Lab Techniques
In gel electrophoresis, what electrical charge does a DNA molecule have?
What is a negative charge?
These are the two basic structural components found in nearly all viruses.
What are a protein coat and nucleic acid (genetic material)?
In the DNA molecule, this base always pairs with Adenine (A), and this base always pairs with Guanine (G).
What are Thymine (T) and Cytosine (C)?
This is the study of the incidence, transmission, and control of diseases.
What is epidemiology?
This Hungarian physician was the first to advocate for hand washing in a medical setting in the mid-1800s.
Who is Ignaz Semmelweis?
This is the term for a clearing free of bacterial growth around a paper disk soaked with a chemical.
What is a zone of inhibition?
This is why viruses are considered non-living microbes.
What is their reliance on living, cellular organisms for self-replication?
This is the total number of chromosomes in a normal human somatic (non-germline) cell.
What is 46 (or 23 pairs)?
This is the difference between direct and indirect contact transmission
What is that direct contact is human-to-human physical contact, while indirect contact occurs via a contaminated object?
His germ theory of disease, published in 1880, showed that microorganisms are responsible for many diseases.
Who is Louis Pasteur?
When separating DNA fragments using electrophoresis, this is why smaller pieces of DNA move faster through the gel than larger pieces.
Smaller pieces can snake through the gel relatively quickly, while large pieces face more impediments?
This type of mutually beneficial relationship is one where humans house and feed microbes, which in turn help keep us healthy.
What is symbiosis?
This is a grouping of an individual's chromosomes arranged by size, centromere position, and banding pattern.
What is a karyotype?
An imbalance in the type and number of microbiota that may lead to poor health.
What is dysbiosis?
The difference between an antiseptic and a disinfectant.
What is that antiseptics are used on animate (living) surfaces while disinfectants are used on inanimate surfaces?
These are the three steps for creating a bacterial lawn after the first streak down the center of the plate.
What are: Streak back and forth across the entire plate from top to bottom, turn the plate about 60 and repeat the streaking, turn the plate another 60 and repeat a third time.
Name the oral protozoan mentioned in the lab and the structures it uses to move.
What is Entamoeba gingivalis, which moves using pseudopods?
This is the difference between a monosomy and a trisomy.
What is that a monosomy means one chromosome of a pair is missing, while a trisomy means there is an additional chromosome (3 copies total)?
This is how high numbers of acid-producing bacteria lead to tooth decay.
What is by clinging to teeth in plaque and producing acids that break down the tooth's enamel, allowing bacteria into the live tissues?
The most effective level of microbial control, which kills or removes all microbes, including endospores.
What is sterilization?
The negative control in your antimicrobial experiment showed a zone of inhibition and the positive control did not, these two potential errors in the experimental setup could have caused that result.
What are: 1) The water used for the negative control could have been contaminated or the forceps/disk were not properly decontaminated, causing unexpected inhibition. 2) The Staphylococcus epidermidis strain used could be resistant to ciprofloxacin, or the ciprofloxacin disk itself was defective.
This is how commensal microbes help fight off pathogenic organisms.
What is by creating a physical barrier on surfaces and by producing a chemical arsenal of compounds to fight off intruders?
These are the differences between chromosomal abnormality caused by an insertion versus one caused by a translocation, and explain how a cytogeneticist might visually distinguish them on a karyotype.
What is an insertion is when an extra segment is added within one chromosome arm, making that single chromosome longer. A translocation is when two different chromosomes swap segments, which would result in changes to the length and banding patterns of two separate chromosomes in the karyotype.
Besides direct and indirect contact, name three other modes of disease transmission.
What are inhalation of contaminated droplets , contaminated food or water, and insect vectors?
How Louis Pasteur's germ theory of disease provides the foundational scientific principle for the antimicrobial activity experiment you performed.
What is that Pasteur's theory established that microorganisms cause disease and are present in the environment. This principle is the basis for the experiment, which assumes that bacteria will grow on the agar unless a chemical agent actively kills or inhibits it demonstrating a method of controlling the germs Pasteur described.