To solve this problem, we need to analyze each statement and determine which one is incorrect:$\newline \bullet$Option 1: Male fruit fly is heterogametic.$\newline$ - In Drosophila (fruit fly), males are XY, making them heterogametic.$\newline$ - This statement is correct.$\newline \bullet$Option 2: In male grasshoppers, 50% of sperms have no sex-chromosome.$\newline$ - Male grasshoppers have an XO sex determination system, where males are XO and females are XX.$\newline$ - Therefore, 50% of the sperm will have no sex chromosome (O).$\newline$ - This statement is correct.$\newline \bullet$Option 3: In domesticated fowls, sex of progeny depends on the type of sperm rather than egg.$\newline$ - In birds, including domesticated fowls, the sex determination system is ZW, where females are ZW and males are ZZ.$\newline$ - The sex of the progeny is determined by the type of egg (Z or W) rather than the sperm.$\newline$ - This statement is incorrect.$\newline \bullet$Option 4: Human males have one of their sex-chromosomes much shorter than the other.$\newline$ - Human males are XY, where the Y chromosome is much shorter than the X chromosome.$\newline$ - This statement is correct.$\newline$Therefore, the incorrect statement is Option 3.