Often different genes can interact in a way that influences the same trait. In the Blue-eyed Mary (Omphalodes verna), for example, there exists a gene with alleles that determine the color of flowers: blue or magenta. Another gene, however, controls whether the flowers have color at all or are white.
The regular price of buying miles from American is about 3.17 cents per mile ($29.50 per 1,000 miles plus a 7.5% Federal Excise Tax) â before a $30 Processing Charge per purchase â but with the maximum bonus offer, itâll actually drop your price down to just 2.02 cents per mile!
1 Fly and Buy miles will generally post to your Mileage Plan account immediately after the transaction is complete but may take up to two business days.  Fly and Buy miles purchased with a ticket that is later refunded will be subject to additional fees at the standard rate of 2.75 cents per mile plus applicable taxes.