[Campbell Biology P.427] The discovery that over 90% of human protein-coding genes undergo a... | Practice Question

The discovery that over 90% of human protein-coding genes undergo alternative splicing, coupled with the observation that humans have a relatively low number of genes compared to their complexity, primarily suggests what about gene expression and evolution?

  • A: The complexity of an organism is directly proportional to its total gene count.
  • B: Alternative splicing significantly increases the diversity of proteins produced from a limited number of genes, contributing to organismal complexity.
  • C: Prokaryotic cells rely more heavily on alternative splicing for gene regulation than eukaryotic cells.
  • D: Gene duplication is the primary evolutionary mechanism for increasing protein diversity in eukaryotes.

Explanation

The text directly addresses the paradox of human complexity versus gene count by explaining that alternative RNA splicing allows a limited number of genes to produce a vast diversity of proteins. It states that over 90% of human protein-coding genes undergo alternative splicing, which 'greatly multiplies the number of possible human proteins, which may be better correlated with complexity of form than the number of genes.' This highlights alternative splicing as a key mechanism driving eukaryotic complexity beyond simple gene count.