Which of the following genetic changes cannot convert a proto-oncogene into an oncogene? A mutation in the promoter of the proto
-oncogene, causing the normal protein to be transcribed and translated at an abnormally high level. A mutation that introduces a stop codon immediately after the codon for the initiator methionine. An amplification of the number of copies of the proto-oncogene, causing overproduction of the normal protein. A mutation within the coding sequence that makes the protein hyperactive. A genetic rearrangement where proto-oncogene coding sequence becomes fused with the promoter of a highly active promoter.
A mutation that introduces a stop codon immediately after the codon for the initiator methionine.
Explanation:
Pro oncogene is a gene altered by mutation.
Activating mutation of one of the two alleles of a proto-oncogene is what converts it to an oncogene. This can induce transformation in cultured cells or cancer in animals. Activation of a proto-oncogene into an oncogene can occur by point mutation, gene amplification, and gene translocation.
"A mutation that introduces a stop codon immediately after the codon for the initiator methionine."
Explanation:
There are multiple ways through which a proto-oncogene can get converted to an oncogene. It could either be due to a point mutation that occurs in the gene (or even its promoter), or amplification of the gene as a result of increased copies of the proto-oncogene that causes the normal protein to be produce in a larger quantity than needed. Gene translocation is yet another cause for its activation. However, a stop codon being introduced right after the start codon will not lead to activation of proto-oncogene, that will simply result in the production of a truncated, non-functional protein that will be degraded by the cellular machinery.
Photosynthesis is the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.
