Exam 1 Cell

What are the pluripotent stem cells?

Cells that can develop into any cell type in the body except extra-embryonic tissues.

Which of these best describes a metagenome?

the collected genomes from a specific microbiological population

A researcher is testing a new drug to reduce inflammation in cells. One group of cells receives the drug dissolved in a solvent, while another group receives only the solvent without the active drug. No change in inflammation is expected in the second group. What type of control is this?

Vehicle control

why does increasing magnification beyond a certain point fail to improve the clarity of an image viewed with a light microscope?

image clarity is limited by the resolving power of the microscope and not the magnification alone.

A researcher has sequenced a bacterial genome. They found that there are two possible genes that could act as a topoisomerase. They decide to perform an experiment.In this experiment, they will remove one of the two genes and then observe the process of replication. Based on your knowledge if the function of topoisomerase. What would they observe if the removed gene was a topoisomerase?

replication will slow then stall because there force required to unwind the double. helix will increase as replication proceeds without a way to release tension.

plants make glucose from photosynthesis, but they polymerize for storage. What chemical process would you associate with this polymerization reaction?

dehydration

which of these is not a basic trait of all cells?

Cells have compartmentalized regions that are separated by internal membranes including the nucleus, ER and the Golgi.

Which of the following experiments was not associated with the development of cell theory?

all of the above were critical to the formulation of our current understanding of cell theory

stem cells are now grown in bioreactors allowing for 3 dimensional cell cultures containing multiple cell types. These cell types are directed along developmental process to form small fragments of tissue called ______. They are currently being used to understand developmental processes, understand patient biology and screen fro new pharmaceuticals.

organoids

Induced pluripotent stem cells (IPSC) have both advantages and disadvantages to their use. which of the following best describes IPSCs?

Advantages:

the cells are derived from the patient so there is less chnace of tissues derived from IPSC being rejected following transplantation

Disadvantages
Due to their pluripotency, they can not be used directly for cell replacement as there is a change of teratoma (a type if cancer formation).

What are some of the ethical issues brought up by the use of the HeLa cell line?
a) the cells were taken without consent from the patient for utilization in research.
b) By sequencing the HeLa genome privacy issues would occur for the descendants of Ms. Lacks.
c) These cells were used in the development and testing of commercial products; however, there were not agreements on how the family might be compensated fro the use of the cells.

All of the above

This molecular interaction is generated by the interaction of partially charged molecules generated due to the polar covalent bonds often between the oxygen and hydrogen. Their combined force makes the DNA double helix highly stable.
a) covalent
b) Van Der wahls

c) hydrophobic
d) ionic

e) none of the above

e) non of the above

What is the most appropriate unit of measurement for the mist types of eukaryotic cells, for example an average white blood cell or an intestinal epithelial cell?

Micrometer (um)

cells are often small and it is hypothesized that there are concrete limits for the sizes of cells. Which of the following is not a limiting factor?

Limits imposed by organelle migration in free cytoplasmic space.

 You have joined the microscopy core at UT Southwestern medical center, and you are interested in the cytoplasmic location of the lysosome (organelle used in digesting food/foreign particles) in comparison to a small bacteria that survives phagocytosis. You hypothesize that pathogenicity of the bacteria is related to it ability to avoid fusing with the lysosome and being digested even when they are in the same cytoplasmic compartments (less than 10 nm apart). A collaborator sent them an image of E. coli being digested by the lysosome as a comparison.

A transmission Electron Microscope

The molecule can be classified as?

aldose and a hexose

the carbon highlighted by the arrow would be numbered as the:

5 prime carbon

What physical state of mater might you hypothesize for a collection of these molecules?

Liquid

this molecule would be classified as a

Unsaturated triglyceride

This industrial process (__________) could be used to convert the Cis-double bonds to trans double bonds; however, many states have been writing laws to reduce its utilization as it reduces ______ and increases _______ which correlates with decrease human helath.

hydrogenation, HDL and LDL

which of the following best describes this structure?

it is an RNA nucleotide based on the hydroxyl on the 2’ carbon

The nitrogenous base that is shown represents which class of base?

Pyrimidine

DNA replication involves a series of steps, including initiation, making primers, extension and connecting DNA fragments. the cell uses different enzymes in a particular order to accomplish these steps. Which of the following represents the correct general order of enzyme use?

Helicase, primase, DNA polymerases, ligase

In DNA replication, what is the difference between the leading and lagging strands?

After extension, the leading strand is continuous, while the lagging strand is composed of disconnected fragments.

In second generation sequencing, replication had been applied to obtain large amounts of sequence data. How does the identification of sequence differ from traditional Sanger sequencing?

The dyes associated with second generation sequencing block the 3 prime hydroxyl and then can be removed allowing further nucleotide polymerization. While Sanger sequencing uses a dye attached to a nucleotide without a 3 prime hydroxyl preventing polymerization.

One potential theory regarding the pathogenesis of Alzheimers disease is that is is a protein aggregation disorder. At the very least, the aggregates serve as a biomarker indicating the presence of disease The identity of the aggregates is?

both amyloid olaques and tau neurofibrillary tangles.

In a landmark study, dr. Lenski observed E.Coli bacteria for over 50,000 generations. He demonstrated that over time, the bacteria diversified so that some populations of the bacteria started metabolizing citrate, whereas ancestor populations couldn’t metabolize it before, This data supports the idea that:

cells evolve

the data in this figure supports which of the following?

a) cell theory

b) endosymbiotic theory

c) three domain taxonomic classification

B and C

The three domain system is based on the comparison of one gene utilizing movement on gels or the sequence of the rRNA gene. Why are scientist now reconsidering the relationship of the Eukarya and Archaea to such an extent that there is a discussion to reclassify life within at the domain level.

sequencing of whole genomes and expansion of the number of Archaea species has highlight the diversity in this group. Comparison of genes that are considered important eukaryotic genes has demonstrated that Eukaryotic organisms fall within the Archaea group and may not really be as separate as we once thought.

Neurofibullary tangles (NFTs) of the protein Tau have been identified in several different neurodegenerative disorders, like alzheimer’s disease and Frontotemporal Dementia, A study done in mice demonstrated that by eliminating Cys, NFTs were reduced significantly. Why do you think that the NFTs did not form?

The mutations impact disulfide convalent bond formation that stabilizes the NFTs quaternary structure.

Clinical trails are extremely costly and require many years to complete. The most interesting to investors is ________, as this phase of the process is the one that performs a large (1000’s of patients) placebo controls double-blind multi-center trail that often determines whether a drug will be cleared for sale or fail.

phase lll

The Umami flavoring (MSG) is an example of:

Amino Acid Functionality

This in vivo model system is extremely important to the field of cell biology, because it has an invariant cell lineage and the neural connections of the entire organism have been mapped out. This unique property allowed researchers to learn that cell death was a natural part of the developmental process of animals.

C. elegans

The spike protein of SARS-COV2 provides the virus with:

Cell specific and species-specific binding through an interaction with the ACE2 and/or NRP1 proteins in the lung and intestinal tract cells of humans

In the polar uncharged group, which amino acid can be post translationally modified with a phosphate group?

Ser