The female gametophyte structure that produces eggs in nonvascular plants are called archegonia. The male structure that produces sperm are called antheridia. A gametophyt â¦ e is the part of the plant that is responsible for creating gametes AKA sexual reproductive cell (sperm or egg).
All American Express cards begin with '37,' followed by currency indicator (digits 3, 4), account number (digits 5-11), card number within account (digits 12-14), and check digit (digit 15).
Credit card numbers follow certain patterns. A credit card must have between 13 and 16 digits. It must start with: â¢ 4 for Visa cards. â¢ 5 for Master cards. â¢ 37 for American Express cards. In 1954, Hans Luhn of IBM proposed an algorithm for validating credit card numbers. The algorithm is useful to determine if a card number is entered correctly or if a credit card is scanned correctly by a scanner.