Question

1) Which ONE of the following is NOT TRUE about PML-RAR:

a) the translocation is caused by ionizing irradiation and found in Hiroshima and Nagasaki victims

b) it is a fusion protein created by a reciprocal translocation found in acute promyelocytic leukemia

c) the fusion protein retains the ability of the retinoic acid receptor (RAR) to bind retinoic acid and DNA

d) PML contains zinc fingers and a coiled-coil domain, which are important for maintaining the structure of nuclear bodies

2) The CRISPR-Cas9 is a genome editing system. It was first discovered as…

a) The defense mechanism in bacteria against bacteriophages

b) The defense mechanism in bacteria against humans

c) he defense mechanism in zebrafish against bacteria

d) The defense mechanism in bacteria against macrophages

e) The defense mechanism in zebrafish against sharks

3) Which ONE of the following is NOT a method by which a tumor suppressor gene can lead to cancer:

a) incorporation into a retroviral genome

b) none of the answers (i.e., all of the other answers are true)

c) chromosomal deletion of the gene

d) loss of heterozygosity by non disjunction

e) methylation of the promoter of the tumor suppressor gene

4)

DNA Damage and the cell cycle:

Describe the mechanism by which DNA damage such as a double-strand break leads to cell cycle arrest.

Be sure to include:

a) how the pathway is regulated

b) why it is important to regulate the cell cycle during conditions of DNA damage

Answer 1

1. a) the translocation is caused by ionizing irradation and found in Hiroshima and Nagasaki victims.

2. a) the defence mechanism in bacteria against bacteriophages.

3. b) none of the answers are false

4.

When DNA damages through ionizing radiation, genotoxic chemicals ,it increases the level of P53 protein which determine to arrest the cell cycle in G1 phase.

B) when checkpoint mechanism detect that dna is damaged, cell cycle is halted. Otherwise it will cause cancer.

A) phosporylation is acted by cycline dependent kinase and check points regulate dna damage.