Chapter 1: The Cell 1.1 and 1.2 Flashcards
Hyperbaric oxygen may be used as a treatment for certain types of bacterial infections. In this therapy, the patient is placed in a chamber in which the partial pressure of oxygen is significantly increased, increasing the partial pressure of oxygen in the patient’s tissues. The treatment is most likely used for infections with:
Obligate anaerobic bacteria
Which of the following does NOT describe connective tissue cells
Connective tissue cells do NOT count for most cells in muscles, bones, and tendons.
(A)
Side Note: stroma is the tissue and cells that support and structure organs, glands, and other tissues. It’s made up of connective tissue, blood vessels, nerves, and lymphatic vessels. Stroma provides nutrients to tissue and organs, removes waste and extra fluid, and may be involved in the body’s immune response.
Which of the following types of nucleic acid could form the genome of a virus?
The types of nucleic acid that could form the genome of a virus are all three shown in the picture. Viruses may have single-stranded RNA, double-stranded DNA, and single-stranded DNA.
The theory of spontaneous generation states that living organisms can arise from nonliving material. In 1859, Pasteur demonstrated that no organisms emerged from sterilized growth media, weakening the theory of spontaneous generation and supporting which tenant of cell theory?
C. Cells arrive only from pre-existing cells.
Mitochondrial DNA is:
Mitochondrial DNA is circular and self replicating. Mitochondrial DNA is NOT single-stranded.
Which of the following is NOT a function of the smooth endoplasmic reticulum?
The smooth endoplasmic reticulum is not responsible for protein synthesis.
The smooth endoplasmic reticulum is responsible for lipid synthesis, poison detoxification, and transport of proteins.
Sidenote: the rough endoplasmic reticulum is responsible for protein synthesis.
What is the main function of the nucleolus?
The main function of the nucleolus is ribosomal RNA synthesis.
Which of the following organelles is surrounded by a single membrane?
A lysosome is a single membrane organelle found in animal cells that breakdown and recycle waste. Lysosomes are known as the “garbage disposal“ of an animal cell.
Which of the following is not a difference that would allow one to distinguish a prokaryotic and a eukaryotic cell?
C
Both prokaryotic and eukaryotic cells have the presence of a membrane on the outside surface of the cell.
Ribosomal sub unit weight (eukaryotic ribosomes contain additional ribosomal RNA molecules and proteins compared to prokaryotic ribosomes, leading to a larger overall size and higher molecular weight), presence of a nucleus, and presence of membrane bound organelles are all differences that would allow one to distinguish a prokaryotic and a eukaryotic cell.
Which of the following does not contain tubulin?
Cilia, flagella, and centrioles all contain tubulin.
Microfilaments are thin, flexible protein fibers that are part of a cell’s cytoskeleton, primarily composed of the protein ACTIN, and play crucial roles in cell movement, shape changes, and cytokinesis (cell division) by providing structural support and facilitating cellular contractions through interactions with myosin proteins; they are considered the smallest filaments within the cytoskeleton
Herpes simplex virus (HSV) enters the human body and remains dormant in the nervous system until it produces an outbreak after exposure to heat, radiation, or other stimuli. Which of the following statements correctly describes HSV?
C
The lytic cycle is a virus cycle in which it replicates its proteins into the viral structure and lyses, or ruptures, out of the hosts cell. The lysogenic cycle is a virus cycle in which it replicates its genetic code inside the host cell. Option D is unrelated to the information given in the question.
Resistance to antibiotics is a well recognized medical problem. Which mechanism can account for a bacterium ability to increase its genetic variability and thus adapt itself to resist different antibiotics?
C
Binary fission refers to the mechanism by which bacterium replicate and is therefore not part of the answer.
Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells.
“transduction” refers to the process where a virus transfers genetic material (DNA) from one cell to another, most commonly used in the context of bacteria where a virus called a bacteriophage carries DNA from one bacterium to another, essentially acting as a vector to transfer genetic information between cells; this is considered a form of horizontal gene transfer.
A. Conjugation.
The fertility factor is a plasmid, or extra chromosomal element, that allows for bacterial conjugation. Since the colony lacked the fertility factor conjugation is not the method of bacterial recombination that accounts for the change.
Side note: transformation is the genetic alteration of a cell resulting from the direct uptake and incorporation of exogenous genetic material from its surroundings through the cell membrane.
Transformation is a process by which bacteria acquire new genetic material from their environment
Transduction is the process by which bacteria gain genetic information though a vector such as a bacteriophage.
C. Prions.
A prion is a misfolded protein that induces misfolding in normal variants of the same protein, leading to cellular death.
After the infection of a cell, a viral particle must transport itself to the nucleus in order to produce viral proteins. What is the likely genomic content of the virus?
A. Double-stranded DNA.
Side note: Positive and negative sense RNA viruses are classified based on the polarity or sense of their RNA. The main difference between the two is that positive sense RNA viruses can be translated into proteins directly, while negative sense RNA viruses must be converted to positive sense RNA, via RNA polymerase, before translation. Negative sense RNA is not infectious by itself. Positive sense RNA is directly infectious because positive sense RNA is similar to mRNA can therefore be translated directly to protein synthesis via the rough endoplasmic reticulum.
Eukaryotic cells
Eukaryotic organisms can be unicellular or multicellular, and contain a true nucleus, enclosed in a membrane. Contain membrane bound organelles.
The cytoskeleton
Provide structure to the cell and helps it to maintain it shape. The cytoskeleton provides a conduit for the transport of materials around the cell via microfilaments, microtubules, and intermediate filaments.
Microtubules
Microtubules, unlike microfilaments, are hollow polymers of tubulin proteins. Micro tubules provide the primary pathway along which motor proteins like kynesin and dynein carry vesicles.
Cilia and flagella are motile structures composed of microtubules. Cilia are projections from a cell that are primarily involved in the movement materials along the surface of the cell. Flagella or structures involved in the movement of the cell itself such as the movement of sperm cells through the reproductive tract.
