BIO3030 Chapter 24
Retroviral oncogenes are probably aberrant forms of normal cellular genes that regulate cell proliferation. Which of the following gene products are LEAST likely to be encoded by an oncogene?
Capsid proteins
Retroviral oncogenes are probably aberrant forms of normal cellular genes that regulate cell proliferation. Which of the following gene products are LEST likely to be encoded by an oncogene?
Capsid proteins
Eukaryotic cells with DNA damage often cease progression through the cell cycle until the damage is repaired. This type of control over the cell cycle is referred to as
Checkpoint control
About mouse p53 and DNA damage responses, which is CORRECT?
DNA damage induces p53 stabilization.
Hereditary Nonpolyposis Colorectal Cancer (HNPCC) is usually accompanied by mutations in caretaker genes that are responsible for
DNA mismatch repair
About ATP, which statement is WRONG?
Glycolysis does not generate net ATP.
All of the following statements are true about damage by ultraviolet light to DNA in living cells EXCEPT:
Neighboring phosphodiester bonds are cleaved
All immortalized cells are transformed cells.
No
Carcinomas are cancers of blood cells
No
Ras is a
None of these: a. growth factor. b. kinase. c. phosphatase.
About telomeres, which of the following is LEAST LIKELY?
Stem cells do not have telomerase activities.
Which is NOT correct about Philadelphia chromosome?
The fused gene functions as a tumor suppressor.
All of the following statements about monomeric G proteins are true EXCEPT
They regulate enzymes that synthesize cGMP
Which of the following is true concerning animal retroviruses?
They require an RNA-dependent DNA polymerase
Which of the following proteins belong to the control system that regulates cells past a certain point in late G1 (START)?
a. CDK4 c. Rb
"Transformed" cells in culture typically:
a. have loss of contact inhibition of growth b. form foci on a plate c. form tumors in experimental mice d. have unlimited number of population doublings
All of the following mechanisms have been shown experimentally to contribute to the formation of cancer cells EXCEPT
abnormally high energy reserves in cancer cells that cause them to divide too quickly
In females, all the cells in a tumor have the same inactive X chromosome. The reason for this is that
all of the cells in a tumor are derived from a single progenitor cell.
Consistent with the multi-hit model of tumorigenesis,
cancer cells may sequentially accumulate mutations and have different developmental stages
Which of the following CANNOT be a mechanism to convert a proto-oncogene to an oncogene?
chromosomal deletion
Telomerase
contains reverse transcriptase
A gain-of-function mutation in which of the following will bypass restriction point controls?
cyclin D
Abnormal activation of a receptor can happen in cancer cells by the following mechanisms EXCEPT:
deletion of the kinase domain
Which of the following is most likely NOT a hallmark of malignant tumor?
high demand on external growth factors
Src is a
kinase
Which of the following is characteristic of malignant tumors?
metastatic
All of the following are known to be part of a signal transduction cascade EXCEPT
phosphorylation of fibronectin
Which event will most likely NOT lead to tumorigenesis?
repair of DNA damages
Initiation of mitogenesis by epidermal growth factor and depolarization of the membrane of a skeletal muscle cell by acetylcholine are similar in that each
requires a ligand-mediated conformational change in a plasma-membrane receptor of the responding cell
Hereditary cancers typically exhibit loss-of-heterozygosity in
tumor-suppressor genes.
Hereditary cancers typically possess loss-of-heterozygosity in
tumor-suppressor genes.
Which of the following is LEAST likely to cause a proto-oncogene to become an oncogene?
A gene is moved into centromeric heterochromatin, silencing it's transcription
Which of the following is LEAST likely to cause a proto-oncogene to become an oncogene?
A gene is moved into centromeric heterochromatin, silencing its transcription
Which statement is NOT characteristic of caretaker genes?
Activities of caretaker genes increase the chances of tumorigenesis
If a cell has one chromosome in excess of the normal number of chromosomes present in the nucleus, it is referred to as
Aneuploid
