All cells have a cell membrane, one or more DNA chromosome(s), and cytoplasm.
1 No curveballs before age 14. 2  8-10 years old 52 pitches per game and no more than 2 games pitching per week 11-12 years old 68 pitches per game and no more than 2 games per week.3  Seek good pitching mechanics coaching and work on developing good balance trunk and lower extremity strength. 8-10 years old 52 pitches per game and no more than 2 games pitching per week 11-12 years old 68 pitches per game and no more than 2 games per week.
An average 7 year old can throw from 30 to 40 mph. A 7 year old that is a freak and stand out and one of the best on the best of team can throw 45 and top out at 50 max.