What is alternative splicing?
a. Phosphorylation that leads to different types of post-translational regulation
b. mRNA processing that leads to different combinations of exons being spliced together
c. Folding that leads to proteins with alternative conformations
d. The outcome of regulatory proteins that leads to changes in the life span of an mRNA

Verified step by step guidance

1. Understand the concept of alternative splicing: Alternative splicing is a process during gene expression where a single pre-mRNA transcript can be spliced in different ways to produce multiple mature mRNA variants. This allows a single gene to code for multiple proteins.
2. Eliminate incorrect options by analyzing their definitions: Option (a) refers to phosphorylation, which is a post-translational modification, not related to mRNA splicing. Option (c) refers to protein folding, which occurs after translation and is unrelated to mRNA processing. Option (d) refers to mRNA stability and degradation, which is also unrelated to splicing.
3. Focus on option (b): This option describes mRNA processing that results in different combinations of exons being joined together. This is the correct definition of alternative splicing.
4. Relate the concept to biological significance: Alternative splicing increases protein diversity without requiring additional genes. It plays a critical role in development, cell differentiation, and adaptation to environmental changes.
5. Conclude that the correct answer is option (b), as it accurately describes the process of alternative splicing in mRNA processing.

Key Concepts

Alternative Splicing

Alternative splicing is a post-transcriptional process in which a single gene can lead to multiple mRNA variants by including or excluding certain exons. This mechanism allows for the generation of diverse protein isoforms from a single gene, significantly increasing the complexity of gene expression and protein function in eukaryotic cells.

Exons and Introns

Exons are the coding regions of a gene that are retained in the final mRNA transcript, while introns are non-coding regions that are removed during mRNA processing. The arrangement and selection of exons during splicing determine the specific protein product synthesized, influencing cellular functions and responses.

mRNA Processing

mRNA processing refers to the modifications that pre-mRNA undergoes before it becomes a mature mRNA molecule. This includes capping, polyadenylation, and splicing, which are essential for the stability, transport, and translation of mRNA, ultimately affecting gene expression and protein synthesis.