The Longest Day Complete Warcraft Achievement Guide. 1  Battle Pet achievement The Longest Day doesn't need to feel like the longest day! With some planning and a good route mapped out, it's possible to zoom through this entire achievement without devoting an entire day to the activity.
Histones are spools of proteins that surround the chromosome and control the switching on of genes. National Human Genome Research Institute. Changes made to the protein spools that surround chromosomes are passed down generations, proving that inherited traits are decided by more than just DNA, says a new study.
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 phenotypical traits. Usage of the term having a gene (e.g., good genes, hair colour gene) typically refers to containing a different allele of the same, shared gene. Genes evolve due to natural selection or survival of the fittest of the alleles. The concept of a gene continues to be refined as new phenomena are discovered.