Question

28) Why do cells grow and become cancerous when p53 is mutated? A. The cancer cells stimulate blood vessel growth for nutrients and metastasis. B. p53 is a transcription factor which turns on a growth factor gene, thus stimulating mitosis. C. p53 is a transcription factor which turns on a gene for a growth-inhibitory protein. D. p53 is an oncogene which is integrated into genome from human papilloma virus.

29). If all humans are 99.9% same at DNA level, how do we distinguish between individuals in forensic cases? A. use non-coding STRs B. use hemoglobin gene which is highly variable C. use introns D. use promoter regions

30) To solve a problem with PCR we use a protein from Thermus aquaticus. Which of the following is the reason we use this protein? A. The protein is reverse transcriptase and it allows us to amplify RNA. B. The protein is RNA polymerase and allows for in vivo transcription. C. The protein is DNA polymerase from hot springs that can withstand high temperatures. D. The protein is a restriction enzyme which exposes ‘sticky ends’.

Answer 1

Ans 28. (C) p53 is a transcrption factor which turn on the gene for a growth inhibitory protein. p53 turn on the gene WAF1 or cip 1 which in turn controls the cell cycle.

Rest all the options are incorrect.

p53 is not a oncogene which is mentioned in two options is incorrect. p53 gene is a tumor suppressor gene that regulate and check the cell growth.

The cancer cells stimulate blood vessels growth for nutrient and metastasis is also incorrect because how is related to p53 protein directly.

The statement in itself is right but in context of p53 it is wrong.

Ans 29 (A) Use non coding STRs. Because it is a small tandem repeats present in human but all of us have different numbers of this tandem repeats. Thus, this technique have attracted attention in forensic science for crime and criminal detection.

All the rest options are incorrect.

Hemoglobin genes, introns and promoter regions are not a good choice. Promoter is highly conserved across species. Introns are also not so unique to the every individual as well as hemoglobin. Thus, the entity should be such that it is different across all individuals. So, all these three options are incorrect.

Ans 30. (c) The protein is DNA polymerase from hot springs that can withstand high temperatures. Because, in PCR you need that your DNA polymerase should able to carry ou polymerization at high temperatures like 72 degree C and and 92 degree C at Denaturation step.

Rest all options are incorrect.

The protein is reverse transcriptase and it allows us to amplify RNA is incorrect because mentioned enzymes is polymerase that add nuclotides to make DNA strand.

The protein is RNA polymerase allow for invivo transcrption is also incorrect because it is DNA polymerase.

The protein is restriction enzyme which exposes sticky end is again incorrect because it is DNA polymerase.

Dear student if you find the answer convincing please do give the feedback.