Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

1

Monera

Definitions:

Unicellular: a single celled organism/ organism composed of only 1 cell

Prokaryote: a living organism that does not have a nucleus or membrane enclosed cell

organelles

Autotroph: a living organism that has the ability to make its own food

Chemosynthetic: a living organism that makes its own food using chemical

Photosynthetic: a living organism that makes its own food using chemical

Heterotroph: a living organism that does not have the ability to make its own food

Parasite: a living organism that lives and feeds on a living host and causes harm to host

Saprophyte: a living host that feeds on dead organic matter and returns essential nutrients to

the soil.

Symbiotic bacteria: two organisms of different species living together involving benefit

Obligate aerobe: can only grow in the presence of oxygen

Obligate anaerobe: can only grow in the absence of oxygen

Facultative anaerobe: can grow in the presence or absence of oxygen

Endospore: a hard protective shell that allows bacteria to survive until conditions become

favourable again

Bioprocessing: an industry that uses microorganisms to make products

Bioreactor: a vessel/container that biochemical reactions occur in

Antibiotic: proteins produced by microorganisms to kill other microorganisms.

Antibiotic resistance: microorganisms do not die in the presence of an antibiotic due to misuse

Asepsis: free from all harmful microorganisms

Sterile: free from all microorganisms

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

2

Aseuxal reproduction: reproduction involving one parent

Binary fission: asexual reproduction of bacteria by mitosis

Antigen: foreign body

Pathogen: disease causing antigen

Species: interbreeding between organisms to produce fertile offspring

Ectoparasite: parasite that lives on the surface of the living host; causing harm to the host

Endoparasite: parasite that lives inside of the living host; causing harm to the host

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

3

Members of the kingdom Monera

Prokaryotes (no nucleus or no membrane around cell organelles)

Can be divided into two categories

o Autotrophs: make their own food

Photosynthetic: bacteria that make their own food using light

Chemosynthetic: bacteria that make their own food using chemicals e.g.

rhizobium bacteria make their own food using Nitrogen (important in the

nitrogen cycle)

o Heterotrophs: cannot make their own food

Parasites: feed and reproduce inside a living host of a different species causing

harm to the host. Symbiotic Bacteria are bacteria that live in the presence of a

different species (eg. small intestine of humans) and both benefit from the

relationship. These bacteria produce vitamin K which is required by humans to

clot blood in conjunction with platelets. These bacteria also create competition

with harmful microorganisms. Bacteria that cause disease are known as

pathogens

Saprophytes: feed on dead organic matter and return essential nutrients to the

soil

Shapes of Bacteria:

Round/ cocci eg; Streptocci

Rod eg; Bacillus Anthrax

Spiral eg; Vibrio Cholerae

Structure of a typical bacterial cell

www.shmoop.com

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

4

Unicellular: single celled organisms that reproduces by binary fission (aka mitosis/ asexual

reproduction)

o DNA replicates

o Cells elongate and grow

o Membrane forms around replicated information and cell divide

o Results in two identical daughter cells produced

o Happens every 20 mins

o Rapid reproduction rate results in mutations and can lead to resistance to antibiotics

Growth of Bacteria

o Factors affecting growth of bacteria

o Bacterial growth curve

Factors which affect the growth of bacteria:

1. Temperature

2. O2 concentration: the growth of bacteria affected by the amount of O2 present.

Aerobic Bacteria: require oxygen in order to grow

Anaerobic bacteria: will only grow in the absence of oxygen

Facultative Anaerobes: will grow in the presence or absence of oxygen

3. pH: pH required by bacteria to grow varies depending upon their desired growth location eg.

Bacteria in the stomach will have an optimum pH of 2 while bacteria in the small intestine will

have an optimum pH of 8

4. solute concentration: higher external solute (salt) concentration in the surrounding environment

to the bacteria will lead to water leaving the bacteria ie dehydration and enzymes stop working

(basis of food preservation)

5. pressure: bacteria will only grow under low pressure

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

5

Bacterial Growth Curve: (5 stages-be able to draw graph and identify the stages on a graph)

Lag phase: bacteria are adjusting to their new environment. Very little increase in bacterial numbers

Log phase: due to the abundance of food and space, bacteria begin to reproduce rapidly

Stationary phase: number of bacteria reproducing is equivalent to the number of bacteria dying as food

and space becomes limited in addition to the build up of waste products

Decline phase: number of bacteria dying is greater that the number of bacteria being reproduced

Death/Survival phase: death of bacteria only occurring or those that survive form an endospore

If conditions are not favourable for bacteria to grow, they will not die but instead for a protective layer

around them known as an endospore. This is a hard shell that will protect the bacteria until conditions

become favourable again

Endospore formation

content of cell dehydrates

plasmid replicates

with the assistance of enzymes, endospore forms

Economic importance of Bacteria (know two of each)

Beneficial Harmful

Drug production (antibiotics) Food spoilage

Biodegradation of waste Illness and disease

Regulate environment of the small intestine

Produce vitamin K to help clot blood

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

6

The use of bacteria in industry

Bioreactor: all reactions in industry involving bacteria take place in a bioreactor. A bioreactor is a vessel

in which biochemical reactions occur. (Must include the underlined words to get full marks when asked

in an exam “what is a bioreactor?”)

Use of bacteria in batch and continuous processing

Bioprocessing: the use of micro organisms to make products in industry

Batch Continuous

fixed amount of reagents

added to bioreactor for fixed amount of

time

fixed amount of product collected

system closed down to be cleaned and

another product made

goes through all stages of bacterial

growth curve

reagents fed into bioreactor ongoing

basis

product collected as made

system rarely shut down

remains in stationary stage

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

7

Batch Continuous

Advantages Can make a number of different products

Can produce large quantities of a single product. Leads to low

energy consumption

Disadvantages System has to be shut down and cleaned in between

products. This is time consuming and expensive

Limited to one product only

Asepsis: an environment in which all harmful micro organisms are removed

Sterile: environment that is free from all micro-organisms

Antibiotics and antibiotic resistance

Antibiotics are proteins produced by micro organism to kill bacteria and fungi

Antibiotics will not work on viral infections so it is of not benefit giving antibiotics to treat a cold or flu

(which are viruses). It will only lead to antibiotic resistance

Antibiotic resistance: micro organisms (bacteria and fungi) do not die in the presence of antibiotic.

Caused by misuse or overuse of antibiotics

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

8

Revision Questions on Bacteria

1. Name the kingdom to which bacteria belong

2. Explain the term prokaryotic organisms

3. Give an example of an organism that is a eukaryote.

4. Explain the term eukaryote

5. Bacteria are considered to be unicellular. State how they reproduce

6. How often do bacteria reproduce

7. State a major cause for concern associated with the rate at which bacteria reproduce and

identify the effect this concern may have

8. Bacteria are divided based on their feeding mechanism. State the two categories bacteria can be

divided into and explain why a bacteria may be place in each of the categories listed

9. Explain how bacteria feed if they are classified as being a parasite

10. Give an example of an chemosynthetic bacteria

11. Identify stage 3 of the bacterial growth curve

12. State and explain the stage that follows stage 3

13. Explain what happens during the log stage of the bacterial growth curve

14. Provide a reason why bacteria may begin to die during the stationary stage of the bacterial

growth curve

15. What is the optimum pH at which bacteria grow

16. State two factors necessary for bacteria to grow

17. If conditions become unfavourable bacteria adapt in order to survive. State what this adaptation

is

18. What is a bioreactor

19. State an advantage and a disadvantage of batch processing

20. State one advantage and one disadvantage of continuous processing

21. State two beneficial economic importance of bacteria

22. State two harmful economic importance of bacteria

23. Some bacteria are considered to be facultative anaerobes. Explain the underlined term

24. Draw a graph of the bacterial growth curve labelling the x and y axis accurately

25. Outline the events involved in asexual reproduction of bacteria

26. State the role of salt/sugar in the destruction of bacteria in food preservation to prevent food

spoilage

27. What are pathogens

28. State the factors necessary in order for bacteria to grow

29. State the difference between “asepsis” and “sterile” by writing a note on each

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

9

Bacteria Exam Paper Questions

Homework- 2015 15 (c)

2013 12 (b)

(i) Name the kingdom to which bacteria belong._____________________________

(ii) Draw a large diagram of a bacterial cell to show:

1. The relative positions of the cell wall, cell membrane and capsule.

2. A plasmid.

Label each of the above structures.

(iii) 1. Under what circumstances does a bacterial cell form an endospore?

__________________________________________________________________________________

2. Describe briefly how an endospore forms.

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

10

__________________________________________________________________________________

(iv) Name two types of heterotrophic nutrition used by bacteria.

_________________________________________________________________________________

2010 15 (c)(ii)

(ii) Doctors are reluctant to prescribe antibiotics to patients suffering from common cold-like

symptoms.(3 valid pieces of information) ________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

_________________________________________________________________________

2008 15 (c)

The diagram shows a bacterial growth curve.

(i) A and B represent the labels on the axes. What does each of them stand for?

A____________________________________

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

11

B____________________________________

(ii) What term is applied to the part of the curve labelled x? What is happening during x?

X___________________________________________________________________

Happening At X _______________________________________________________

(iii) What term is applied to the part of the curve labelled y? What is happening during y?

Y__________________________________________________________________

Happening at Y ______________________________________________________

(iv) Copy the diagram into your answer book and continue the curve to show the next phase.

Explain why you have continued the curve in this way. _____________________________________

_____________________________________________________________________________________

_______________________________________________________________________________

(v) Distinguish between batch and continuous flow food processing using micro-organisms in

the food industry.

Batch

_____________________________________________________________________________________

_______________________________________________________________________________

Continuous ________________________________________________________________________

_____________________________________________________________________________________

_______________________________________________________________________________

2006 15 (b)

Distinguish between photosynthetic and chemosynthetic bacteria. Give an example of each type.

Photosynthetic _____________________________________________________________________

__________________________________________________________________________________

Example __________________________________________________________________________

Chemosynthetic ____________________________________________________________________

__________________________________________________________________________________

Example __________________________________________________________________________

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

12

(ii) Name two forms of heterotrophic nutrition found in bacteria. 1. __________________________

2. ________________________________________________________________________________

(iii) What are antibiotics? For what purpose are they used? __________________________________

_____________________________________________________________________________________

_____________________________________________________________________________________

____________________________________________________________________________

(v) Explain what is meant by antibiotic resistance and suggest how it may develop ________

___________________________________________________________________________

___________________________________________________________________________

__________________________________________________________________

2005 15 (b)

(i) Draw and label a diagram to show the basic structure of a typical bacterial cell.

(ii) Other than being prokaryotic, state two ways in which a typical bacterial cell differs from a

typical human cell (e.g. cell from cheek lining).

1. ______________________________________________________________________________

________________________________________________________________________

2. ______________________________________________________________________________

________________________________________________________________________

(iii) Describe how some bacteria respond in order to survive when environmental conditions

become unfavourable.

_____________________________________________________________________________________

_______________________________________________________________________________

(iv) What is meant when a bacterium is described as being pathogenic? _______________________

__________________________________________________________________________________

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

13

(v) What are antibiotics? Use your knowledge of the Theory of Natural Selection to explain the

possible danger involved in the misuse of antibiotics

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

__________________________________________________________________________

Homework-DEB 2010

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

14

Examcraft 2010

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

15

Examcraft 2016

Subject: Leaving Certificate Biology Higher Level

Teacher: Ms. R. Doyle

Week: Week 8

Title: Monera

16