bios242 exam 1 review notes

A comprehensive set of practice flashcards covering the branches of microbiology, key historical scientists, microscopy, genetics, cellular organization, and acellular infectious agents based on Exam 1 review notes.

What are the six branches of microbiology contained in the acronym "Ma's Pis"?

Medical microbiology, Agricultural microbiology, Public Health microbiology and Epidemiology, Immunology, Industrial microbiology, and Environmental microbiology.

What was the primary contribution of Louis Pasteur's swan neck flask experiment?

He disproved the theory of spontaneous generation by showing that living organisms must be introduced into a sterile broth for growth to occur.

Who was the first person to observe microbes, and who was the first to use a crude microscope to view "animalcules"?

Robert Hook was the first to observe microbes; Anton Van Leeuwenhoek used a crude microscope to examine "animalcules" from teeth scrapings and rainwater.

What are Koch's postulates?

A specific set of steps developed by Robert Koch to link a specific microorganism to a specific disease.

How did John Tyndall contribute to the understanding of microbial heat resistance?

He identified that microbes in dust have a high heat resistance and recognized the existence of endospores, which require more than boiling to destroy.

Which scientist is credited with developing aseptic techniques, including the first use of hand washing and antiseptic mist in operating rooms?

Joseph Lister.

What did Dr. Semmelweis demonstrate regarding childbed fever?

He showed that women in maternity wards became infected after being examined by physicians who came from autopsy rooms without washing their hands.

According to the binomial system of nomenclature established by Carl Von Linne, how is a scientific name written?

The genus is capitalized, the species is lowercase, and the entire name is italicized (if typed) or underlined (if handwritten).

Which light microscope is most widely used in laboratories, and which provides well-defined $3D$ images?

The Bright field microscope is the most widely used; Interference microscopy provides well-defined $3D$ images.

What is the specific application of a transmission electron microscope?

It is specifically used to allow for the visualization of viruses.

In a Gram stain, what is the appearance of Gram-positive versus Gram-negative cells?

Gram-positive cells stain purple, while Gram-negative cells stain red or orange.

What are the two bacterial genera characterized by the ability to form endospores?

Bacillus and Clostridium.

What is meant by "semi-conservative" DNA replication?

Each daughter molecule is identical to the parent in composition, consisting of one original template strand and one newly synthesized DNA strand.

Match the DNA replication enzymes to their functions: Helicase, Primase, and DNA Ligase.

Helicase unwinds the double-stranded DNA helix; Primase provides an RNA primer; DNA Ligase fills in gaps.

Define the three main types of horizontal gene transfer: Conjugation, Transformation, and Transduction.

Conjugation is the direct transfer of a plasmid through a pilus; Transformation is the uptake of free DNA from the environment; Transduction is genetic transfer mediated by a bacteriophage.

What are "jumping genes," and who proposed them in 1951?

Transposons; they were proposed by Barbara McClintock.

How does ultraviolet (UV) light act as a mutagen?

It causes cross-links between adjacent pyrimidines, specifically forming thymine dimers in the DNA.

Distinguish between a Missense mutation and a Nonsense mutation.

A Missense mutation leads to the placement of a different amino acid; a Nonsense mutation changes a normal codon into a stop codon.

What effect does a Frameshift mutation typically have on a protein?

It nearly always results in a non-functional protein because it changes the reading frame for every amino acid following the mutation.

Which bacterial structures are used for attachment to surfaces and transfer of genetic material?

Fimbriae are used for attachment to surfaces; the pilus (pili) is used for the transfer of plasmids.

Compare the cell wall structures of Gram-positive and Gram-negative bacteria.

Gram-positive cells have a thick peptidoglycan layer with lipoteichoic acids; Gram-negative cells have a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides ($LPS$).

What are the ribosome sizes for Bacteria, Archaea, and Eukarya?

Bacteria have $70S$ ribosomes; Archaea have $70S$ ribosomes (structured more like $80S$); Eukarya have $80S$ ribosomes.

What is a "provirus"?

A virus that has incorporated its genetic material into the host's DNA rather than remaining in the cytoplasm.

During which phase of mitosis do chromosomes pull apart to opposite sides of the cell?

Anaphase.

Distinguish between the fungal spores: sporangiospores and conidiospores (conidia).

Sporangiospores form within a sac-like structure called a sporangium; conidiospores are free spores that pinch off from the fungus.

What are the six general phases of the animal virus multiplication cycle?

1. Adsorption (attachment), 2. Penetration, 3. Uncoating, 4. Synthesis, 5. Assembly, and 6. Release.

Define Class VI in the Baltimore system of virus classification.

Single-stranded RNA viruses that use reverse transcriptase, such as HIV.

What are the primary differences between prions and viroids?

Prions are infectious proteins that affect animals; viroids are infectious strands of naked RNA that infect plants.