The diagram shows two cells taken from the same organism - HSC - SSCE Biology - Question 34 - 2015 - Paper 1

A disadvantageous mutation in a eukaryotic cell, like Cell B, may lead to dysfunction in cellular processes. For example, if the mutation affects a gene responsible for producing a crucial protein, it may disrupt the cell's normal function and impair growth or reproduction. In contrast, a similar mutation in a prokaryotic cell may affect its metabolic pathways, leading to reduced survival in competitive environments. The mutation could be less impactful in a larger population, but in a smaller, isolated group, it may threaten the entire species.

Current models of tRNA (transfer RNA) and mRNA (messenger RNA) have clarified the roles they play in protein synthesis. mRNA serves as a template for encoding genetic information, providing the sequence that determines the order of amino acids in a protein. The tRNA molecules transport specific amino acids to the ribosome, each tRNA recognizing a specific codon on the mRNA. This interaction ensures that amino acids are added in the correct sequence, leading to accurate protein assembly. Understanding this model allows us to appreciate how mutations in the DNA sequence can alter mRNA and ultimately affect protein structure and function.

Genes play a crucial role in embryonic development by regulating the expression of proteins that control growth and differentiation. For instance, specific genes can trigger the formation of body structures and systems at the right times during development. Mutations in these genes can lead to developmental abnormalities or changes in morphology. Moreover, genetic interactions can influence signaling pathways that coordinate the development process. By studying these gene actions, scientists can better understand the mechanisms driving embryonic development and the consequences of genetic alterations.