1. What are oncogenes? A) Mutated tumor suppressor genes B) Mutated proto -oncogenes C) Genes regulating apoptosis D) Recessive genes 2. What is the function of p53 in normal cells? A) Promote cell division B) Trigger apoptosis in damaged cells C) Prevent DN A replication errors D) Repair single -strand breaks 3. Which of the following contributes to cancer formation? A) Accumulation of mutations B) Overactive apoptosis C) Loss of cyclins D) Rapid DNA repair 4. In eukaryotes,where does RNA splicing occur? A) Cytoplasm B) Ribosome C) Nucleus D) Golgi apparatus 5. What type of RNA does not code for proteins? A) MRNA B) tRNA C) SiRNA

1. B) Mutated proto-oncogenes<br />Oncogenes are mutated forms of proto-oncogenes, which are genes that normally promote cell growth and division. When these genes are mutated, they can cause cells to grow and divide uncontrollably, leading to cancer.<br /><br />2. B) Trigger apoptosis in damaged cells<br />The p53 protein is a tumor suppressor that plays a crucial role in preventing cancer. In normal cells, p53 detects DNA damage and triggers apoptosis, or programmed cell death, in damaged cells. This prevents the propagation of cells with damaged DNA, which can lead to cancer.<br /><br />3. A) Accumulation of mutations<br />Cancer is primarily caused by the accumulation of mutations in the DNA of cells. These mutations can be caused by various factors, such as exposure to carcinogens, radiation, or certain viruses. These mutations can disrupt normal cell growth and division, leading to the formation of tumors.<br /><br />4. C) Nucleus<br />In eukaryotes, RNA splicing occurs in the nucleus. During transcription, the pre-mRNA is synthesized, and the introns (non-coding regions) are removed, and the exons (coding regions) are joined together to form the mature mRNA.<br /><br />5. C) SiRNA<br />Small interfering RNA (siRNA) is a type of RNA that does not code for proteins. siRNA plays a role in the RNA interference (RNAi) pathway, where it binds to the complementary sequence of target mRNA and prevents its translation into protein.