq polymerase that makes routine DNA fingerprinting and gene sequencing possible.
• Mycobacterium tuberculosis or Mycobacterium leprae
• E. coli
• Bacillus or Clostridium
• Streptococcus pneumonia
• gram-negative bacterium
• spirochete bacterium pleomorphic, Mycoplasma pneumonia