Write and explain in detail what is Gene regulation, what are the components and functions of each components in an operon and how the gene expression is regulated in prokaryotic and eukaryotic cells?

the second type of galaxy is called a barred spiral, which has a thing called a bar straddling the nucleus

if the type of the food available changes, then the frequency of beak types will change, because birds with beaks more suited to the available food will be more successful over time.