Mutations can lead to lack of regulation, which overall, leads to genomic instability providing opportunities for uncontrolled growth — for example, cancer from the loss of cell cycle control. Proto oncogenes are normal genes that promote and regulate cell growth. Mutations to the proto oncogene itself could lead to oncogenes, which are cancer promoting.

Proto oncogenes promote proteins via proliferation with regulation. Oncogenes promote cell proliferation without regulation, leading to genomic instability, which can lead to cancer. A mutagen is a physical or chemical substance that can increase the frequency of mutations. A carcinogen is a substance that is directly involved in causing cancer.

p53 is a famous tumor suppressor, which blocks cell cycle progression preventing damaged/mutated DNA from being duplicated. Proto oncogenes are normal genes that regulate cell growth and proliferation. Oncogenes are mutated proto oncogenes that lead to unregulated cell proliferation. The checkpoints are in the S, G1, G2/M phases.

The correct answer here is the fiber connecting the chromosomes in the initial stages of mitosis. Remember that during mitosis, 1 pair of chromosomes becomes 2 new pairs. This requires the pair to split initially, duplicate, then break off into the new cells. The last stage of cell division is called anaphase, not a centromere. A centromere is the middle of a pair of chromosomes, not the individual chromosome. If you chose the daughter cell, remember that centromeres are not describing the new cell itself, but the connection between chromosomes inside the cell. 

The correct answer here is meiosis. Some of the options look challenging because you could assume RNA or DNA replication would result in gametes. However, the term gamete singularly refers to a sex-germ cell that is the direct result of meiosis. We can cancel out mitosis because that is specifically to replicate non sex related cells. 

The correct answer is that they are the fibers that help move the chromosomes towards a certain side of the cell during mitosis. If you chose the option about connecting a pair of chromosomes, remember that this is called a centromere and is also vital in mitosis. If you chose that the spindle fibers are only necessary in meiosis, remember that even in mitosis, fibers are needed to separate the individual chromosomes to form a new cell. Fibers do not act as the primer in RNA production  

Uracil is a nucleic acid found in RNA but not DNA. Therefore, if a question has uracil as one of the nucleic acids in the sequence, you know that you are dealing with a piece of RNA. RNA is genetic material that has been transcribed from a piece of DNA.

For DNA base-pairings, A-T must be paired up (2 hydrogen bonds) and G-C must be paired up (3 hydrogen bonds). For RNA base-pairings, A-U pair up instead of A-T.

The 5' to 3' linkages of DNA residues are via phosphodiester bonds, which are a type of covalent bond.

The following are the major steps in gene product modification:

1. Transcription of DNA into mRNA (primary transcript)

2. Pre-mRNA processes (mature transcript)

3. Translation of mRNA by tRNA (proteins)

4. Post-translational processing (modified protein)