Scientific Method + Microorganisms Lecture Notes

Flashcards covering the scientific method, microorganisms, viruses, fungi, bacteria, protists, diseases caused by microorganisms, immunity, and biotechnology.

What does validity refer to in the context of the scientific method?

Environmental method/scientific process. Test only one variable at a time, identify controlled variables, choose an appropriate design.

What does reliability refer to in the context of the scientific method?

Results are obtained consistently. Repeat the experiment, increase the sample size, take many readings, select a random sample.

What does accuracy refer to in the context of the scientific method?

Care taken by the investigator in making measurements, use appropriate apparatus, ensure apparatus is correctly calibrated.

A table shows the relationship between independent variable and dependent variable over a period of time. How are IV and DV organized in the table?

IV is on the top/left side/first column; DV is on the bottom/right side/second column. Shows the relationship between independent and dependent variables over time.

How do you represent quantitative data on a line graph?

Join dots with a straight line using a ruler. Shows quantitative (numerical) data like time, distance, mass.

How are bar graphs used to show discontinuous qualitative data?

Equal spaces between each bar because data on x-axis is discontinuous; bars must be the same width. Shows discontinuous qualitative (non-numerical categories) data like types of…

What are the characteristics of a histogram?

Bars are the same width and touch each with no spaces. Shows groups of quantitative (numerical) data on a continuous scale.

How to calculate total magnification?

Total magnification = (magnification of eye piece lens) x (magnification of objective lens).

How to calculate Magnification?

Image size / actual size, ensure both sizes are in the same unit.

How to calculate Actual Size?

Image size / magnification, ensure both sizes are in the same unit.

What is Continuous Data?

Can be represented by any value in an interval, e.g. temperature or height.

What is Discontinuous Data?

Can only be represented by separate values in distinct categories or groups, e.g. different chemicals in fertilizer.

What are microorganisms?

Living organisms that are so small they cannot be seen with the naked eye; most abundant organisms on earth.

What are the favorable conditions for the growth and multiplication of microorganisms?

Sufficient food, moisture, optimum temperature (5 to 60 degrees), neutral pH levels.

Are microorganisms harmful?

Some cause disease and are known as pathogens; most pathogens are parasites and live in or on other organisms.

What are some basic characteristics of viruses?

Can only reproduce inside cells of living organism; acellular; infect plant, animal or bacteria cells.

What is a bacteriophage?

Virus that infects bacteria cells. Used to control bacteria population.

What are some diseases caused by viruses?

Tobacco mosaic virus (TMV) in plants; AIDS, colds, flu, rabies, measles, and polio in humans.

What are the cause, effects, and management strategies for rabies?

Cause: rabies virus; effects: attacks the nervous system; management: vaccinate pets, post-exposure treatment (vaccine and immunoglobulin).

What are the cause, effects, and management strategies for HIV/AIDS?

Cause: HIV virus; effects: attacks the immune system; management: antiretroviral therapy (ART).

What are the cause, effects, and management strategies for influenza?

Cause: influenza viruses; effects: respiratory illness; management: annual vaccines, antivirals, hygiene.

What is the difference between macroscopic fungi and microscopic fungi?

Macroscopic fungi are fleshy fungi like mushrooms while microscopic fungi are unicellular yeasts or bread mold-like multicellular molds.

Describe the basic structure of Fungi

Kingdom Fungi, multicellular and consists of a mass of branched filaments or hyphae. the vegetative body, known as the mycelium. Rhizopus is a thallus because no true roots, stems and leaves can be distinguished

What is the role of fungi in maintaining balance in the environment?

Main decomposers in forests and soil; break down dead plants, animals, and organic waste into simpler substances.

What are the cause, effects, and management strategies for rust in plants?

Fungi (Puccinia) causes leaf spots and reduced crop yield; treatment: fungicides, resistant crops, sanitation.

What are the cause, effects, and management strategies for ringworm?

Dermatophyte fungi causes red itchy rings on skin; treatment: antifungal cream, hygiene.

What are the cause, effects, and management strategies for athlete’s foot?

Trichophyton fungus causes itchy, peeling skin on feet; treatment: keep feet dry, antifungal treatment.

What are some symbiotic relationships involving fungi?

Mutualistic relationships between fungi and algae/cyanobacteria (lichens) or fungi and plant roots (mycorrhizae).

Where can bacteria be found?

Classified under the kingdom Monera. Occur in almost any imaginable habitat on earth. Some are aerobic, while others are anaerobic. Some are pathogenic.

Describe the basic structure of bacteria.

Unicellular and occur as single cells, filaments, or colonies. Bacterium cell is surrounded by a cell wall consist of polysaccharides, proteins and lipids. plasma membrane (cell membrane), which encloses the cytoplasm , occurs directly below the cell wall

What are the various bacteria shapes?

Rod shaped (bacillus), spherical/round (coccus), comma shaped (vibrio), spiral shaped (spirillum).

What is the role of Bacteria in Maintaining Environmental Balance?

Decomposer bacteria break down dead plants and animals; bacteria in the nitrogen cycle convert nitrogen into usable forms for plants; bacteria in guts aid digestion.

What are the different diseases caused by bacteria?

Blight: fungi, bacteria, or viruses cause plant decay; treatment: resistant varieties, fungicides, crop rotation. Cholera: Vibrio cholerae causes diarrhea; treatment: rehydration, clean water, antibiotics.

What are the different diseases caused by bacteria?

TB: Mycobacterium tuberculosis causes lung damage; treatment: long-term antibiotics, BCG vaccine. Anthrax: Bacillus anthracis causes skin infection; treatment: early antibiotics, vaccination.

Describe parasitic relationship?

Bacteria benefit by feeding on host; host is harmed (gets sick).

What are Protozoa?

Animal-like, unicellular, heterotrophic organisms (e.g., Amoeba, Paramecium, Plasmodium). No cell wall.

What are Algae?

Plant-like, uni or multicellular, autotrophic organisms (e.g., red, brown and green algae; diatoms, Euglena, dinoflagellates). Chloroplasts; Cell wall (cellulose in green algae)

What are Slime and Water Molds?

Fungus-like, multicellular, heterotrophic organisms (e.g., slime molds). Have cell walls (often cellulose); Multinucleate in some species. Move and feed by phagocytosis

What are general characteristics Protists.

Algae are autotrophic; protozoa ingest food by phagocytosis; cell wall composition varies.

What is the role of protists in maintaining balance in the environment?

Algae (like phytoplankton) produce up to 50% of Earth’s oxygen; some protists (like slime molds) break down dead organisms.

Provide an example of protists' role in the environment.

Example: Diatoms, green algae; recycle nutrients. Feed small animals like zooplankton, which feed fish and larger animals

What are the disease caused by protozoa?

Malaria: Plasmodium (protozoan) transmitted by mosquito bite; symptoms: fever, chills. Prevention: insect repellents and mosquito nets

What are the disease caused by protozoa?

Amoebic Dysentery: Entamoeba histolytica transmitted by contaminated food/water; Symptoms: diarrhea, stomach cramps. Prevention: Drink clean, treated water. Cook meat thoroughly. Practice good hygiene and sanitation

What are the disease caused by protozoa?

African Sleeping Sickness: Trypanosoma brucei transmitted by Tsetse fly bite. Symptoms: Fever, headaches, confusion, coma. Giardiasis: Giardia lamblia transmitted by Contaminated water. symptoms: Diarrhea, bloating, cramps

What is the role of microorganisms in maintaining balance in the environment as produces in food chain and decomposers?

Both algae (like phytoplankton) and autotrophic bacteria produce organic nutrients by photosynthesis; decomposition bacteria, saprophytic fungi and protists (e.g. slime moulds) break down dead organic matter.

What is the role of microorganisms in maintaining balance in the environment as the are important for Nitrogen cycle and maintaining balance between O2 and CO2?

Free-living soil bacteria and nodule bacteria convert free nitrogen into nitrates and make it accessible to plants; Autotrophic bacteria and protists (algae) use carbon dioxide (CO2) and release oxygen (02) during photosynthesis.

What type of disease is AIDS?

AIDS (Acquired Immune Deficiency Syndrome) is a sexually transmitted disease caused by a virus known as Human Immunodeficiency Virus (HIV).

What type of human immune system cells does HIV infect?

The virus infects cells of the human immune system known as CD-cells

What percentage of the population is affected by AIDS in South Africa?

There are approximately 3,4 million AIDS orphans in South Africa because AIDS affects people in their most productive years (20 - 40 years)

What direct and indirect HIV/AIDS are associated with?

Medical care and medication plus time lost due to illness, recruitment, training costs, care for AIDS orphans.

What are some of the HIV/AIDS preventative measure can reduce the chance of/or prevent HIV infection

Treat other sexually transmitted diseases; avoid direct contact with blood; wear rubber gloves; do not share needles; avoid alcohol and drug abuse; practice protected, safe sex

What is drug-resistant tuberculosis?

Drug-resistant TB bacteria do not respond to medication and this resistance is largely due to badly managed TB care and the incorrect use of anti-TB drugs.

What management methods can be put into place to minimize the spread of TB

Every baby must be vaccinated with the BCG vaccine against TB shortly after birth to provide immunity during childhood, counselling of patients and their families is very important

What the symptoms of Malaria?

Symptoms are Fever, headache, shivering, joint pain, vomiting convulsions.

WHat treatment measures are implemented for Malaria?

Treatment measures are Immediate and effective treatment with a combination of anti-malarial drugs is essential.

What measures were in place 1996 to minimize Malaria in South Africa?

In South Africa the incidence of malaria is controlled due to the cautious use of DDT. In 1996 because great pressure was placed on South Africa to stop the use of DDT for indoor spraying.

WHat is a fungal infections caused by Candida?

Candidiasis, or thrush, is a fungal infection caused by various Candida species, with Candida albicans being the most common. The infection is also known as a yeast infection because Candida albicans is a type of yeast fungus.

How does an organism protect itself from pathogenic viruses, bacteria, protozoa or fungi?

The body monitors the constant exposure to harmful elements (internal or external), is known as the immune response.

How are white blood cells able to recognize pathogens as foreign cells

Protein molecules, known as antigens, occur as markers on the surface of all body cells, viruses, bacteria, protozoa and fungi. The white blood cells (leucocytes) recognise the pathogens as foreign cells as

How do B-lymphocytes recognize pathogens?

B-lymphocytes have receptor proteins on their surface which attach to specific antigens on the surface of a pathogen. The receptor proteins recognise the pathogens as foreign.

How do certain chemical composition antibiotics kill bacteria

By weakening the cell wall of the bacterium and causing the cell to burst. by damaging the cell membrane of the bacterium and causing the cell contents to leak out, resulting in death of the cell.

What occurs when antibiotics administer to a patient under the wrong circumstances

Antibiotics only kill bacteria and not viruses. Antibiotics may incorrectly the treatment to a patient in a viral infection such as a cold

How is human insulin produced through genetic engineered using recombinant DNA technology?

A segment of DNA (a gene) is extracted from one organism and inserted into the DNA of another organism. The newly formed DNA is known as recombinant DNA.

What occurs when Antibiotics are used?

Antibiotics lead to Antibiotic resistance – bacteria evolve and become hard to kill as it harms good and bad bacteria

Why and describe what Micro-organisms are used for?

Micro-organisms are used to make parts of viruses or bacteria for vaccines.Yeast are used to make Hepatitis B vaccine and some growth hormones

What process is applied to create Wine produce from microorganism?

Wine consist of Fermentation of sugars in grapes using Yeast. Alcoholic drinks produced from Yeast such as Beer and Wine