Question

QUESTION 13

1. Which of the following would occur if a mutation caused Kinase 1 to be unable to be phosphorylated? (Select all)

   		RTK would bind VEGF
   		RTK would phosphorylate itself
   		RAS would become active
   		The phosphorylation cascade would occur
   		The endothelial cell would divide

0.2 points   

QUESTION 14

1. Imagine that an endothelial cell has a mutation in several of the enzymes that perform mismatch repair. The endothelial cell replicates its DNA and then divides into two cells. The resulting cells will contain DNA that has

   		accumulated mutations missed by proofreading.
   		accumulated mutations missed by nucleotide excision repair.
   		accumulated Okazaki fragments.
   		eliminated mutations.
   		eliminated Okazaki fragments.

0.2 points   

QUESTION 15

1. An endothelial cell begins the process of mitosis. In which phase of mitosis would the cell get stuck if homologous chromosomes line up in the middle of the cell but the cohesion that holds sister chromatids together stays intact (does not split)?

   		Prophase (includes prometaphase)
   		Metaphase
   		Anaphase
   		Telophase

0.2 points   

QUESTION 16

1. Remember that some types of breast cancer cells produce VEGFs that bind to RTK receptors on their own cell membranes. Thus, continuously producing the signal to make themselves divide. You are an undergraduate researcher interested in VEGF signaling in breast cancer progression. You start by searching the peer-reviewed literature and discover two papers. The first used an inhibitory molecule, called A1, to inhibit the activity of RTK in human breast cancer cell lines. The authors concluded that A1 is a promising new treatment for breast cancer. The second paper injected the A1 into rabbits that had stage 2 breast cancer. The authors concluded that A1 is not a promising new treatment for breast cancer. Both papers used a robust and well controlled experimental design. Which of the following most likely accounts for the different statements about A1?

   		Scientists are human and humans are biased.
   		Scientists use each other’s work.
   		One paper made it through peer review and the other did not.
   		Conclusions change based on new evidence.

0.2 points   

QUESTION 17

1. You are interested in testing the ability of molecule B1 to inhibit RTK activity in breast cancer cells. You hypothesize that enabling the movement of B1 into breast cancer cells will reduce tumor growth. Which of the following are valid predictions that could be made from this hypothesis?

   		Injecting B1 into breast cancer tumors will reduce cancer progression.
   		Human breast cancer cells that are injected with B1 (using a cell needle) will show a significant reduction in the rate at which the cancer cells divide.
   		Tumor growth in rats with stage 2 breast cancer will be significantly slower after B1 is introduced into the body using a targeted cell method.

0.2 points   

QUESTION 18

1. To test your hypothesis, you set up 20 human breast cancer cell cultures in petri dishes. ten cultures are designated for the experimental methodology and ten are designated for the negative control. All 20 cultures begin with roughly the same number of cells. The experimental cultures are left to grow for 48 hours and then an experimental solution is added to the petri dishes. The experimental solution contains B1 bound to a benign viral vector which will inject the cells with the B1. Cell number is manually counted in each of the petri dishes every 12 hours for one week. What is the most scientifically robust methodology for the negative control?

   		No solution is added.
   		A solution with a known cancer treatment is added.
   		A solution without the B1 and without the viral vector is added.
   		A solution without the B1 and with the viral vector is added.

0.2 points   

QUESTION 19

1. $xid-11224910_1$

   Based on the results depicted above, which of the following conclusions is most accurate?

   		Fail to reject the null hypothesis. The experimental solution was effective at slowing the rate of cell division.
   		Fail to reject the null hypothesis at hours 36 and 48. The experimental solution became more effective over time at slowing the rate of cell division.
   		Reject the null hypothesis at hours 36 and 48. The experimental solution was effective at slowing the rate of cell division.
   		Reject the null hypothesis at hours 36 and 48. The experimental solution became more effective over time at slowing the rate of cell division.
   		Reject the null hypothesis. The experimental solution was effective at slowing the rate of cell division.

0.2 points   

QUESTION 20

1. Since your initial experiment had promising results you design several other experiments testing the ability of B1 to reduce breast cancer cell growth. You find that although B1 is effective at significantly slowing the rate of breast cancer cell division, B1 does not halt it completely. Therefore, you believe that B1 can be an important treatment against breast cancer but should be used in conjunction with another treatment. You start thinking about cell cycle regulator molecules…Manipulating the activity of which of the following regulator molecules could theoretically slow or stop cancer cell division? (select all)

   		Inactivating G1/S cyclin
   		Overactivating G1/S cyclin
   		Inactivating APC/C
   		Overactivating APC/C

Answer 1

Q 15. Anaphase is the right answer because the sister chromatids gets seperated in this mitosis phase.