Biology 11: Bacteria
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Matching: Match the terms on the left with the definitions on the right
Term
Definition
g
Endospore
a. A small extension of bacterial membrane and used in conjugation
g
Conjugation
b. Spiral shaped bacteria
a
Pilus
c. Rod shaped bacteria
d
Cocci
d. Sphere shaped bacteria
c
Bacilli
e. Process used to convert food to energy in absence of oxygen
b
Spirilla
f. Thick walled enclosure of cytoplasm and DNA used to withstand extreme
environments
e
Fermentation
g. Process in which bacterial plasmids are exchanged
Error search: Read the statements below. If the statement is incorrect, modify the underlined portions to make the
statement correct. Write the corrections in the space below each statement. If the statement is correct be proud that
you know your stuff.
CELL SHAPE
1. Bacteria that are rod shaped are called baccilus, spherical are cocci and spiral are spirila.
CELL WALL
2. Gram staining allows us to determine the composition of bacterial cell walls.
3. The techniques was developed by Hans Christian Gram.
4. The stain contains two dies, crystal violet and safranine.
5. Gram Negative bacteria take up the red dye (safranine) and have an extra layer of lipids and proteins
6. Gram Positive bacteria take up the purple dye (crystal violet) and have thick walls made up of proteins and
carbohydrates.
MOVEMENT
7. While some bacteria are sessile, others may move by lashing motions or long whip like fiagella.
OBTAIN ENERGY
8. There are two types of autotrophic bacteria: Chemotrophic and Phototrophic
9. Chemotrophic heterotrophs injest organic molecules as a means of obtaining energy.
RESPIRATION
10. Fermentation enables cells to produce energy in the absence of oxygen
11. Obligate aerobes: require constant supply of oxygen
12. Obligate anaerobes: must live in the absence of oxygen
BACTERIAL REPRODUCTION
13. Binary Fission is when bacterium doubles in size and replicates DNA and divides in half
14. Conjugation is when an exchange genetic information, long protein bridge from donor to recipient
15. Spore formation occurs when growth conditions become unfavourable
Concept Questions:
1. Describe the three basic shapes of bacteria
cocci - round
bacilli – rod shape
spirila – spiral shape
2. Each of the tubes below contains a specific type of bacteria. The three possible types are: Closteridium
botulinum an obligate anaerobe, Escherichia coli a facultative anaerobe and Streptococcus pneumonia an
obligate aerobe.
1.
2.
3.
4.
Tube 1 contains Streptococcus pneumonia bacteria.
Tube 2 contains Closteridium botulinum bacteria.
Tube 3 contains Escherichia coli bacteria.
In a short paragraph explain how you were able to identify which type
of bacteria was in each tube.
-tube1 – obligate aerobe because only at top near air
-tube2- obligate anaerobe because only grows at bottom
-tube3- throughout
5. Describe binary fission.
-bacterium increases in size
-double chromosome
-divides into two
6. What is conjugation in bacteria? Why is it important?
-conjugation is when a protein bridge forms between tow bacteria in which plasmids ( small nonchromosal pieces of DNA)
7. Give specific examples showing the importance of microbial sterility in
a) your kitchen
b) a microbiology lab
8. The antibiotic penicillin is a natural secretion of a certain kind of fungus called Penicillium. Penicillin
kills bacteria. Why might a fungus have evolved a way to kill bacteria?
-The fungus competes with the bacteria for nutrients and have similar lifestyles. By producing a toxin it
can kill off competing bacteria