Question

Eukaryotic messenger RNA can undergo post synthetic processing after transcription and before translation. One of the processing steps is splicing, where portions of the RNA are removed and the remaining RNA are joined together. Classify the statements regarding mRNA splicing as true or false.

1. Splicing occurs while the mRNA is attached to the nucleosome

2. One mRNA can sometimes code for more than one protein by splicing at alternative sites.

3. Splicing occurs while the mRNA is still in the nucleus.

4. The spliceosome consists of five small RNA molecules and many associated proteins.

5. Proteins in the spliceosome recognize the 5' and 3' splice site sequences.

5. Proteins in the spliceosome recognize the 5' and 3' splice site sequences.

Answer 1

Splicing is a post-synthetic processing step that occurs after transcription and before translation in which introns are removed and exons are joined. Alternative splicing can produce multiple protein variants from one mRNA. Splicing occurs in the nucleus and involves proteins and RNA molecules called spliceosomes.

Step-by-step explanation:

Splicing is a post-synthetic processing step that occurs after transcription and before translation. It involves the removal of introns and the joining of exons to create a mature mRNA molecule ready for translation. The statements regarding mRNA splicing are as follows:

1. False: Splicing does not occur while the mRNA is attached to the nucleosome. The nucleosome is a structural unit of DNA packaging.
2. True: One mRNA can sometimes code for more than one protein by splicing at alternative sites. This process is called alternative splicing.
3. True: Splicing occurs while the mRNA is still in the nucleus.
4. False: The spliceosome consists of small RNA molecules called snRNAs and many associated proteins, not just five small RNA molecules.
5. True: Proteins in the spliceosome recognize the 5' and 3' splice site sequences.