unit 5 ~ learning guide name: - bc learning...

BCLN BIOLOGY 11 – Rev July 2014

of 35

Unit 5 ~ Learning Guide Name: _______________ INSTRUCTIONS Using a pencil, complete the following notes and questions as you work through the related lessons. You are required to have this package completed BEFORE you write your unit test. Do your best and ask questions about anything that you don't understand BEFORE you write the unit test. 5.1 NOTES: BACTERIAL CLASSIFICATION Discovery of Bacteria It had long been suspected that ____________________________________________ which are too small to be seen with naked eye. But ___________________________ _____________________________________________________. A Dutch scientist, _____________________________________________________ (1673), was the _________________________ ___________________________________. He used a simple microscope to describe bacteria and protozoa with accurate drawings and descriptions and called these small creatures animalcules. He first observed small creatures in rain water, then confirmed these in saliva, vinegar, infusions and other substances. The progress in understanding the nature and importance of these tiny organisms has been slow. The existence of microbes was further confirmed by ___________________ _________________________________. Pasteur went on to make _______________ ________________________________________________________________________________________________________________. His main achievements are the development of vaccines for anthrax disease, fowl cholera and rabies. He also made significant contributions in development of the pasteurization process and development of fermentation industries. _____________________________________________ ________________________________________________________________. .


of 35

The Prokayotes The Kingdom prokaryotae (often referred to as _____________________) consists of organisms with ___________________ _________________. Prokaryotic cells _________________________________________________________________________________________________________________ that typify the eukayota. In Greek the word ___________________ ____________________ _________ and ____________________________________________. Traditional classifications have placed the archea and bacteria into this single taxonomic kingdom due to their morphological similarity. In fact the two groups are extremely different, as different from each other biochemically as eukaryotes are from either group. Microbiologists now recognize that there are _____________________________________________________________: a much smaller division called the Archaebacteria (Greek for _________________________________________ __________________________________________), a larger group called Eubacteria (Greek for _________ ______________________), and the Eukaryotes. Their small size, ability to rapidly reproduce (for example, the intestinal bacterium E. coli can reproduce by binary fission every 15 minutes), and diverse habitats/modes of existence make _________________________________________________________ ______________________________________________________________. Bacteria are wide spread in their occurrence. They are ________________________________ _________________________________________________________________________________________________________________________________________. Their kind and number vary according to locality and environmental conditions. Some bacteria are always present and contribute towards the natural flora. Others are present in specific environments such as hot springs, alkaline/acidic soil, highly saline environments, in highly polluted soils and waters.

Archaebacteria

The name comes from the root "archae" which means ancient. Archaebacteria are considered among _______________________________________________________ __________________________________________________. The archeans are life's extremists, occupying environments that "normal" organisms find too harsh such __________________________________________________________. They do not need oxygen or light to survive.


of 35

There are three groups of Archaea:

1. The _______________________________________ live under anaerobic environments (e.g., marshes) where they produce methane.

2. _________________________________ require high salt concentrations (such as in Utah's Great Salt Lake).

3. __________________________________ live under hot, acidic environments (like those found in geysers)

Eubacteria The Eubacteria and blue-green bacteria (once referred to as blue-green algae), or cyanobacteria are the _________________________________________________ __________________________. The name comes from the root "eu" which translates as ____________________. They are the most common forms of bacteria. There are approximately 12 different phyla. ___________________________________________ _____________________________________________________________________. .


of 35

Classifying Bacteria Bacteria can are classified by a number of different criteria: Most bacteria come in one of three different shapes. Some bacteria tend to organize into groups.

Term Describing Bacterial Shape

Picture of Bacterial

Shape

Prefix Describing

Bacterial Arrangement

Picture of Bacterial

Arrangement

1. _______________ = _______________

1. _______________ = _______________ e.g. diplococci are pairs of spherical shaped bacteria

2. _______________ = _______________

2. _______________ = _______________ e.g. streptococci are chains of spherical shaped bacteria

3. _______________ = _______________

3. _______________ = _______________ e.g. staphylococci are clusters of spherical shaped bacteria


of 35

Classifying Bacteria by Staining The _______________________________ is the most important staining procedure in microbiology. It is _______________________________________________________ _______________________________________________________________________________________________________. Hence, it is a differential stain. Gram staining involves a four-part process, which includes:

1. crystal violet 2. the primary stain iodine 3. the mordant a decolourizer made of acetone 4. alcohol safranin, the counterstain.

Gram negative and gram positive organisms are distinguished from each other ________________________________________________________________. These differences affect many aspects of the cell, including the way the cell takes up and retains stains. ______________________________________________________________, which is then fixed in the cell with the iodine mordant. This forms a crystal-violet iodine complex which remains in the cell even after decolorizing. It is thought that this happens because the cell walls of gram positive organisms include a _____________________________ protein-sugar complexes called __________________________. This layer makes up 60-90% of the gram positive cell wall. Decolorizing the cell causes this thick cell wall to dehydrate and shrink, which closes the pores in the cell wall and prevents the stain from exiting the cell. At the end of the gram staining procedure, ______________________________________________ ______________________________________________________________________


of 35

Gram negative cells also take up crystal violet, and the iodine forms a crystal violet- iodine complex in the cells as it did in the gram positive cells. However, ___________ _____________________________________________________________________________________________________________________. Peptidoglycans are present in the cell walls of gram negative organisms, but they only comprise 10-20% of the cell wall. Gram negative cells also have an outer layer which gram positive organisms do not have; this layer is made up of lipids, polysaccharides, and proteins. Exposing gram negative cells to the decolourizer dissolves the lipids in the cell walls, which allows the crystal violet-iodine complex to leach out of the cells. This allows the cells to subsequently be stained with safranin.________________________________ _________________________________________________________________________________________________________________________________________. Classifying Bacteria by Nutrition Bacteria are classified on the basis of their method of ____________________ ______________________. Traditional classifications include ___________________ __________________________________________________________________________________________________________________________________________________________________________ groups.

1. Chemosynthetic Bacteria - __________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________

• Example: Pseudomonas aeruginosa

2. Photosynthetic Bacteria - ____________________________________________ ________________________________________________________________. Cyanobacteria are the major group of photosynthetic bacteria. Some early cyanobacteria may have formed the ___________________________________ ________________________________, transforming our planet from one with an oxygen-free atmosphere, to the modern one that has a significant amount of oxygen present.

• Example: Heliobacteria from soil.

3. Saprophytic bacteria are heterotrophic bacteria that ______________________ _______________________________________________________________________________________________________________________________________________________________________________________

. 4. Parasitic bacteria are heterotrophic bacteria that _________________________

_______________________________________________________________.

http://www.biology-online.org/dictionary/Heterotrophic


of 35

5. Other Bacteria are classified as ____________________________. Decomposers play an important role in nature as they __________________________________. They are an important part of the food chain.

In summary, bacteria use all modes of nutrition. Some bacteria are autotrophic (able to produce their own energy) by photosynthesis and others by chemosynthesis. Most types of bacteria however, are heterotrophic by absorption. __________________________ ______________________________________________________________________________________________________________________________________________________________________________________________________. Others absorb nutrients from other living things and are known as parasites. 5.1 PRACTICE: BACTERIAL CLASSIFICATION

1. Recent classification schemes have determined there are three domains of life:

a. What are these domains called? (3 marks)

b. Which if these domains contain bacteria? (2 marks)

2. What distinguishes the domains that contain bacteria from the one that does not? Hint: think cellular structure. (2 marks)


of 35

3. Please classify each of the following bacteria using the terms gram positive, gram negative, staphylo-, strepto-, diplo-, -cocci, -bacilli, -spirilli. (12 marks)

Shape/Organization Gram Stain

Colour Classification

pink

Example: gram negative, monospirillum

*note: mono = one = individual bacteria

purple

purple

pink

pink

4. A gram positive bacteria is likely to have a great deal more

_____________________________________________ in its cell wall than a gram negative bacteria and thus, it will bind to and retain the Gram stain better. (1 mark)

5. Chemosynthetic bacteria are said to be ________________________ because they can produce energy and organic compounds for themselves, whereas most other bacteria are ____________________________ as they obtain energy and organic compounds by feeding off of other living things. (2 marks)


of 35

5.2 NOTES: BACTERIAL STRUCTURE ________________________________________________________________ - but don't let their small size and seeming simplicity fool you. They are an amazingly complex and fascinating group of organisms. Bacteria, since they are prokaryotes, _______________________ ______________________________________________________________________________________________________ that normally occur in a chloroplast or mitochondrion of eukaryotes will _______ _________________________________________________________________. Bacterial __________________________ _______________ and arrayed in a region of the cell known as the ______________. Scattered within bacterial cytoplasm are numerous _________________________ _____________________________________________ which are often used to carry foreign DNA into other bacteria for recombinant DNA engineering. The ________________________________________________________, the structures where proteins are assembled. All bacteria also have a _________________________ _______________________________, which is usually surrounded by a __________ _______________________________________________.


of 35

Bacterial Structure Associated Function

plasmid

_____________________________

capsule

________________________________________________ made up of polysaccharides (complex sugars. _________________________ ______________________________________ and protects it from drying out

cell wall

gives cell its shape and surrounds the cytoplasm _________________________________________________________

plasma membrane

a layer of phospholipids and proteins that allows certain materials into and out of the cell

ribosome

Only type of cell organelle found in bacteria. Small factories that translate the genetic code into proteins.

fimbriae

Small hair-like projections that emerge from the cell membrane. _________________________________________________________ ____________________________________________

cytoplasm

Or protoplasm, this is where the functions of cell growth, cellular metabolism and replication are carried out. It is a gel-like material that is composed of water, enzymes, nutrients, wastes and gasses and cell structures such as the ribosomes, chromosomes, and plasmids.

nucleoid

A region of the cytoplasm where the chromosomal DNA is located

flagella

Hair-like structures that ___________________________________. Not all bacteria have flagella.


of 35

Endospores Bacteria = _______________________________ ________________________________________ Microorganisms sense and adapt to changes in their environment. When favored nutrients are exhausted, some bacteria may become motile to seek out nutrients, or they may produce enzymes to exploit alternative resources. _______________ ________________________________________________________________________________________________________________________. This complex developmental process is ______________________________ _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________.Endospores can survive environmental assaults that would normally kill the bacterium. These stresses include ___________________________________________________ _________________________________________________________________. The extraordinary resistance properties of endospores make them of particular importance because they are not readily killed by many antimicrobial treatments. A variety of different microorganisms form spores or cysts, but the endospores of bacteria are by far the most resistant to harsh conditions.


of 35

5.2 PRACTICE: BACTERIAL STRUCTURE

1. Please draw a simplified diagram of a bacteria cell being sure to include and label the structures listed below. Please include a brief description of the structure's function beside the label. Please be neat. (10 marks)

o nucleoid o plasmid o cytoplasm

o cell wall o fimbriae o ribosomes

o flagella o capsule o plasma

membrane


of 35

5.3 NOTES: BACTERIAL REPRODUCTION Binary Fission ________________________ is the ________________________________________________________ by division into two approximately equal parts. This method of cellular reproduction occurs only in prokaryotes (bacteria and archaeans).

As one might expect, the volume of the two daughter cells produced is initially half that of the parent cell before the division. But each daughter cell does contain a complete copy of the parental chromosome.

Before fission can occur, ________ ____________________________ ____________________________, which is circular. Each chromosome then affixes itself to the cell membrane. As the cell stretches out during division, the two chromosomes move apart, and one passes into each of the two daughter cells.

The actual physical division of the cell into two compartments occurs when __________ _____________________________________________________________________________________________________________ across the middle of the cell.


of 35

Exchange of Genetic Information _________________________________________________________________________________________________________. When bacteria exchange DNA it has a similar effect to ____________________________ as there is a _________________. ___________________________________________________________. There are three ways in which bacteria exchange DNA.

1. __________________________ - male cell passes DNA to the female cell by means of a conjugation tube i.e., sex pilus.

2. _________________________ - bacterium takes up DNA released by dead bacteria.

3. ______________________________ - bacteriophages carry DNA from one cell to another


of 35

5.3 PRACTICE: BACTERIAL REPRODUCTION

1. Please identify which process in being represented by each picture below (transduction, binary fission, conjugation, and transformation) and then provide a brief description of the process in the box beside the picture. (8 marks)

Various Processes that Affect the Genetic Composition of Bacteria


of 35

5.4 NOTES: BACTERIAL METABOLISM The diversity of prokaryotes is expressed by their _____________________________ __________________________________________________________________, and this feature allows prokaryotes to flourish in all habitats on earth. Bacteria have been found that can live at ____________________________________________ and in those that would ______________________________________. They "eat" __________________________________________________________________________________________________________. There is even a species of bacteria that can withstand blasts of radiation 1,000 times greater than those that would kill a human being. Most bacteria are __________________________________________. These bacteria ____________________________________________________. These bacteria utilize cellular respiration to produce energy. Cellular Respiration is the breakdown of sugar molecules with the use of oxygen to release energy.

C6H12O6 + 6O2 --------> 6 H2O + 6 CO2 + Energy Some bacteria are called ________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________________________________________

a. Photosynthesis is __________________________________________________ ___________________________________________________________________________________________________________________________________________________________________________________________________

• Cyanobacteria is an example of a photosynthetic bacteria.

6 CO2+ 6 H2O -----light------>C6H12O6 + 6 O2

b. ______________________________________________________________________________________________________________________________________________________________________________________________________________. Fermentation is _____________________________________ _______________________________________________. Bacteria will ferment by one of these two equations.

• Pyruvic Acid + NADH ---------->Lactic Acid + NAD+ (also used by animals)

• Pyruvic Acid + NADH ---------->Alcohol + CO2 + NAD+ (also used by

plants)


of 35

Other bacteria are ____________________________________. Facultative anaerobes are ___________________________________________________________________ ___________________________. These bacteria will use cellular respiration if oxygen is present and fermentation if oxygen is not present. Beneficial Bacteria Bacteria provide us with products which we depend every day. For example, bacteria . Some bacteria are used to make pickles and sauerkraut, and some make vinegar from wine. Bacteria are also used in industry. One type of bacteria can digest petroleum, which makes them _______________________________________________________. Some bacteria remove waste products and poisons from water. These bacteria can be ____________________________________________________________. Others can even ___________________________________________________ from the ground. Still others have been __________________________________________________ and chemicals through techniques of genetic engineering. Many kinds of bacteria develop a symbiotic relationship with other organisms in which ______________________________________. Our intestines are inhabited by large numbers of bacteria including E. coli. In the intestines, the _______________________ _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________. Bacteria _______________________________________________________________ _______________________________. Gradually, the material being decomposed is recycled, enriching the soil thereby providing valuable nutrients required for plant growth.


of 35

5.4 PRACTICE: BACTERIAL METABOLISM

1. Please compare and contrast the terms obligate anaerobe and obligate aerobe. (3 marks)

2. Would it technically be incorrect to refer to a facultative anaerobe as a facultative aerobe? Please explain your answer? (2 marks)

3. Tired of always being portrayed as the "bad guys" (see image below), a group of bacteria have hired you as their new public relations (PR) representative. Please design a PR device to improve the image of bacteria in the eyes of the human population. You may design a poster, radio commercial (script), TV commercial (post on YouTube), song (send lyrics or post on YouTube), comic strip, children's colouring pages or any other device that you think will help to inform the public of some of the benefits of bacteria. (10 marks)


of 35

5.5 NOTES: BACTERIAL DISEASE Symbiosis in Bacteria When bacteria live in association with other organisms they are known as ___________________________________________. There are ________________ ____________________________, and different groups of bacteria employ all three.

1. In ___________________________ (+/+) symbiotic relationships, ___________ __________________________________________ from the relationship. For example, nitrogen fixing bacteria live in nodules of legumes. They provide the plant with nitrogen and the plant supplies the bacteria with other nutrients.

2. In a __________________________ (+/0) relationship, ____________________ _______________________________________________________________. Bacteria live on human skin and do not harm us, but benefit from the warm moist environment.

3. A _____________________________ (+/-) relationship means that __________ __________________________________________________________________________________________________. Parasitic bacteria harm the host and ___________________________________________________. Some parasitic bacteria use a human host, so the study of bacteria is of great importance to human beings.

Most bacteria however are not pathogenic. Useful bacteria include:

• decomposers • nitrogen fixing bacteria • vitamin producing bacteria • bacteria used to make insulin (E.coli) and growth hormones • Some bacteria are used to make antibiotics (e.g. Streptomycin)

There are many industrial bacteria. Such as bacteria ___________________________ _____________________________________________________________________. Bacteria __________________________________________________________ ________________________________________________________. Scientists use bacteria in genetic research because they only have 1 chromosome, are easy to grow, and have a short life cycle


of 35

Harmful Bacteria and Koch Postulates As stated previously most bacteria are _____________________ which means they are ________________________________. Many actually help us in some way (digestion, protection). There are relatively few bacteria that are considered to be pathogenic or disease causing. Pathogenic or disease causing bacteria ________________________ ________________________________________________________________________________________________. Bacteria may produce endotoxins and exotoxins which elicit an immune response. Koch’s Postulates ________________________ was a German Bacteriologist who came up with the rules to prove that an organism is responsible for a particular condition or disease. He formulated the "germ theory of disease". He isolated typical rod-shaped bacteria with squarish ends (bacilli) from the blood of sheep that had died of anthrax. Then he Discovered bacteria that caused tuberculosis and cholera. Robert Koch ____________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

1. A specific organism can always be found in association with a given disease.

2. ________________________________________________________________________________________________________________________________

3. The pure culture will produce the disease when inoculated into susceptible

animal.

4. ________________________________________________________________________________________________________________________________________________________________________________________________

http://www.biology-online.org/dictionary/Endotoxin

http://www.biology-online.org/dictionary/Exotoxin

http://www.biology-online.org/dictionary/Exotoxin


of 35

Koch and his colleagues invented many techniques concerning inoculation, isolation, media preparation, maintenance of pure cultures and preparation of specimens for microscopic examination. Examples of Bacterial Disease

1. ______________________________________________: • Strept throat • Rheumatic Fever • Pneumonia • Tuberculosis

2. _____________________________________________:

• Staph • Pimples • Leprosy • flesh eating disease

3. _____________________________________________:

• tetanus • Botulism • meningitis

4. _____________________________________________:

• Typhoid fever • cholera, • Salmonella • E. coli

5. _____________________________________________:

• Gonorrhea • Syphilis

Lines of Defense The human body constantly faces attack from foreign invaders that can cause infection and disease. These invaders range from living microbes such as bacteria, fungi, and viruses, to nonliving toxins, chemicals, and drugs. Fortunately, the body has a number of external and internal safeguards that prevent most dangerous invaders from entering and causing harm. The ______________________________________________ is non–specific and aims to stop microbes from entering the body. The ________________________________ __________________________________________________________ preventing


of 35

penetration by microbes. If the skin is cut then the blood produces a ______________ ___________________________________________________________________________________________. The surfaces of the body – the skin, digestive system, and the lining of the nose – are covered by a _______________________________ ________________________ called the normal body flora. They help to protect a host from becoming infected with more harmful micro-organisms by acting as a physical barrier. It means that the harmful microbes have to compete with the normal body flora for nutrients. The average human gut contains around 1 kg of these good bacteria which is equivalent to one bag of sugar. The respiratory system – the nose and passageways leading to the lungs – is lined with cells that produce sticky fluid called _____________ ____________________________________________________, where they are either coughed or sneezed out or swallowed and then passed out of the body in feces. The body produces several antimicrobial substances that kill or stop microbes from growing. For example the _______________________________________________ ____________________________________. The ____________________________ _____________________________ which destroys many of the microbes that enter the body in food and drink. Urine as it flows through the urinary system flushes microbes out of the bladder and urethra. If microbes do manage to get inside the body then the _________________________ _____________________________ is activated. This is also non-specific as it stops any type of microbe. ___________________________________________________ __________________________________________________________. They send out pseudopodia which allows them to _____________________________________ _________________________________________________. Phagocytes release digestive enzymes which break down the trapped microbes before they can do any harm. This process is called phagocytosis. The __________________________________________________________________ ______________________________________________________________________________________________________________________________________. It is regarded as a threat by the immune system and is capable of stimulating an immune response. Antigens are proteins that are found on the surface of the pathogen. Antigens are unique to that pathogen. The whooping cough bacterium, for example, will have different antigens on its surface from the TB bacterium. When an antigen enters the body, ________________________________________________________________ against it. It is like a battle with the army (antibody) fighting off the invader (antigen). A type of white blood cell called ___________________________________________ ___________________________________________________________________________________________________________________________. Each antibody has a unique binding site shape which locks onto the specific shape of the antigen. The antibodies destroy the antigen (pathogen) which is then engulfed and digested by macrophages. Once the invading microbes have been destroyed the immune response winds down. Once a person has had a disease they don‘t normally catch it again because the body produces __________________________________________________


of 35

_________________________________. The memory cells remember the microbe which caused the disease and ___________________________________________ _________________________________________________________. The pathogen is quickly destroyed preventing symptoms of the disease reoccurring. What are Antibiotics? Antibiotics are _________________________________________________________ _____________________________________________________________. The first antibiotic was discovered by ______________________________________________ in 1928 in a significant breakthrough for medical science. The development of antibiotics is probably the largest advance in medicine in the 20th century, and has saved millions of lives worldwide from infections such as TB. Since ________________________________________________________________ _______________________________, a wide range of antibiotics has been developed. Originally produced from molds and fungi, many antibiotics are now produced synthetically. Antibiotics are not effective against infections caused by viruses, so if you go to your doctor with a viral illness such as a cold, flu or a viral sore throat, antibiotics have no role to play. ____________________________________________________ _________________________________________________. For example, if you have a streptococcal throat, penicillin may be prescribed. __________________________ _______________________________________________________. These are called broad _________________________________________. This type of antibiotic is often used to treat respiratory or urinary tract infections because it is difficult to establish what specific bacteria are causing the condition. Antibiotics can be classified into five main categories:

1. PENICILLINS including: Amoxycillin, Amoxil, Augmentin, Calvepen, Clonamox, Floxapen

2. CEPHALOSPORINS including: Cefodox, Distaclor, Keflex, Suprax, Zinnat 3. AMINOGLYCOSIDES including: Genticin 4. TETRACYCLINES including: Clinimycin, Hostacycline, Minocin, Vibramycin 5. OTHERS including: Ciproxin, Erymax, Erythrocin, Flagyl, Ipral, Klacid, Zithromax


of 35

The choice of antibiotic depends on the _____________________________________ ____________________________________________________________________________________________________________________________________________________________________________________________________________ How do antibiotics work?

An antibiotic is a selective poison. It has been chosen so that it will ________________ ______________________________________________________________________. Each different type of antibiotic affects different bacteria in different ways. Essentially, antibiotic drugs _________________________________________________________ ________________________________________, allowing the body‘s immune system to deal with the infection. For example, an antibiotic might inhibit a bacterium's ability to turn glucose into energy, or its ability to construct its cell wall. The most commonly used antibiotics, penicillins and cephalosporins, are bactericidal and work by ____________________________________________________________. When this happens, the bacterium dies instead of reproducing. Considerations for the use of antibiotics:

• The antibiotic _____________________________________________________. • Some people are ____________________________________________. • Some antibiotics could kill off useful bacteria. ____________________________

________________________________________________________________________________________________________________________________.

• May cause resistant strains to develop. Other biocides include: Sulfur Drugs, antitoxins, various bacteriocides, disinfectants. Chart of various antibiotics:


of 35

Antibiotic Resistance Antibiotics kill or inhibit the growth of susceptible bacteria. Many diseases that once killed people can now be treated effectively with antibiotics. An antibiotic is a _________ _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________. Sometimes one of the bacteria survives because it has the _____________________ _______________________________________________________; that one bacteria can then _______________________________________________________ ______________________________________. Exposure to antibiotics therefore provides selective pressure, which makes the surviving bacteria _________________ ___________________________________________. In addition, bacteria that were at one time susceptible to an antibiotic can ___________________________________ through _________________________________ of their genetic material or by acquiring pieces of DNA that code for the resistance properties from other bacteria. Although bacteria are capable of developing ___________________________________ ______________________________________________________________________a number of factors may speed up the development of resistance. These include:

1. ________________________________________________________________ _______________________________________________________ in humans.

2. Widespread use of antibiotics in the rearing ______________________________

________________________________________________________________

3. _________________________________________________________________ _____________________________ as prescribed by your doctor.

The danger of widespread resistance to antibiotics is that ______________________ __________________________________________________________ (so-called 'superbugs'). There is huge concern among doctors that eventually these 'superbugs' could cause untreatable infections in the otherwise healthy populations. Most infection-causing bacteria can become resistant to at least some antibiotics. Bacteria that are resistant to many antibiotics are known as multi-resistant organisms (MROs). How can it be prevented?

1. __________________________________________________________________________________________ like a cold or the flu.

2. Discard any leftover medication once you have completed your prescribed course


of 35

of treatment.

3. _________________________________________________________________________________________________________________. Complete the prescribed course of treatment even if you are feeling better.

4. Do not take antibiotics prescribed for someone else.

5. Stop the use of antibacterial hand soaps and sanitizers. Wash your hands with regular soap and water instead.

This first bacterial streak plate shows the effect of antibiotic disks on bacteria. There is no growth near the white disks. On this second streak plate the bacteria now exhibit resistance to the antibiotic disks.


of 35

5.5 PRACTICE: BACTERIAL DISEASE

1. The human body has three lines of defense against pathogens (disease-causing agents):

a. Please identify and briefly describe the first line of defenses. (2 marks)

b. Please identify and briefly describe the second line of defenses. (2 marks)

c. Please identify and briefly describe the third line of defenses. (2 marks)


of 35

2. You often hear people express concern that if they use antibiotics inappropriately that "they will become resistant to the antibiotic". While a person is correct in being concerned about the inappropriate use of antibiotics, this particular statement reflects a severe misconception of what "antibiotics resistance" is. What does antibiotics resistance refer to and how does the inappropriate use of antibiotics contribute to its existence? Please include terms such as mutation, selective pressure/natural selection, survival of the fittest and next generation in your answer. (5 marks)

~ END OF BIOLOGY 11 UNIT 5 LEARNING GUIDE ~


of 35

UNIT 5 ANSWER KEY

5.1 PRACTICE: BACTERIAL CLASSIFICATION

1. Recent classification schemes have determined there are three domains of life: a. What are these domains called? (3 marks)

Archaea, Bacteria, Eukaryota

b. Which if these domains contain bacteria? (2 marks) Archaea and Bacteria


of 35

2. What distinguishes the domains that contain bacteria from the one that does not? Hint: think cellular structure. (2 marks)

The domains that contain bacteria (Archaea and Bacteria) includes only prokaryotic cells that lack a nucleus and other membrane-bound organelles. In contrast, the domain that does not contain bacteria (Eukaryota) includes only eukaryotic cells that generally have a nucleus and other membrane-bound organelles.

3. Please classify each of the following bacteria using the terms gram positive, gram negative,

staphylo-, strepto-, diplo-, -cocci, -bacilli, -spirilli. (12 marks)

Shape/Organization Gram Stain Colour

Classification

pink

Example: gram negative, monospirillum

*note: mono = one = individual bacteria

purple

gram positive streptobacilli

purple

gram positive staphylococci

pink

gram negative staphylobacilli

pink

Gram negative streptococci


of 35

4. A gram positive bacteria is likely to have a great deal more _____________________________________________ in its cell wall than a gram negative bacteria and thus, it will bind to and retain the Gram stain better. (1 mark)

5. Chemosynthetic bacteria are said to be ________________________ because they can produce energy and organic compounds for themselves, whereas most other bacteria are ____________________________ as they obtain energy and organic compounds by feeding off of other living things. (2 marks)

5.2 PRACTICE: BACTERIAL STRUCTURE

2. Please draw a simplified diagram of a bacteria cell being sure to include and label the structures listed below. Please include a brief description of the structure's function beside the label. Please be neat. (10 marks)

o nucleoid o plasmid o cytoplasm

o cell wall o fimbriae o ribosomes

o flagella o capsule o plasma

membrane


of 35

5.3 PRACTICE: BACTERIAL REPRODUCTION

1. Please identify which process in being represented by each picture below (transduction, binary fission, conjugation, and transformation) and then provide a brief description of the process in the box beside the picture. (8 marks)

Various Processes that Affect the Genetic Composition of Bacteria

Binary Fission - genetic material replicated then cell divides into two identical (barring mutation) daughter cells

Transduction - viral vector carries genetic material from one bacteria to another during the process of infection

Transformation - bacteria picks up random genetic material from its environment

Conjugation - plasmid (genetic material) is transferred from one bacterial cell to another via a conjugation bridge formed by a pilus/fibriae


of 35

5.4 PRACTICE: BACTERIAL METABOLISM

1. Please compare and contrast the terms obligate anaerobe and obligate aerobe. (3 marks)

Obligate means "required" or "restricted to"…an obligate anaerobe must metabolize and live without oxygen whereas an obligate aerobe must metabolize and live with oxygen.

2. Would it technically be incorrect to refer to a facultative anaerobe as a facultative aerobe?

Please explain your answer? (2 marks)

Facultative means it can occur optionally but is not restricted to a particular condition or environment. A facultative anaerobe can function in the absence or presence of oxygen. Likewise, a facultative aerobe can function in the presence or absence of oxygen. Thus, the terms can be correctly used interchangeably.

3. Tired of always being portrayed as the "bad guys" (see image below), a group of bacteria have hired you as their new public relations (PR) representative. Please design a PR device to improve the image of bacteria in the eyes of the human population. You may design a poster, radio commercial (script), TV commercial (post on YouTube), song (send lyrics or post on YouTube), comic strip, children's colouring pages or any other device that you think will help to inform the public of some of the benefits of bacteria. (10 marks)

Approachesand answers may vary but may include pointing out the benefits of bacteria such as:

o Commensal bacteria preventing colonization of human body by harmful bacteria

o Commensal bacteria helping in digestion and vitamin production o Use in food manufacture such as yogurt, cheese, sour cream, vinegar, and

pickles o Use in bioremediation of oil spills and mining sites o Use in recycling/decomposition of dead matter and nitrogen-fixation. o Use in scientific research. o Use in production of insulin, human growth hormone and Factor VIII for

use in human medicine.


of 35

5.5 PRACTICE: BACTERIAL DISEASE

1. The human body has three lines of defense against pathogens (disease-causing agents):

a. Please identify and briefly describe the first line of defenses. (2 marks)

Non-specific barriers including: o Physical – skin and mucus o Chemical – tears and saliva, stomach acid

b. Please identify and briefly describe the second line of defenses. (2 marks)

Non-specific including:

o Cells – phagocytes

c. Please identify and briefly describe the third line of defenses. (2 marks)

Specific including: o T and B Cells – that work together to destroy specific

pathogens using antibodies produced by B cells

2. You often hear people express concern that if they use antibiotics inappropriately that "they will become resistant to the antibiotic". While a person is correct in being concerned about the inappropriate use of antibiotics, this particular statement reflects a severe misconception of what "antibiotics resistance" is. What does antibiotics resistance refer to and how does the inappropriate use of antibiotics contribute to its existence? Please include terms such as mutation, selective pressure/natural selection, survival of the fittest and next generation in your answer. (5 marks)

Answers should include the following key points:

o Antibiotic resistance refers to a strain of bacteria being resistant (not significantly harmed or controlled by) an antibiotic not to a human being resistant to the antibiotic. Indeed, humans should be resistant to all antibiotics or else their use would kill our cells and therefore, us.

o Bacteria become resistant to an antibiotic through random mutation. This makes them more "fit" in scenarios where an antibiotic is being used.

o When antibiotics are used inappropriately (not taken for the full recommended course) or excessively we are essentially selecting for the naturally occurring resistant mutants.

o We kill off the non-resistant bacteria and all that are left are the stronger


of 35

more resistant bacteria. o These bacteria now have less competition and can rapidly reproduce and take

over the organism they are infecting.

unit 5 ~ learning guide name: - bc learning...

Documents