In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
What assembly sees alterations in genes?, Context: Genes can acquire mutations in their sequence, leading to different variants, known as alleles, in the population. These alleles encode slightly different versions of a protein, which cause different phenotype traits. Colloquial usage of the term "having a gene" (e.g., "good genes," "hair colour gene") typically refers to having a different allele of the gene. Genes evolve due to natural selection or survival of the fittest of the alleles.
Answer:
the population